Category Archives: Disorders and Diseases

The Genetics Behind Huntington’s

Huntington Disease is a rare genetic condition that most people have never even heard of unless a) they study it b) they personally know someone with the disease or c) they are a fan of House. Luckily for me only a) and c) apply in this situation. However, I believe Huntington’s like a variety of other diseases is something the public needs to be educated about because awareness really is the greatest way to inspire research into any field.

As autosomal dominant disorder this makes Huntington’s especially dangerous because as a dominant trait a person only needs one affected allele to develop the disorder. Were the trait recessive such as the trait for hemophaelia, for example, then the likelihood of having Huntington’s is significantly lowered. When a trait is autosomal this means that it is no carried by any of the sex chromosomes (X or Y), rather is carried by any of the other 22 chromosomes the human body has. In Huntington’s the gene affected is located on chromosome 4, specially on the p (upper, shorter) arm.

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The symptoms of Huntington’s has already been discussed on a previous post on basal ganglia disorders; however, in summation it results in damage to the striatum and cerebral cortex causing changes in personality including mood swings, involuntary movements known as hypokinesia and eventually dementia. As is common with most genetic disorders, the symptoms do not appear until adulthood. In Huntington’s the symptoms usually arise around mid-age, but unfortunately it can arise earlier than our 30s or 40s if unlucky. Once symptoms start appearing the person usually has about another 5 to 15 years until death. The age at which symptoms appear directly correlates with the genetics behind the abnormal gene.

Huntington’s is part of numerous diseases including varies ataxias and fragile X syndrome that result due to trinucleotide repeat. Specifically, Huntington’s is due to a repeat of the CAG trinucleotide. Normal alleles carry about 10 to 35 copies, but those suffering from Huntington’s and various other neurodegenerative diseases have more than 40 repeats. People with around 60 repeats with develop Huntington’s around the age of 20. These repeats in CAG result in the production of a “mutant protein” that eventually fill the striatum and cerebral cortex causing degeneration and ultimately death of these brain cells. In healthy individuals the gene involved in Huntington’s encodes for a large protein known as huntingtin (Htt), which when normal enhances the production of a protein (BDNF) necessary for the survival of the cells in the striatum and cerebral cortex.

Stay tuned for a post later this week on current experimental treatment on Huntington’s! Thank you for reading :)

Citation:

Cummings, Michael. “Genetics of Behavior.” Human Heredity: Principles and Issues. 9th ed. Belmont: Brooks/Cole, 2011. 405-06. Print.

Anorexia and Autism?

A new study lead by Professor Simon Baron-Cohen of Cambridge University suggests that girls with anorexia have a higher than average “number of autistic traits” (University of Cambridge, 2013). These traits include an “above average interest in systems” and a below average empathy score (ibid). Considering the rigid personality, attitudes and behaviours of anorexics and their obsessive thought patterns in relation to body weight, body image and eating patterns it is not difficult to see how they can be interpreted as typical of autism.

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n the study, first published the Journal of Molecular Autism, Baron-Cohen et al. assessed 66 girls between the ages of 12 and 18 with anorexia but no history of autism for autistic traits. A control group of over 1,600 neurotypical teens in the same age group were also given the same assessments including the the Autism Spectrum Quotient (AQ), Systemising Quotient (SQ) and the Empathy Quotient (EQ). Results showed that compared with the control group, the anorexic girls were five times more likely to score in the autistic spectrum. More than 50% of the anorexic girls fell into the “broader autism phenotype” compared with only 15% of the control (ibid). Furthermore, the anorexic girls also scored a higher SQ and lower EQ which also points towards an autistic personality.

As interesting as these results are there is indeed a practical application. Cases of autism are far more prevalent in males; however, Baron-Cohen’s findings show that perhaps autism in young girls is being overshadowed by a diagnosis of anorexia. Dr Tony Jaffa, co-leader of the study confirms that the new correlation between autistic traits and anorexia will give health professionals and researchers a new means to help those suffering from the eating disorder. He remarks:

“For example, shifting their interest away from body weight and dieting on to a different but equally systematic topic may be helpful. Recognising that some patients with anorexia may also need help with social skills and communication, and with adapting to change, also gives us a new treatment angle”

Mental Health Stigma

mentalillnessThis will be my fiftieth post on Cognitive Consonance and because I wanted to make it special by posting something engrossing and clever, I just ended up not posting anything at all. I put far too much pressure on myself, argh! Instead of trying so hard, I am just going to discuss something really important to me personally.

As I think is quite common with people interested in the field of psychology, I have and still continue struggle with depression and anxiety. I am not trying to evoke pity or sympathy because in actual fact, I am quite proud of how far I have come in the past 2 years. It takes quite a long time to learn to accept that you have a disease or disorder and that it is not just all in your head (ha, a pun! :P). Allowing yourself to be treated might make you feel like a failure; like there is something wrong with you because you just can’t get over your problems by yourself. It takes a great deal of strength to recognise that something is wrong.  I believe this is true for more than just mental disorders. Suffers of any ailment go through a period of denial. In fact, denial is the only stage of the Kuebler-Ross model that has been proven to be universal. I believe that the first step of any form of recovering or acceptance is recognising that something is wrong because it means admitting that you are vulnerable. Personally, I struggled with feelings of guilt. I felt like I had no reason to feel unhappy or anxious and that I should just get over myself. The truth is that a mental disorder, like any other medical ailment, needs to be treated. Treatment of course does not always mean in the form of medication. In fact, numerous types of mood disorders as well neuroses, have been treated very successful with cognitive-behavioural therapy.

mentalillness1I digress, in November I posted an ‘Inspiring Video‘ on schizoaffective disorder by a youtuber called Jonny Benjamin as part of the “I’m JustHuman Project.” In the video he discusses his experience with schizoaffective disorder and its impact on his life. However, more importantly his video is part of a project to reduce the stigma that surrounds mental health issues. Many people today mistake the symptoms of schizophrenia for depression and those of depression with a physical ailment (Myers 2001). Furthermore, a large majority of the population think that mental illness equals violence. In truth, most people that suffer from mental illness are no more violent than the rest of the population. The differences are easily accounted for by the symptoms of certain kinds of disorders, specifically the paranoia of paranoid schizophrenia or the lack of empathy seen in psychopaths. Just like certain personality types are more likely to engage in criminal behaviour, such as narcissistic or aggressive people, so are people with certain types of disorders. What I am trying to say is that there is no reason for the fear and stigma that surrounds mental illness.

mentalillness2Lastly, I want to say that mental illness in most cases is something that you cannot see from outside. Just like many who suffer from autism express frustration with the fact that they look normal but feel different, this frustration

is also common with people suffering from mental disorders. Those of us who have suffered from anxiety and depression learn how to conceal the truth. One of my closest friends showed up at the same mood disorder support meeting as me. Neither one of us had any clue the other person was going through the same thing. I believe that says a lot because the truth of the matter is that we are not so different from anyone else. Keeping that in mind, I feel it is important to be kind, supportive and patient to whomever you can because you never truly know what people are going through. Dealing with disorders such as depression, panic disorder, generalised anxiety disorder, OCD, etc. can easily be concealed and is a personal issue, but at the same time there is no reason to feel ashamed. We are in fact just like everybody else, the only difference is that we have deal with issues that impact our day-to-day lives. It is a struggle but one that is more than worth enduring.

Basal Ganglia Disorders: Parkinson’s and Huntington’s Disease

My last post was exclusively about basal ganglia and the reason for this was to help clarify the parts of the brain directly involved in two very infamous disorders: Parkinson’s and Huntington’s Disease.

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Parkinson’s Disease

Parkinson’s disease is far more recognized that Huntington’s disease; however, thanks to the character Thirteen on the tv show House that might be changing. Parkinson’s disease effects about 1% of all people over the age of 50; however, as you can see from the video posted below, this is not always the case. Another example is actor Michael J. Fox, who was diagnosed with Parkinson’s at the age of 30. He has since become an activist for the cure of Parkinson’s, which led him to found the Michael J. Fox Foundation. It is not that uncommon to know someone with the disease. Many people can in fact recognize it based on the very characteristic tremors.

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Parkinson’s is classified by hypokinesia. The symptoms of Parkinson’s include slowness of movement or bradykinesiadifficulty in initiating ‘willed’ movements or akinesia, increases muscle tone or rigidity, and of course, tremors in the hands and jaws even at rest. Many  of those who suffer from the disease will eventually show signs of cognitive decline. More specifically, the substantia nigra’s input to the striatum. This input features the neurotransmitter dopamine, which facilitates the activity of the motor loop by activating cells in the putamen. As noted in the previous post, the putamen forms an inhibitory connection with neurons in the globus pallidus, which then forms an inhibitory connection with the thalamus (VLo). Due to the depletion of dopamine, the ‘funnel’ between VLo and the supplementary motor area (SMA) closes. As a result, the victim of Parkinson’s will have impaired motor function with symptoms such as ones listed above.

Treatment Options for Parkinson’s Disease

Even through Parkinson’s cannot be cured, therapies do exist to try to ease or deter the symptoms. Most therapies aim at enhancing the levels of dopamine delivered to the caudate nucleus and the putamen. The most common type of medication is known as L-dopa, which is a precursor for dopamine. This means that it participates the chemical reaction that produces dopamine. This treatment does alleviate some of the symptoms; however, it cannot do anything to stop the progressive course of the disease, nor slow the rate of cell degeneration in the substantia nigra. Currently, experiments are being conducted to test whether graftng non-neural cells, manipulated to produce dopamine, into the basal ganglia can help. Also, stem cell research shows promise to one day provide an effective treatment as well.

Huntington’s Disease

Whereas Parkinson’s is characterized by hypokinesia, Huntington’s is characterized by hyperkinesia or excessive movement. As tragic as Parkinson’s disease is, Huntington’s does seem far more frightening. A hereditary, progressive and always fatal disorder, Huntington’s  symptoms include dyskinesia or abnormal movements, dementia and disorder of the personality. The scariest part of the disorder is that the symptoms do not appear until adulthood, so unless the person knows that they have a history of the disorder, they can easily pass on the genes of Huntington’s to their children without even knowing that they have it. Genetic tests can be performed to find out for sure, but for many people it is too late at that point. The name Huntington’s comes from the abnormal gene carried by the patient. The first and most notable sign of the disease is known chorea: spontaneous, uncontrollable movements with rapid, irregular flow resulting a flicking movement in various parts of the body. In fact, Huntington’s disease can also be called Huntington’s Chorea. The devastating effects of the disease is due to the profound neuron loss in caudate nucleus, putamen and globus pallidus as well as cell loss in any other part of the cerebral cortex. The fact that Huntington’s can strike any part of the brain means that many patients suffer a variety of different symptoms, sometimes making it difficult to diagnose without a genetic test. Damage to the basal ganglia results in a loss of inhibitory output to the thalamus (VLo) resulting in the abnormal movements.

brainslice3Unfortunately, due to the progressive nature of the disorder and the genetic component, treatment for Huntington’s is virtually non-existent. Most patients with the disorder have their symptoms treated with various medications ranging from anti-depressants to sedatives and anti-psychotics.

 

Mental Retardation and Dendritic Spines

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Dendrite is Greek for “tree-like” and to explain what they do in the simplest terms possible, they receive electrochemical signals from other neurons and then pass these signal down to the soma or neural cell body. Dendrites play a critical role in determining the frequency of the action potential, which drives the electrical signal down axons of the body of the neuron towards the axon terminals. Dendrites are so essential that their architecture is a great indicator of the complexity of our neural connections. In fact, our brain function depends on strong synaptic connections, connections which are cultivated during infancy and early childhood.

Unfortunately, as with all things complex, sometimes something goes wrong in the developing process. Mental retardation occurs when there is a disruption in this early refinement of dendrites that results in cognitive impairment severe enough to disrupt adaptive behaviour. There is a wide array of genetic disorders and poor environmental conditions that can result in mental retardation. For example, Down Syndrome and PKU (both genetic disorders), accidents during pregnancy and childbirth, maternal infections with rubella, Fetal Alcohol Syndrome and environmental impoverishment. Poor environmental conditions in young children such as poor nutrition, isolation and neglect can even result in brain damage severe enough to cause damage to these sensitive dendrites.

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Healthy dendrites have spines that look like small balloons that hang of the dendrite. In cases of mental retardation dendritic spines are very thin and long, resembling the dendritic spines of a fetus. This is clearly seen in the top most image, a) and c) are healthy dendrites. This clear difference reflects the failure of normal circuits in the brain’s development. Studies by Marin-Padilla and Purpura have discovered a correlation between extent of dendritic spine damage and degree of mental retardation.

Citations:

Bear, Mark F., Barry W. Connors, and Michael Paradiso. “Neurons and Glia.”Neuroscience: Exploring the Brain. Baltimore, MD: Lippincott Williams & Wilkins, 2006. 43. Print.

Images courtesy of google images.

 

The Ebola Virus: What is it actually?

The Ebola Virus has been getting a lot of news coverage recently with a massive outbreak in West Africa. As of March this year the death toll is the highest of any Ebola outbreak ever recorded. The exact number is still increasing, but over one thousand individuals have been exposed with causalities now around 800 (Sender, 2014). Obviously this virus is deadly and scary, but what exactly is it? My family and I were discussing these outbreaks over dinner, and I thought that a great way to learn about it is to do some research.

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History 

Firstly, the Ebola virus causes Ebola virus disease (EVD) or Ebola haemorrhagic fever (EHF) in humans. It is part of Genus Ebolavirus and the Filoviridae family. The Genus Ebolavirus consists of five distinct species:

  1. Zaire ebolavirus (EBOV)
  2. Bundibugyo ebolavirus (BDBV)
  3. Reston ebolavirus (RESTV)
  4. Taï Forest ebolavirus (TAFV)
  5. Sudan ebolavirus (SUDV)

Not all of these species are dangerous to humans. However, BDBV, EBOV and SUDV are all associated with mass outbreaks of EVD in Africa. Out of these three, EBOV is the most deadly. According to the World Health Organisation (World Health Organization, 2014) the RESTV species can infect humans, but they do not cause severe illness or death as is the case with the other three. Since 1994, EBOV and the TAFV species has infected chimpanzees and gorillas (WHO, 2014). Outbreaks of severe EVD have also been found in macaque monkeys in the Philippines in 1989, 1990 and 1996. Not only do outbreaks in non-human primates cause concern for them, but it also creates concern that one day EVD in humans can be brought on by the TAFV species.

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Map of outbreaks of the Ebola virus in Africa by strain and confirmed contractions. Distribution of Ebola Virus Outbreaks 1979-2008, South Africa Created by: Zach Orecchio University of South Florida Geography Dep. Data Source: http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/ebola/ebolamap.htm

EVD in humans first appear in 1976 in Western Africa. The virus occurred in two simultaneous outbreaks in two different villages, in Nzara, Sudan and Yambuku, Democratic Republic of Congo. The outbreak in the DRC fell along the Ebola River, hence the name.

Aetiology

As mentioned above, the Ebola virus is a virological taxon part of Genus Ebolavirus. The Ebola virus, as an a cellular virus, replicates through a host cell. The virus attaches itself to the host cell’s receptors through glycoproteins. Then it fuses its own viral membrane with the cell’s membrane. This fusion process allows the virus to release its nucleocapsid (which contains the virus’ genetic material) into the cytoplasm of the host cell. Using the cellular machinery of its host, the virus creates viral proteins and then as the protein levels rise, new nucleocapsids are also created (Noda et al. 2006). As the new genetic material rises in number, budding occurs. Budding is where the virus, creates an “envelope” using the host’s cell membrane. Essentially, creating a new virus from the host itself (ibid). Eventually, as more and more viruses are created from the host, the host will be destroyed.

Ultimately, the number of viruses in the body begins to wreak havoc. In humans and other primates, the virus eventually causes extreme hemorrhagic fever and in most cases, death.

Transmission 

Ebola is transmitted to humans through contact with infected bodily fluids (ie. blood, secretions). Contact can be direct through broken skin or mucous membranes or indirectly with environments contaminated with the fluids.The incubation period (2 to 21 days) means that people can get infected by a person that does not even know they are ill. It is natural that family and friends want to mourn their recently deceased loved ones; however, the mourning process can become a high risk activity. Often, the burial ceremonies involve direct contact with the deceased person before the virus has died. In other words, healthy individuals are being infected by their infected, deceased loved one (WHO, 2014). Other common ways Ebola is transmitted is through recovered individuals and working in the healthcare field. Any one that has sex with a man recovered from Ebola can become infected from their semen. The semen carries the Ebola virus up to seven weeks after recovery, hence the man will feel healthy, engage in sexual activity and unknowingly, infect others (WHO, 2014). Healthcare professions are at high risk when the proper sanitary precautions are not enforced or possible. Lastly, people that work with infected primates or pigs can also become infected with the disease; however, the likelihood lesser than contact with a diseased human. As stated above, not all viruses that have infected animals are capable of causing EVD in humans.

Currently there is debate that fruit bats, in particular genera Hypsignathus monstrosus, Epomops franqueti and Myonycteris torquata are natural hosts for Ebola. This hypothesis is based on an overlap between the EVD outbreaks and the geographic distribution of fruit bats in Africa.

Symptoms and Diagnostics

A major concern when treating Ebola is that it carries symptoms similar to many other diseases. According to the World Health Organization (2014) “malaria, typhoid fever, shigellosis, cholera, leptospirosis, plague, rickettsiosis, relapsing fever, meningitis, hepatitis and other viral hemorrhagic fevers” all need to be ruled out. Of course with equipment available in the Western world, this process is quite simple. Ebola can be precisely diagnosed by running a variety of diagnostic tests including but not limited to electron microscopy, antigen detection tests and virus isolation by cell culture (WHO, 2014). These diagnostic tools can rule out other disorders by checking for low white blood cell and platelet counts plus elevated liver enzymes (WHO, 2014).

In Africa, however, these diagnostic tools are not always available. Therefore, it is important that the symptoms are clearly laid out and understood. EVD causes “severe acute viral illness” with symptoms including headache, muscle pain, weakness, fever and sore throat. These initial symptoms then progress into vomiting, rash, diarrhea, reduced kidney and liver function and sometimes internal and/or external bleeding.

Treatment and Prevention 

Currently there is no vaccine for EVD despite many being tested. Those infected with EVD are being treated with various drug therapies, which are always being improved and remedied. Until a vaccine or a truly efficient treatment has been discovered, patients with EVD are being treated in intensive care where they are holistically cared for, keeping them hydrated through IV with an electrolyte solution.

As the mortality rate for Ebola is so high (as high as 90%) the best way to treat Ebola is to prevent it from happening in the first place (BMC, 2014). In other words, the best way to handle Ebola is to prevent it. For the general public this means educating them on how the disease is transmitted, teaching them proper sanitation procedures and providing them with ways to keep clean and safe such as making condoms and cleaning products readily available.

For more information do your own research or check out some of the websites in my bibliography.

Thank you for reading!

Emma

Bibliography 

Assembly and Budding of Ebolavirus. (n.d.). Retrieved August 6, 2014, from

Ebola virus. (2014, May 8). Retrieved August 6, 2014, from http://en.wikipedia.org/wiki/Ebola_virus

Ebola Virus. (2014, August 4). Retrieved August 6, 2014, from http://www.cdc.gov/vhf/ebola/

Ebola Virus. (2014, June 17). Retrieved August 6, 2014, from https://www.bcm.edu/departments/molecular-virology-and-microbiology/ebola

Ebola virus disease. (2014, April 8). Retrieved August 6, 2014, from http://en.wikipedia.org/wiki/Ebola_virus_disease

Ebola virus disease. (2014, April 1). Retrieved August 1, 2014, from http://www.who.int/mediacentre/factsheets/fs103/en

Ebola virus disease. (2014, January 1). Retrieved August 6, 2014, from http://www.who.int/mediacentre/factsheets/fs103/en/

Noda, T., Ebihara, H., Muramoto, Y., Fujii, K., Takada, A., Sagara, H., … Kawaoka, Y. (2006, September 29). Assembly and Budding of Ebolavirus. Retrieved August 6, 2014, from Noda, T., Ebihara, H., Muramoto, Y., Fujii, K., Takada, A., Sagara, H., … Kawaoka, Y. (n.d.). Assembly and Budding of Ebolavirus. Retrieved August 6, 2014.

Sender, H. (2014, July 31). Where Is The Ebola Virus? Outbreak Map Shows Virus Deaths In West Africa. Retrieved August 6, 2014, from http://www.ibtimes.com/where-ebola-virus-outbreak-map-shows-virus-deaths-west-africa-1645012

Depression: Symptoms, Aetiology and Treatment Options

Symptoms 

Depression is a serious affective disorder that affects millions of people in the world, approximately 5% of the population. In the United States alone approximately 33 million people will suffer from depression at some point in their life (Bear, 2007). In addition, the disorder is the leading cause of suicide. Despite its high prevalence, however, stigma still also remains high. A primary reason for the stigma surrounding any mental disorder is a misunderstanding of the symptoms and causes.

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Even though depression strikes people differently, the cardinal symptoms are lowered mood and feelings of dejection, a lack of pleasure or interest rather than sadness. Accompanying symptoms include changes in appetite, fatigue, insomnia or hypersomnia, diminished concentration, feelings of worthlessness and/or guilt and recurrent thoughts of death and/or suicide (Bear, 2007). Depression can be one half of bipolar disorder but also occur on its own and in varying degrees of severity. Usually, for a diagnosis of major depression, the cardinal symptoms of depression must be present every day for approximately 2 weeks. Importantly, the cause of depression cannot be linked to a bereavement. This clear distinction is what separates depression from sadness.

Types of depression include chronic depression of dysthymia, major or clinical depression, atypical depression and manic depression. Chronic depression or dysthymia is usually less severe than major or clinical depression; however, it can be more disabling in that the symptoms are long-term (2 years+) or recurrent throughout a lifetime. Major or clinical depression is more severe; however, the symptoms do not last longer than 2 years and is not typically recurrent. Approximately 17% of sufferers have chronic symptoms.  It is important to note, however, that when depression is left untreated, recurrence is far more likely. Manic depression is found in bipolar disorder, to find out more click here. Finally, atypical depression is when a person suffers from the accompanying symptoms rather than the cardinal symptoms.

Aetiology and Treatment Options 

Biological basis 

Affective or mood disorders such as depression alter the typical function of the brain. Many different parts of the brain are usually affected at the same time, but the major system involved is the hypothalamic-pituitary-adrenal system (HPA). Exaggerated activity in the HPA system is common in people with anxiety and affective disorders. Specific to depression, blood cortisol levels are heightened as is the concentration of corticotropin-releasing hormones (CRH) in the cerebrospinal fluid.

Monoamine hypothesis

The monoamine hypothesis of depression states that a deficit in monoamines causes mood disorders. Monoamines include serotonin and catecholamines (inc. dopamine, noradrenaline, norepinephrine).  Current anti-depressants focus on this theory of depression. Anti-depressants inhibit the re-uptake of of monoamines, increasing the concentration of them in the synaptic cleft. The great benefit of anti-depressants is that they promote long-term, adaptive changes in the brain reducing the possibility of another depressive episode. Unfortunately, not all depressed people find anti-depressants effective. This can mean that either the treatment does not work for them at all or they require a greater dosage. Furthermore, it can takes week for depressants to take affect. Lastly, anti-depressants can raise levels of norepinephrine, which makes anti-depressants less effective. As anti-depressants are not always effective,  patients with prolonged depressive episodes may seek alternative treatment. Electroconvulsive therapy (ECT) and therapy are both options. ECT is mainly used in extreme cases because it can offer immediate relief. However, ECT is controversial due to the danger of memory loss. This is not surprising considering ECT is a localised seizure controlled by keeping the patient under anaesthesia. It is unknown exactly how ECT works; however, the hippocampus has been implicated. The hippocampus is involved in regulating CRH levels and the HPA system.

Types of anti-depressants include: selective serotonin re-uptake inhibitors, serotonin-noradrenaline re-uptake inhibitors, tricyclic anti-depressants and monoamine oxidase inhibitors. For people with bipolar disorder, lithium is also used to stabilise mood primarily the mania but has been shown stabilise mood overall.

Diathesis-Stress hypothesis 

The diathesis-stress hypothesis proposes that mental disorders have a genetic component that predisposes us to mental illness. Certain life stressors then makes us susceptible to mental illness actually presenting themselves. As such, traumatic childhoods full of abuse and/or neglect can leave a child at high risk for developing mental disorders. Tragically, children whose poor treatment is due to mentally ill caregivers, this cycle becomes hard to break. However, according to the diathesis-stress model, a trigger is not enough to bring forth mental illness without a genetic foundation. This genetic foundation goes hand in hand with the HPA system. Of course this does not mean that only traumatised children will suffer from mental health disorders. Individuals that have experienced a highly stressful life even such as divorce, moving away from home, changing schools, becoming ill, etc. will also be at risk are they predisposed to mental health issues.

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In a healthy individual, cortisol activates hippocampal glucocorticoid receptors, which inhibit the the HPA system. However, in a depressed individual there is a flaw in the feedback system. On a molecular level there is a diminished hippocampal response to cortisol due to reduced number of  glucocorticoid receptors. Here the genetic component of depression comes into play; glucocorticoid receptors are the product of gene expression. Hence, an individual with few glucocorticoid receptors is more susceptible. Fittingly, the amount of glucocorticoid receptors are epigentically influenced, early sensory experience can alter the number as well. This means that a childhood where we are well looked after, loved, cared for, kept safe and happy can protect us from developing depression even if we disposed to at birth. This illustrates how important the interaction of nature and nurture is. Think Voldemort vs Harry Potter. Despite the traumatic death of his parents, the one year of unconditional love and Lily’s sacrifice protected him not just magically but neurologically. Interestingly, in an interview with Oprah Winfrey, JK Rowling discuss this exact point.

 

Citation 

Antidepressants . (n.d.). Antidepressants. Retrieved July 18, 2014, from http://www.nhs.uk/conditions/Antidepressant-drugs/Pages/Introduction.aspx

Bear, M. F., Connors, B. W., & Paradiso, M. A. (Eds.). (2007). Neuroscience(Vol. 2). Lippincott Williams & Wilkins.

Pinel, J. P. (2010). Biopsychology (8th ed., International ed.). Harlow: Pearson Education.

What the Heck is an HPA Axis & What Does it Have to do with Stress?. (n.d.). About.com Fibromyalgia & Chronic Fatigue. Retrieved July 18, 2014, from http://chronicfatigue.about.com/od/cfsglossary/g/hpa_axis.htm

Bipolar Disorder

My most recent post showcased the artist Isti Kaldor who has bipolar disorder. This post will explain the basics of the disorder. Quite a few celebrities have come forward stating they have bipolar disorder including Catherine Zeta Jones, Demi Lovato and Stephen Fry. If you want to know the true scope, there is a wikipedia page dedicated to celebrities known to have it. Despite their very public work lives, with our limited insight into their personal lives it is difficult to really know much about the disorder. Stephen Fry, however, did a brilliant documentary on his experiences dealing with his bipolar disorder called Stephen Fry: The Secret Life of the Manic Depressive, which is available in full on YouTube.

Symptoms and Types 

As the title says, bipolar disorder is sometimes also called manic depression, but bipolar disorder is its official name. Characterised as a recurrent mood disorder, it consists of repeated episodes of mania interchanged with episodes of depression. The depressive episodes include similar but less severe symptoms of major depression such as changes in appetite, insomnia or hypersomnia, fatigue, feelings of worthlessness, guilt, inability to concentrate and suicidal thoughts. As such, the symptoms can be managed with anti-depressants. The manic periods, however, are the opposite in some respects. Symptoms consist of grandiosity, decreased need for sleep, talkativeness, flight of ideas, short attention span, and impaired judgement. It is believed that the correlation between bipolar disorder and celebrities is that those with the disorder usually experience these manic highs with bursts of creativity and inspiration. Unfortunately, the manic period can also result in promiscuity and complete loss of inhibition much like the effects of alcohol. As with any disorder, the range and complexity of symptoms varies greatly from person to person.

Bipolar comes in two general forms: type I and type II. Type I is marked by manic episodes (with or without incidents of major depression), and occurs in about 1% of the population, equally among men and women. Type II is marked by hypomania (milder form of mania that is not associated with marked impairments in judgment of performance) and is always followed by milder depressive periods.

Aetiology 

Numerous twin studies and most notably the one conducted by McGuffin and colleagues (2003) have shown that there is a high concordance between monozygotic twins with “67% MZ vs. 19% DZ.” Also, even though there is a high correlation with depression and mania, the manic component appears to be significantly more heritable in monozygotic twins. We do know that bipolar disorder affects our neurochemical pathways as treatment of lithium and anti-depressants do help alleviate the drastic mood swings. However, the actual structural component is yet to be properly determined. Studies by Bearden et al., 2001 admit that even though “dysfunction is implicated in bipolar illness patients supported by reports of relatively greater impairment in visuospatial functioning, lateralization abnormalities, and mania secondary to RH lesions” there is still not enough conclusive evidence to draw a clear link between right hemisphere dysfunction and bipolar disorder.

Strakowski et al., 2005 on the other hand using MRIs have found compelling examples of damage to the prefrontal cortical areas, striatum and amygdala that predates that onset of symptoms, which suggests that abnormal brain structure could in fact play a quintessential role in onset of the disease. Furthermore, if further studies can confirm these findings, it could offer psychiatrists and neurologists a revolutionary way of pre-symptomatic diagnosis. As of 2012, Strakowski et al. have reached a “general consensus” that bipolar type I occurs due to abnormalities within networks that control emotional behaviour such as the prefrontal cortex and limbic area, specifically the amygdala.

Treatment 

To date the most effective treatments for bipolar disorder include lithium (used to target the manic episodes), anti-depressants such as SSRIs, monoamine oxidase and tricyclics. Other types of medication such as anti-anxieties and anti-psychotics are used in some cases depending on the severity of the symptoms. In addition to medication, therapy has also been proved to significantly reduce the psychological stress of the disorder.

Citations:

Bear, Mark F., Barry W. Connors, and Michael Paradiso. Neuroscience: Exploring the Brain. Baltimore, MD: Lippincott Williams & Wilkins, 2006. Print.

Bearden, C. E., Hoffman, K. M. and Cannon, T. D. (2001), The neuropsychology and neuroanatomy of bipolar affective disorder: a critical review. Bipolar Disorders, 3: 106–150. doi: 10.1034/j.1399-5618.2001.030302.x

Malliaris, Yanni,. “1.7 Aetiology of Bipolar Disorder.” 1.7 Aetiology of Bipolar Disorder. BipolarLab.com, 20 Aug. 2010. Web. 03 Aug. 2013.

Strakowski, S. M., Adler, C. M., Almeida, J., Altshuler, L. L., Blumberg, H. P., Chang, K. D., DelBello, M. P., Frangou, S., McIntosh, A., Phillips, M. L., Sussman, J. E. and Townsend, J. D. (2012), The functional neuroanatomy of bipolar disorder: a consensus model. Bipolar Disorders, 14: 313–325. doi: 10.1111/j.1399-5618.2012.01022.x

ADHD/ADD: Symptoms, Aetiology and Treatment Options

Symptoms

In 2012, CDC data showed that 11% of school children in the US had been diagnosed with ADD/ADHD. It remains unclear why these figures are rising. Perhaps any or all of theses things are contributing: constant changes in diagnostic criteria that are expanding the symptomology, a greater acceptance of neurological disorders has prompted more people to step forward and accept a diagnosis, a shift in society that is actually increasing the rate of ADD/ADHD or even just misdiagnosis. One of the major changes in the DSM-V diagnosis is the recognition of adults with ADD/ADHD. Previously, ADD/ADHD has merely focused on the symptoms observed in childhood onset. In fact, the majority of children that develop the disorder go on to experience a variety of difficulties into adulthood. Being able to recognise ADHD as a long-term condition will hopefully improve the level of care for adults with a childhood diagnosis.

ADD

The symptoms of diagnosis can be broken down into two major categories: inattention and hyperactivity with impulsivity. Classic examples of these behaviours include: difficulty to failure to pay attention to details, difficulty organising tasks, fidgeting, excessive talking and inability to remain still or seated for a prolonged period. In order to be diagnosed with ADD/ADHD according to DSM-V guidelines, a child must present with six symptoms in either or both the inattention criteria and hyperactivity and impulsivity categories. Accordingly, the disorder can present in three ways: combined, predominately inattentive and predominately hyperactive-impulsive presentative. Adults (over the age of 17) must be present with a minimum of five symptoms. For both children and adults, these symptoms must be present for 6 months prior to diagnosis and should interfere with normal, daily life. Finally, these symptoms should be present in two or more settings, before the age of 12 and not singularly in conjunction with any other mental disorder.

Inattention Symptom – Taken directly from the DSM-V

  • Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or with other activities.
  • Often has trouble holding attention on tasks or play activities.
  • Often does not seem to listen when spoken to directly.
  • Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., loses focus, side-tracked).
  • Often has trouble organising tasks and activities.
  • Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time (such as schoolwork or homework).
  • Often loses things necessary for tasks and activities (e.g. school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).
  • Is often easily distracted
  • Is often forgetful in daily activities.

Hyperactivity and Impulsivity Symptoms 

  • Often fidgets with or taps hands or feet, or squirms in seat.
  • Often leaves seat in situations when remaining seated is expected.
  • Often runs about or climbs in situations where it is not appropriate (adolescents or adults may be limited to feeling restless).
  • Often unable to play or take part in leisure activities quietly.
  • Is often “on the go” acting as if “driven by a motor”.
  • Often talks excessively.
  • Often blurts out an answer before a question has been completed.
  • Often has trouble waiting his/her turn.
  • Often interrupts or intrudes on others (e.g., butts into conversations or games)

I was very fortunate to receive permission to use a first hand report of how ADHD/ADD feels. Below are his experiences in his own words. Please check out the Reddit post where he discusses his experiences with ADHD/ADD. It is linked in the reference section under the author Jonathan Michael. His personal experience really helped my understanding of what these symptoms feel like, not just what they are.

“ADD is almost like having a regulator switch turned off in my head…I feel like my mind is racing at 90 miles per hour, constantly thirsting to take in information and sense perception all around me.”

“It’s not that I can’t “pay attention”, it’s that I’m paying attention to almost everything around me and can’t consciously order which is “most important” to pay attention to fast enough, or sometimes at all.”

“ADD isn’t about “becoming bored”, it’s about losing the natural instinct to be able to prioritize what should be focused on instead of what shouldn’t be…For us, we literally lose chunks of time because we were so wrapped up in something else.”

Psychiatrist Edward M. Hallowell, M.D. describes ADHD/ADD as such, and Jonathan Michael mentioned in his post that he found it a very accurate metaphor for the disorder. 

“In ADD, time collapses. Time becomes a black hole. To the person with ADD it feels as if everything is happening all at once. This creates a sense of inner turmoil or even panic. The individual loses perspective and the ability to prioritize. He or she is always on the go, trying to keep the world from caving in on top.”

Aetiology and Treatment Options 

Genetics

Researchers suggest a strong correlation between genetics and ADD/ADHD. A meta-analysis of 20 international twin studies revealed a heritability estimate of 0.76 for ADHD, making it the most heritable psychiatric disorder (2). However, despite a high concordance rate between monozygotic twins (72-83%) and fraternal twins (21-45%), pinpointing what genes are different has proven difficult. One of the main reasons it has been so hard to map the genetic component to the disorder is because many genes seem to be implicated. This makes sense because ADD/ADHD is so complex that it is far more likely the phenotypes found result from the additive characteristics of many different genes. Not only that but the variation in symptoms suggests the possibility that ADD/ADHD involves endophenotypes. In other words, ADHD has hereditary characteristics associated with it but that are not a direct symptom of  it or dependent upon it.

ADD Brain

Natalie M. Zahr, Ph.D., and Edith V. Sullivan, Ph.D. “Translational Studies of Alcoholism Bridging the Gap” Alcohol Research & Health, Volume 31, Number 3, p.215- (2008)[1]

The Brain 

As with genetic factors, the brain regions involved in ADHD/ADD are not completely clear either. One region that appears to be most involved is the prefrontal cortex. The prefrontal cortex’s main role is executive function – planning, self-control and attention. Catecholimanergic (dopamine and noradrenaline) neurotransmitter pathways in the prefrontal cortex have been implicated. Symptoms of ADD/ADHD reflect problems in executive function. Drug therapies prescribed to individuals target these catecholaminergic pathways by inhibiting the re-uptake of dopamine and noradrenaline to increase the levels of these neurotransmitters in the synaptic cleft. Common drug treatments that act as a reuptake of inhibitor of dopamine an/or noradrenialine have methylphenidate, dexamfetamine or atomoxetine as an active ingredient. These active ingredients are stimulants which may seem counterintuitive when treating a hyperactivity disorder. However, as dopamine and noradrenaline in the prefrontal cortex increase self-control, attention, planning, etc. stimulating the release of these neurotransmitters is suitable. Unfortunately as with all drugs, those used in treatment of ADD/ADHD have side effects that sometimes outweigh the benefits of the treatment for some. Common side effects of Ritalin f.eg. includes depression, irritability, anxiety, aggression, reduced sex drive, heart palpitations and more. Other options include behavioural therapy which works on central executive tasks such as goal setting, impulse control, planning and organisation.

Common ADHD/ADD drugs:

  • Concerta XL (methylphenidate)
  • Dexamfetamine
  • Elvanse (lisdexamfetamine)
  • Equasym XL (methylphenidate)
  • Medikinet (methylphenidate)
  • Ritalin (methylphenidate)
  • Strattera (atomoxetine)

Diet and Environment

Researchers suggest that damage or trauma to a foetus’ brain or trauma in early childhood can in some cases lead to the development of ADHD/ADD later in life. A  foetus exposed to drugs, alcohol, cigarettes and/or high levels of stress due to their mother’s habits or environment whilst in the womb are more likely to develop ADHD. From birth into childhood, brain diseases or infection, trauma during birth, head injury or exposure to secondhand smoke are also seen as risk factors. Some parents argue that diet or supplements reduce the symptoms of or prevent ADHD; however, little evidence supports this belief. A few studies have found that children with ADHD have lower levels of fatty acids, but it remains unclear whether this actually plays any role in the pathogenesis of the disorder. A poor family environment, a difficult upbringing or many life upheavals in early life are found more often in children with ADHD, but as of yet there is no way of knowing whether a difficult family environment acts as a stressor or if related genes in ADHD put the family at risk for more familial conflicts and unlawful behaviour. Importantly, as with any disorder or even personality a poor familial or social environment aggravates any imperfect aspects of our character. As I emphasise with any post on mental health, the key is to recognise the true severity of the disorder and to respect those who fight through it on a daily basis.

For those seeking help for ADD/ADHD:

  • Contact your local GP
  • Speak to a family member or friend
  • http://www.nhs.co.uk/ (UK)
  • http://www.youngminds.org.uk/ (UK)
  • http://www.mentalhealth.org.uk/ (UK)
  • http://www.help4adhd.org/ (US)
  • http://www.addhelpline.org/ (Global)
  • http://www.cdc.gov/ (US)

References

American Psychiatric Association. (2013). The Diagnostic and Statistical Manual of Mental Disorders: DSM 5. bookpointUS.

Attention Deficit Hyperactivity Disorder. (2012, January 1). Retrieved November 10, 2014, from http://www.nimh.nih.gov/health/publications/attention-deficit-hyperactivity-disorder/index.shtml#pub5

Faraone SV, Perlis RH, Doyle AE, et al.: Molecular genetics of attention deficit hyperactivity disorder. Biol Psychiatry 2005, 57:1313–1323.

Hallowell, E.M (2012). What’s it Like to Have ADHD?. [ONLINE] Available at: http://www.huffingtonpost.com/edward-m-hallowell-md/what-adhd-feels-like_b_1627463.html. [Last Accessed 10 November 2014].

Khan, S. A., & Faraone, S. V. (2006). The genetics of ADHD: a literature review of 2005. Current Psychiatry Reports, 8(5), 393-397.

Michael, J. (2014). My husband was diagnosed with ADD because he can’t focus on reading or similar tasks. I can read a book all day but simply *cannot* focus on a movie or a TV show. My mind will not stay focused. How come he has ADD and I don’t?. [ONLINE] Available at: http://np.reddit.com/r/NoStupidQuestions/comments/2b6bt9/my_husband_was_diagnosed_with_add_because_he_cant/cj2e6a6. [Last Accessed 20 July 2014].

Millichap, J. Gordon, and Michelle M. Yee. “The diet factor in attention-deficit/hyperactivity disorder.” Pediatrics 129.2 (2012): 330-337.

Rutherford, D. (2014, January 24). What causes ADHD? Retrieved November 10, 2014, from http://www.netdoctor.co.uk/adhd/whatcausesadhd.htm

Symptoms and Diagnosis. (2014, September 29). Retrieved November 10, 2014, from http://www.cdc.gov/ncbddd/adhd/diagnosis.html