I know that the current topic is depression, however I think it is important to try and understand the parts of depression that are discussed far less than the ‘typical’ symptoms such as loss in affect, anhedonia, etc. To that point, I think that it would be worthwhile to explore the end result of some cases of depression (which, unfortunately, is more common than anyone would like it to be): suicide. In addition to suicide, I think it is also important to touch on self-injurous behaviors (such as cutting, burning, hair-pulling, biting, etc.). These actions, while uncomfortable and often difficult to think about, are fairly common things in individuals who have been diagnosed with depression. Of course, not everyone who is depressed exhibits these behaviors, and by that same token, not everyone who behaves this way is diagnosed with depression. However, these behaviors seem to be rather comorbid with this particular illness, and this is why I looked for some articles regarding the etiology of suicide as it relates to depression.
There was on article in particular that really caught my attention — in case you are interested in looking at the paper in more depth, here is the citation: Mann, J.J., Brent, D.A., & Arango, V. (2001). The neurobiology and genetics of suicide and attempted suicide: A focus on the serotonergic system. Neuropsychopharmocology, 24, 467-477.
Essentially, this article explored the possible biological and genetic contributors to individuals who have either attempted suicide (in vivo brain imaging) or who have committed suicide (post-mortem tissue studies). They focused their study on the serotonergic system, which I thought was particularly interesting, considering that many of the drugs used to treat depression involve this system (SSRIs). These researchers argue that there are genetic and biological precursors that lead an individual to be ‘more susceptible’ to suicide. They suggest that personality traits, such as impulsivity and aggression, in addition to genetic factors, set a person up to be more likely to attempt suicide. What do you think about this argument? In particular, I had some issue with how they presented their argument–as being more biological than psychological (essentially even bypassing the psychology involved all together). What if these in-brain changes are actually a result of the intial depression? What if their psychological responses to their environment are the ‘precursors’ to these biological changes, which then could perpetuate the issue (much like what we discussed in class-about the vicious cycle of depression).
Unfortunately, I feel like this article had few answers, if any. It leaves us in the same place we were in for the depression discussion, where there are so many different possibilities that it’s almost impossible to untangle the ’causes’ from the ‘symptoms’. Regardless, I think that the article is a step in the right direction–just like any sort of terminal illness, suicidality is a serious affliction, caused thousands (if not more) deaths per year the world over. Depression does not have to be a terminal illness. There can be ways to treat it, but we need to really put our resources into investigating this psychopathology in order to better understand the etiology, and to better help our loved ones and friends who may be at risk.
On Psychology and Neuroscience 
The tricky thing about studying brains of people who have committed suicide is that they are no longer alive and can give no helpful feedback. Also, even if we study brains of people who have only attempted suicide, the direction of causation in the biological state of the brain is unclear. It could be interesting to study the brains of people with suicidal thoughts against those who have attempted suicide and those who have committed suicide. Maybe some sort of progression could be seen.
LikeLike
Yikes! This is a whole new side of depression that I haven’t really pondered about. Why are there only some depressed individuals that think about suicide? Are there varying levels of depression and suicide is one of the deeper levels or is it a whole different neurosis all together?
LikeLike
A great paper related to this topic by a friend of mine in Nature Neuroscience last year:
Nat Neurosci. 2009 Mar;12(3):342-8.
Epigenetic regulation of the glucocorticoid receptor in human brain associates with childhood abuse.
McGowan PO, Sasaki A, D’Alessio AC, Dymov S, Labonté B, Szyf M, Turecki G, Meaney MJ.
Douglas Mental Health University Institute, 6875 LaSalle Boulevard, Montreal, Quebec, H4H 1R3, Canada.
Maternal care influences hypothalamic-pituitary-adrenal (HPA) function in the rat through epigenetic programming of glucocorticoid receptor expression. In humans, childhood abuse alters HPA stress responses and increases the risk of suicide. We examined epigenetic differences in a neuron-specific glucocorticoid receptor (NR3C1) promoter between postmortem hippocampus obtained from suicide victims with a history of childhood abuse and those from either suicide victims with no childhood abuse or controls. We found decreased levels of glucocorticoid receptor mRNA, as well as mRNA transcripts bearing the glucocorticoid receptor 1F splice variant and increased cytosine methylation of an NR3C1 promoter. Patch-methylated NR3C1 promoter constructs that mimicked the methylation state in samples from abused suicide victims showed decreased NGFI-A transcription factor binding and NGFI-A-inducible gene transcription. These findings translate previous results from rat to humans and suggest a common effect of parental care on the epigenetic regulation of hippocampal glucocorticoid receptor expression.
LikeLike
A level of susceptibility for suicide is a crucial topic in biology. I wonder if there is anything that can be done before suicide is a feasible option for an individual. Although this article seems to be traveling more on the brain street of the intersection, it is important to look at historical factors in a person’s life to determine the likeliness he or she will attempt suicide. I hope there is a way we can decrease the frequency of suicide and depression in the future
LikeLike
One possible solution to the causation issue could be to perform a longitudinal study of individuals who exhibit extremely high levels of aggression and impulsivity, and see if these traits are predictors of suicide attempts. If these personality traits merely correlate with but do not precede suicide attempts, these traits might actually be a result of personality change resulting from long-term depression.
LikeLike
Hannah H. talked today about people with a specific genetic trait having a lower threshold for negative life events. Maybe personality characteristics make certain people more susceptible to these negative life events also. Maybe their personalities interfere with their ability to properly cope with the situation and so they turn to suicide. Just a thought… but it is definitely not all about the biology!
LikeLike