Possible Link Between Depression and Genetics

Depression is the clinical term for an individual who experiences, among other things, terms of helplessness, depressed mood, and reduced interest in things they once enjoyed. The mental disease has been long linked to running through families, but it was unknown whether this was through the cause of environmental, or inherited, factors. Two studies, one by the New York times and one by an independent laboratory, sought to provide some insight to a linkage between individuals with depression and the gene 5-HHT. 5-HHT produced two alleles called "long" and "short". Both long and short alleles produced the same protein, however, the long allele produced much more of it than the short allele. 43% human population posssess the short allele, and 57% the long allele.



The study tested individuals with both long and short alleles, and when the subjects turned 26, polled to see which ones had depressive episodes after a stressful event. Both articles concluded that those with two short alleles for 5-HHT were more likely to develop depression, while those with two long ones were more likely to be completely unaffected.

While both studies provided affirmative evidence linking depression with 5-HHT, the New York Times article did not support its conclusion with data, while the independent laboratory did. Both studies only tested for stress and depression between the ages of 21 to 26. And it's also entirely possible that other genes, or epigenetic markers, could have a significant affect on an individuals susceptibility to depression. So as of now, despite the very good evidence to the contrary, it is safe to say a link between depression and one gene is inconclusive.

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