Depression Essay Example | Topics and Well Written Essays - 750 words - 3

Depression - Essay Example Secondly, females are more prone to depression than man and the ratio was worked out to be almost 1:2. There are several historical evidences indicates that the symptoms which are used to describes depression today were recognize in ancient times too. Even though there were wide understanding of depression and its symptoms till middle of nineteenth century there were little progress in terms of mechanistic aspect of depression. Than after people started gathering information regarding causes' of depression starting with Brain functioning, hormonal role, environmental influence and finally genetic basis of depression. Genetic composition of individual plays very important role in predisposition of depression. Epidemiological data indicates that there are almost 40%-50% cases have hereditary correlation with diseases condition and that is strong evidence to see depression as genetic disorder. Epidemiologic studies approximately show that around 40-50% of the depression caused is due to genetic reasons.(Sanders at al., 1999) This also leads to an understanding the depression highly heritable like several other common complex medical conditions like Type II diabetes, hypertension, asthma and certain cancers. But the study relating to depression has lead us to more confusion, since no certain genes have been yet discovered that confers to it. This process has been difficult since finding one gene responsible for causing depression is a complex phenomenon since a single gene will produce relatively small effect and would thus be very difficult to solve experimentally. It is also possible that different variants of genes are responsible to cause depression each family. (Nestler et al.,2002) The association of the location of TPH2 (Tryptophan hydroxylase) gene and the role of serotonin is being widely described and is also associated with depression. The TPH gene is responsible for depressive disorders and suicidal tendencies. The researchers have also indicated the role of the hydroxyindole acetic acids in Cerebrospinal fluid which is significant in suicidal tendencies. The location of serotonin transporter gene and the role of its polymorphism is significant is suicidal tendencies. (Kamrowska A., 2007). In 1999 Silber et al, studied the possible causes of greater depression among adolescent girls by examining variation in the influence of genetic and environmental risk factors among 182 prepubertal female, 237 prepubertal male, 314 pubertal female, and 171 pubertal male twin pairs. The patients were from the Virginia Twin Study of Adolescent Behavioral Development. The impact of life events on depression was particularly evident in the adolescent girls. The results clearly indicated that the increased heritability for depression in this group and its life long consistency clearly indicated that that it was largely mediated by genetic factors. The researchers could also perform model fitting which also showed that at least part of the liability to depression and to life events was linked to a common set of genes in the adolescent girls, and there was a notable developmental increase in the genetic variance for life events. The role of dysregulation of beta -serotonin (5-HT) neurotransmission is also known to be responsible for depression, anxiety disorders, bipolar disorder, autism etc. Although these conditions are treated with serotogenic drugs, the molecular mechanism by which 5-HT is involved in