Even with modern genome analysis techniques, it is difficult to identify genetic factors affecting risk for depression. Since we know that depression is hereditary, it is reasonable to deduce that eventually we will be able to identify its genetic loci. To figure this out we need to look at larger sample studies which is challenging.
The authors of the study which have come up with this hypothesis are currently working on finding this loci. This research is import because depression is one of the most common, disabling and costly mental health conditions. By understanding its causes, such as genetics and environmental factors, it will help us focus on the interactions of these implications for prevention and treatment. Depression runs in families and based on studies of twins, it is estimated that genetic factors account for 40% of the risk. Genes are suggested to affect depression by influencing dopamine and serotonin neurotransmission.
A study from 2003 suggests that an interaction between a gene variant affecting serotonin and stressful life events can cause depression. However, studies have had conflicting results when examining gene by environment (GxE) effects. This is why researches are looking to do a large scale GxE study in hopes it will lead to further discoveries. The goal of this research is to more closely identify the particular genes that are possibly a cause of depression to better help prevent the disease and improve the lives of those who suffer from the disease.
Related Article: http://www.nature.com/mp/journal/v14/n12/full/mp200848a.html