Depression is one of the most common forms of psychopathology. According to diathesis-stress theories of depression, genetic liability interacts with negative life experiences to cause depression.
Traditionally, most studies testing these theories have focused on only one component of the diathesis–stress model: either genetics or environment, but not their interaction. However, because of recent advances in genetics and genomics, researchers have begun using a new design that allows them to test the interaction of genetic and environmental liabilities – the G x E design.
Studies suggest that the neurotransmitter dopamine may play a role in the risk for depression. Early negative interpersonal environments (i.e. rejecting parents) have also been implicated. So, University of Notre Dame psychologist, Gerald Haeffel, and colleagues investigated whether a gene associated with dopamine interacted with maternal parenting style to predict episodes of depression.
The researchers studied 177 male adolescents from a juvenile detention center in Russia. These participants were ideal candidates for the study because depression rates rise so dramatically during this period in life. The researchers used a structured diagnostic interview to diagnose depression and a questionnaire to assess aspects of maternal parental rearing (i.e. physical punishment, hostility, lack of respect for the child's point of view, and unjustified criticism in front of others).