Environmental And Genetic Factors Influence Development Of Psychiatric Disorders

"The assumption about the primacy of environment has tended to give way over the past 25 to 30 years to a Zeitgeist favoring biological factors, especially those that trace biology to genetic inheritance," said study author Bruce P. Dohrenwend, PhD, of the New York State Psychiatric Institute and Columbia University, in New York City.

The development of drug treatments like Prozac, as well as the convincing results of twin studies by genetics researchers, has contributed to this change in focus. However, although genetic factors exert a powerful influence on the development of psychiatric disorders like post-traumatic stress disorder, depression, alcoholism, substance abuse, and antisocial personality disorder, they are not the sole cause, according to Dohrenwend.

The researcher cites Willy Loman, the depressed character in Arthur Miller1s play Death of a Salesman, as an example of someone whose problems have environmental as well as biological components, and as such, won1t be solved by Prozac alone.

"The explanation of his plight, perhaps like the explanation for the occurrence of much of the serious psychopathology in the general population, would be sought in sets of relationships in which he would be seen as both victim and creator of his fate," said Dohrenwend.

Dohrenwend summarized three lines of environmental research that strongly suggest that adversity is important in the development of psychiatric disorders. This research triad provides a "compelling analogy" to studies that emphasize genetics, according to Dohrenwend, whose research appears in the March 2000 issue of the Journal of Health and Social Behavior.

One line of research focusing on extreme situations concluded that post-traumatic stress disorder can develop in previously normal people exposed to uncontrollable negative events. A second line of research found a link between low socioeconomic status and the prevalence of psychiatric disorders. The third set of studies strongly suggests that social factors are more important than genetically related selection factors in the link between low socioeconomic status and the occurrence of disorders such as depression in women and antisocial personality, alcoholism, and substance abuse in men.

Analyses of the results of all three sets of studies suggest the same idea: the greater the uncontrollable changes following a negative event, the greater the likelihood that a disorder will develop. But the source of "uncontrollable change" varies with the part played by the behavior of the individual in the occurrence of the event.

The research was supported in part by the National Institute of Mental Health.

The Journal of Health and Social Behavior is a peer-reviewed quarterly publication of the American Sociological Association.