Experiencing chronic severe stress, particularly during critical periods of development, can lead to later symptoms of depression and anxiety. Furthermore, stress is thought to increase the propensity for drug addiction. In turn, chronic substance abuse can produce symptoms of depression and anxiety when the drug user is abstinent, increasing the likelihood of craving and drug seeking which can lead to re-taking the drug.

These observations lead us to believe that both chronic stress and substance abuse result in dysfunction of converging pathways in the brain that are involved in the production of mood and drug-reward. The students and research scientists in the Forster Laboratory test this hypothesis by studying the interaction between chronic stress and drugs of abuse at behavioral, endocrine and neural levels. The goal of this approach is to identify therapeutic targets within the brain in an attempt to ameliorate the long-term detrimental effects of stress and drugs of abuse.

The hippocampus is a brain region important for modulating mood and stress responses, and is implicated in depression. It is also one of the few brain regions that generates new brain cells in adults. This figure depicts already existing brain cells (green) and newly formed brain cells that were generated within a 24 hour period (red). Stress and drugs of abuse reduce the number of newly generated brain cells in this region. Photo taken by Jeffrey Barr, graduate student in the Forster Lab, BBS, Sanford School of Medicine, USD.

The hippocampus (pictured above) is a brain area important for modulating mood and stress responses, and is implicated in depression and addiction. Both chronic stress and drugs of abuse result in dysfunction of the hippocampus. Photo taken by Dr. Gina Forster, BBS, Sanford School of Medicine, USD.