Psychiatric Genetics

• Genes and psychiatry: the classic theory
• Genes and psychiatry: the new paradigm
• Endophenotypes
• Traveling the hypothetical path from gene to mental illness
• Stress diathesis hypothesis
• Personality as buffer or amplifier of stress
• Degrees of genetic abnormalities and environmental stressors
• Summary

Psychiatric Genetics

After decades of research, genetics in psychiatry may finally be coming of age. Genetic models now exist that are generating rapid and significant progress in the quest to explain the role of genes in mental illnesses. The answers are not simple and the questions remain numerous and complex, but the results are exciting and have the potential to transform the practice of psychiatry and psychopharmacology.

Here we discuss the new paradigm for genes and psychiatry that has recently emerged. That paradigm conceptualizes genes not so much as direct causes of mental illness but as direct causes of subtle molecular abnormalities that create risk for mental illness. Genes may thus act by “biasing” an individual’s brain circuits toward inefficient information processing and possible breakdown into psychiatric symptoms under certain environmental circumstances.

Soon the modern psychopharmacologist in clinical practice may have tools to assess the risk of patients and their family members for various psychiatric disorders, the risk of suffering specific side effects of various drug treatments, and the likelihood that specific drugs will act effectively on their symptoms. In the future, a psychopharmacologist may even be able to investigate mental illness with information from the DNA of their patients, much as a crime scene investigator (CSI) already does for solving a mystery. Therefore, understanding the state of the art for genes and psychiatry can position psychopharmacologists to become early “CNS-Is” (“central nervous system investigators”) who, as the results of research pour into clinical practice, are able to utilize data from genetic analysis of their patients’ DNA.