Predictability of family history on subsequent psychiatric and substance abuse disorders? It is predictable

In the July, 2009 issue of the Archives of General Psychiatry, there is an interesting article which found that family history is predictive of the liklihood of psychiatric disorders in subsequent generations in the diagnoses of depression, anxiety, alcohol dependence,and drug dependence. Here is a snippet from the abstact:

Associations between family history of a disorder and clinical features of that disorder in probands showed consistent direction of effects across depression, anxiety disorder, alcohol dependence, and drug dependence. For these disorder types, family history is useful for determining patients' clinical prognosis and for selecting cases for genetic studies.