What we got wrong about depression and its treatment.

The paradigm is shifting with respect to how we think about depression and its treatment. Some of that shift can be attributed to new findings with respect to its epidemiology and genetics and the rest can be attributed to the incorporation of a new perspective derived from evolutionary theory. In brief, depression is far more prevalent than previously recognized with the bulk of additional cases involving individuals who do not go on to become recurrent. Nonpsychotic unipolar depression (but not bipolar mania which likely is a "true" disease) appears to be an adaptation that evolved to facilitate rumination in the service of resolving complex social problems in our ancestral past. Cognitive behavior therapy appears to structure that rumination so that patients at elevated risk for recurrence do not get "stuck" blaming themselves for their misfortunes, whereas antidepressant medications may suppress symptoms at the expense of prolonging the underlying episode such that patients remain at elevated risk for relapse whenever they try to discontinue. This means that patients not otherwise at risk for recurrence may be put on medications that they do not need and kept on them indefinitely whether they need to be or not.