Comment on Scott Stossel’s NYTimes book review of Peter D. Kramer’s “Case for Antidepressants”: Depression is less specific than Multiple Personality.

The basis for the controversy over whether antidepressants work is that depression is a nonspecific diagnosis. Depressed patients are diverse.

Of the patients who fulfill the diagnostic criteria for depression, some do well on antidepressants, but others don’t. And the same is true of the effectiveness of psychotherapy for this heterogeneous population.

In contrast, a patient with alternate personalities and memory gaps has a relatively specific condition.

Most depressed patients do not have multiple personality, but among patients who do have multiple personality (undiagnosed and unsuspected), the presenting problem is often depression.

Sometimes antidepressants help patients with multiple personality, either because the patient has both depression and multiple personality, or because the antidepressant happens to make it more difficult for a problematic personality to take control.

If the patient has both conditions, the antidepressant may be needed even after problems with the multiple personality are resolved. But if the patient has only multiple personality (with the depressed mood as a secondary symptom of the multiple personality), then psychotherapy specifically designed for the multiple personality cures the depression as well.

My main point here is that, compared to depression, multiple personality is a relatively specific diagnosis.