When it comes to antipsychotic medication, it appears that psychiatry has come full circle. The very first antipsychotic, Thorazine, was introduced in 1952, and had originally been considered to be an antihistamine, a bit like Benadryl. Eventually, we understood that it had extraordinary effects on the delusions and hallucinations of schizophrenia.
Over the years, many other antipsychotics have been introduced, and they are all effective at reducing psychotic symptoms, as their name implies. But over the past decade, they have also won FDA approval for treating bipolar disorder. Now, the companies marketing these drugs have their eyes on depression, which represents a far larger potential market than either schizophrenia or bipolar disorder. On November 21, Abilify received FDA approval as an add-on treatment for major depression (see the news item here). This follows closely on the heels of a study published a couple of weeks ago in the Annals of Internal Medicine showing that Risperdal was effective as an adjunctive depression treatment.
How effective are these drugs for depression? Not terribly. The Abilify data, for example, shows a remission rate of 26% vs. 16% for placebo augmentation, meaning that 1 out 10 patients would be expected to respond to an Abilify-induced boosting of their current antidepressant. The design of this study was somewhat manipulated in order to make sure Abilify beat placebo, a fact brought to my attention by this excellent post in Cl Psych. Nonetheless, the Risperdal data are very similar, and I'm convinced that atypicals provide a small antidepressant effect. Enough of an effect to overcome the potential side effects? That's unclear.
What is abundantly clear is that drug companies are going to be pushing both psychiatrists and primary care doctors to think of "antipsychotics" as "antidepressants." Look closely at the data before you buy the message!