Antipsychotics, originally designed to control the hallucinations and delusions seen in schizophrenia, have been expanding their domain in recent years.

Nowadays, they're widely used in bipolar disorder, depression, and as a new paper reveals, increasingly in anxiety disorders as well.

The authors, Comer et al, looked at the NAMCS survey, which provides yearly data on the use of medications in visits to office-based doctors across the USA.

Back in 1996, just 10% of visits in which an anxiety disorder was diagnosed ended in a prescription for an antipsychotic. By 2007 it was over 20%. No atypical is licensed for use in anxiety disorders in the USA, so all of these prescriptions are off-label.

Not all of these prescriptions will have been for anxiety. They may have been prescribed to treat psychosis, in people who also happened to be anxious. However, the increase was accounted for by the rise in non-psychotic patients, and there was a rise in the rate of people with only anxiety disorders.

The increase was driven by the newer, "atypical" antipsychotics.

Whether the modern trend for prescribing antipsychotics for anxiety is a good or a bad thing, is not for us to say. The authors discuss various concerns ranging from the side effects (obesity, diabetes and more), to the fact that there have only been a few clinical trials of these drugs in anxiety.

But what's really disturbing about these results, to me, is how fast the change happened. Between 2000 and 2004, use doubled from 10% to 20% of anxiety visits. That's an astonishingly fast change in medical practice.

Why? It wasn't because that period saw the publication of a load of large, well-designed clinical trials demonstrating that these drugs work wonders in anxiety disorders. It didn't.

But as Comer et al put it:

An increasing number of office-based psychiatrists are specializing in pharmacotherapy to the exclusion of psychotherapy. Limitations in the availability of psychosocial interventions may place heavy clinical demands on the pharmacological dimensions of mental health care for anxiety disorder patients.

In other words, antipsychotics may have become popular because they're the treatment for people who can't afford anything better.

These data show that antipsychotics were over twice as likely to be prescribed to African American patients; the poor i.e. patients with public health insurance; and children under 18.

Comer JS, Mojtabai R, & Olfson M (2011). National Trends in the Antipsychotic Treatment of Psychiatric Outpatients With Anxiety Disorders. The American journal of psychiatry PMID: 21799067