The recent controversy surrounding antidepressant drugs and suicide risk has raised important questions about the risks and benefits of treating depression, the most common mental disorder and the leading cause of disability worldwide. The debate also has underscored a troubling fact about depression treatment: beyond drugs such as fluoxetine (Prozac) and sertraline (Zoloft), there is a paucity of therapeutic options. And the situation is not likely to change any time soon.

Selective serotonin reuptake inhibitors, or SSRIs, have been the mainstay of depression therapy since fluoxetine was approved in 1988. SSRIs act to increase the amount of serotonin, a brain chemical involved in mood regulation, available to nerve cells.

Some newer antidepressants target a different neurotransmitter called norepinephrine or act on both norepinephrine and serotonin. These drugs revolutionized depression treatment, offering hope to millions of people in the form of once-daily pills. Drug companies rode the wave, churning out copycat or slightly tweaked formulas, heavily promoting the drugs to patients and doctors, and racking up billions in sales.

But things have changed in recent years. In 2004, the Food and Drug Administration (FDA) required drug makers to include a “black box” warning on all antidepressant labels to reflect new evidence that the drugs moderately increase suicide and suicidal thinking in children and adolescents. After the FDA’s action, prescriptions for the drugs plummeted 20 to 30 percent, according to different estimates.

In December 2006, the FDA determined that the drugs carried a higher risk of suicide for young adults up to age 25, but not for older adults. As with children, the greatest risk is during the initial weeks of treatment, though it is not clear why. The FDA issued a public health advisory about the risk and is expected to require updated labeling to reflect the new findings.

Widely reported in the press, the findings and drop in prescriptions have left many psychiatric and public health experts worried that people will abandon their medications or that doctors will stop prescribing the drugs altogether. Untreated depression, especially in severe cases, also can be deadly.