Medication & Melancholy
Unraveling the jumble of data on depression, drugs, and kids
Sketchy data. Teenagers and adults in their early 20s are at the highest risk for suicide. Each year about 20 percent of adolescents contemplate suicide; by the end of high school, 1 in 10 has attempted it, with almost 2,000 succeeding each year. About half of those who die suffer from major clinical depression. Advocates for the use of antidepressants point out that the teen suicide rate increased from 5.9 to 11.1 per 100,000 between 1970 and 1994 but declined to 7.4 per 100,000 in 2002, just when the drugs were increasingly being prescribed for children.
These numbers reveal not only the scope of the problem but also the vast difference between the state of contemplating suicide--also called suicidal ideation--a suicide attempt, and an actual suicide. Ideation, it seems, is part of adolescence for 1 in every 5 kids in a high school classroom. A suicide attempt, however, becomes murkier in terms of reporting: Is self-cutting a suicide attempt or a way of relieving tension? Of course, it depends on the patient, but cutting alone, according to psychiatrists, is not attempted suicide.
Since the black-box warnings, two large-scale epidemiological studies have been published. One looked at international data, tracking the suicide rates of 27 countries over the past 20 years, from before the time antidepressant medication was introduced to after. "We saw a protective effect of people seeking treatment," says Dave Marcotte, a health economist at the University of Maryland-Baltimore County. On a county level, a study that compared prescription rates for antidepressants with suicide rates had similar findings.
But the studies did not focus on children, nor do they answer the most important question: What is the benefit of these drugs compared with the risk for children and teens? While for adults the data showing the benefits tend to be persuasive, for children and adolescents they are less so. "We are not where we can have someone come in with a certain profile and I will know before treatment what the risks are of feeling suicidal and gaining or losing lots of weight, versus having a terrifically positive response to treatment," says David Kupfer, chair of the department of psychiatry at the University of Pittsburgh School of Medicine. "I need to rely on group data, and that doesn't give all the information on benefit and risk."
Promising new research on the way serotonin behaves in the brain may eventually help clinicians figure this question out. In December, researchers from Duke University Medical Center found a mutation in a gene with a protein product that has a lot to do with the synthesis of serotonin. People with depression who carry this abnormal gene also show resistance to treatment with SSRI s.
Last month in the American Journal of Psychiatry, researchers reported one clue to treatment response might also be found in blood platelets. SSRI s work by blocking the serotonin reuptake transporter in the neurons; the transporter acts like a vacuum cleaner, controlling the amount of serotonin in the brain. When it is too aggressive, the brain is deprived of serotonin, which can lead to feeling depressed. As it turns out, blood platelets have serotonin reuptake transporters that are identical to the ones found in the brain, so researchers from the University of Pittsburgh looked at the blood of 23 depressed adolescents who were taking SSRI s. Researchers analyzed the patients' biochemistry before and after treatment and found that those who responded well to drug treatment had platelets that were much less sensitive to serotonin.