Suicidal Risks Comparable for Different Antidepressant Agents

April 15, 2010 — When initiating antidepressant therapy in children and adolescents, there appears to be no clinically meaningful variation in the risk for suicidal acts by antidepressant agent within the class of serotonin reuptake inhibitors (SSRIs) or among different classes of antidepressant.

These findings are from a 9-year cohort study published online April 12 and appearing in the May issue of Pediatrics.

"Our finding of equal event rates among antidepressant agents supports the decision of the Food and Drug Administration to include all antidepressants in the black box warning regarding potentially increased suicidality risk for children and adolescents beginning use of antidepressants," Sebastian Schneeweiss, MD, ScD, of Harvard Medical School in Boston, Massachusetts, and colleagues note in their report.

"The results of the new study are not surprising," Mark Olfson, MD, MPH, professor of clinical psychiatry at Columbia University/New York State Psychiatric Institute in New York City, who was not involved in the study, told Medscape Psychiatry.

"Previous research suggests that at most there are only slight differences in safety risk among different types of antidepressants. However, the new study extends our understanding of this important issue by including a far wider range of antidepressants than were included in earlier studies. The results support the concept that large safety differences do not exist among the most commonly prescribed antidepressants," Dr. Olfson said.

The study population comprised all British Columbia residents, 10 to 18 years old, who started taking an antidepressant between January 1, 1997, and December 31, 2005 (n = 20,906). Eighty percent of the study population (n = 16,774) had no previous antidepressant use.

During the first 12 months of treatment, the researchers identified 266 attempted and 3 completed suicides — an event rate of 27.04 suicidal acts per 1000 person-years (95% confidence interval [CI], 23.9 – 30.5 suicidal acts per 1000 person-years).

They failed to see any significant differences in rate ratios (RRs) in analyses comparing fluoxetine with citalopram (RR, 0.97; 95% CI, 0.54 – 1.76), fluvoxamine (RR, 1.05; 95% CI, 0.46 – 2.43), paroxetine (RR, 0.80; 95% CI, 0.47 – 1.37), and sertraline (RR, 1.02; 95% CI, 0.56 – 1.84).

"These findings suggest that paroxetine is not significantly more or less safe than other commonly prescribed antidepressants," Dr. Olfson commented.

Tricyclic antidepressants showed risks similar to those of SSRIs (RR, 0.92; 95% CI, 0.43 – 2.00). Because of the small number of subjects receiving monoamine oxidase inhibitors, the researchers did not attempt to compare the risk of suicidal acts between these agents and SSRIs.

On the basis of the current findings, Dr. Olfson told Medscape Psychiatry, "Once the decision has been made to start an antidepressant, safety considerations should not weigh heavily in antidepressant choice. Instead, the clinical focus should shift to a consideration of antidepressant efficacy and tolerability."

He also noted that "despite the best evidence to the contrary, some physicians remain skeptical that antidepressants increase risk of suicidality in their child and adolescent patients. The new study does not address these lingering doubts."

Dr. Schneeweiss and colleagues "went to great lengths to level the playing field among antidepressant groups. Nevertheless, they cannot exclude the possibility that one group has greater unmeasured background risk than another group and that this unmeasured difference conceals real differences in the safety of the individual antidepressants," Dr. Olfson emphasized.

Pediatrics. 2010;125:876-888.