A new study by the Harvard School of Public Health found that high doses of antidepressants in teens and young adults correlate to marked increases in self-harm.
The study, released Monday, examined 162,625 subjects between ages 10 and 64 for 12 years. For subjects 24 years and younger, higher-than-average doses of antidepressants doubled the rate of suicidal behavior.
This new study corresponds with past research indicating that selective serotonin reuptake inhibitors (SSRIs), the most common type of antidepressant, significantly increase the risk of suicidal behavior in teens and young adults.
A 2004 review by the U.S. Food and Drug Administration (FDA) also found that antidepressants double the rate of suicidiality in those between ages 18 and 25.
Authors of the Harvard study advised caution in prescribing new patients with antidepressants.
“Considered in light of recent meta-analyses concluding that the efficacy of antidepressant therapy for youth seems to be modest, and separate evidence that dose is generally unrelated to the therapeutic efficacy of antidepressants, our findings offer clinicians an additional incentive to avoid initiating pharmacotherapy at high-therapeutic doses and to monitor all patients starting antidepressants, especially youth.”
The new study did not examine why antidepressants can lead to an increase is self-harm behavior, and in fact, not much research exists on the subject.
However, one theory points towards some patients’ brains being resistant to SSRIs, causing a reversal effect. A 2010 study by Columbia University found that half of patients taking antidepressants were not responding to treatment. The study indicated that serotonin on these patients may lead to a negative reaction. Treatment was found to decrease the brain’s serotonin production.
Lead researcher Dr. Rene Hen stated that for millions of patients, “the more antidepressants try to increase serotonin production, the less serotonin (they) actually produce.”
While the Harvard study isn’t the first of its kind, it shed new light on the possible correlation between dosage and the risk of suicidal behavior. This increase was not found in subjects of the same age who received modal, or average, doses and those over 24.