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According to the researchers the findings call into question the controversial "black box" warnings placed on the drugs by the Food and Drug Administration (FDA), which say that antidepressant medications pose a small but significantly increased risk of suicidal thoughts and behaviour for children and adolescents.

The University of Pittsburgh researchers found that one in 100 participants in the studies included in the meta-analysis had new-onset suicidal ideation, or suicidal thoughts, while on medication. Even fewer acted on these thoughts, and there were no completed suicides.

The results showed that antidepressants were most effective in treating anxiety, moderately effective for OCD and modestly effective for depression. The number needed to treat (NNT) – a statistical term meaning the number of patients a clinician would need to treat to prevent an adverse outcome in one – was 10 for major depressive disorder, six for OCD and four for anxiety.

The number needed to harm (NNH) – the number of patients who would need to be treated for one to be harmed – was 112 for major depressive disorder, 200 for OCD and 143 for anxiety. These numbers indicate that the increased risk, while not unimportant, is not enough to outweigh the benefits of taking the medications.

For this study, the researchers extracted data on study characteristics, efficacy outcomes and emergent suicidal events from 27 trials of second-generation antidepressants used to treat paediatric major depressive disorder, obsessive compulsive disorder (OCD) and anxiety in children and adolescents under the age of 19. The drugs used were the selective serotonin reuptake inhibitors (SSRIs) nefazodone, venlafaxine and mirtazapine; all of the studies were randomized and placebo-controlled.

MEDICA.de; Source: University of Pittsburgh Schools of the Health Sciences