Certain antidepressants linked to heightened risk of mania and bipolar disorder

http://www.eurekalert.org/pub_releases/2015-12/b-cal121415.php

Public Release: 15-Dec-2015
Certain antidepressants linked to heightened risk of mania and bipolar disorder
Strongest association found for SSRIs and venlafaxine
BMJ

Taking certain antidepressants for depression is linked to a heightened risk of subsequent mania and bipolar disorder, reveals research published in the online journal BMJ Open.

The strongest association seemed to be for serotonin reuptake inhibitors, or SSRIs for short, and the dual action antidepressant venlafaxine, the analysis indicated.

The researchers base their findings on the anonymised medical records of more than 21,000 adults in receipt of treatment for major (unipolar) depression between 2006 and 2013 at a large provider of inpatient and community mental healthcare in London.

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Previous treatment with certain antidepressants was associated with a heightened risk of a subsequent diagnosis of bipolar disorder and/or mania, the yearly risk of which ranged from 1.3% to 1.9% (13.1 to 19.1/1000 patient years).

Further analysis revealed that this heightened risk was particularly associated with treatment with SSRIs and venlafaxine. These drugs were associated with a 34-35% increased risk of being diagnosed with bipolar disorder and/or mania.

These findings held true even after taking account of potentially influential factors.

This is an observational study so no firm conclusions can be drawn about cause and effect, and the researchers point out that their findings may be explained by latent bipolar disorder rather than any effects of drug treatment. Furthermore, they were unable to obtain information on important risk factors.

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