(HealthDay News) — For patients with unipolar depression, the risk of subsequent mania/bipolar disorder is increased in association with antidepressant treatment, according to a study published online December 14 in BMJ Open.
Rashmi Patel, BM, BCh, from King’s College London, and colleagues examined the correlation between antidepressant therapy and later onset of mania/bipolar disorder in a retrospective cohort study. Data were reviewed for 21 012 adults presenting to the South London and Maudsley National Health Service Trust with unipolar depression between April 1, 2006, and March 31, 2013.
The researchers found that the overall incidence rate of mania/bipolar disorder was 10.9/1,000 person-years. The peak incidence of mania/bipolar disorder was observed in patients aged 26 to 35 years (12.3 per 1,000 person-years). There was a correlation between prior antidepressant treatment with increased incidence of mania/bipolar disorder, varying from 13.1 to 19.1 per 1,000 person-years. Significant correlations were seen for selective serotonin reuptake inhibitors and venlafaxine (hazard ratios, 1.34 and 1.35, respectively).
“In people with unipolar depression, antidepressant treatment is associated with an increased risk of subsequent mania/bipolar disorder,” the authors write. “These findings highlight the importance of considering risk factors for mania when treating people with depression.”
Several authors disclosed financial ties to the pharmaceutical industry.