In some people, taking an antidepressant may kick off an episode of hypomania, an expansive mood characterized by mild elation, talkativeness, increased productivity, and sometimes risky behaviors. Irritability is another feature. Hypomania has its seductive side, but the downside is that, in people who have bipolar disorder, it can progress to mania, an over-the-top 'high' that can degenerate into destructive behaviors and sometimes hospitalization.

People with bipolar disorder cycle through bouts of depression and manic behaviors, interspersed with normal moods. The depressive phases occur more often, tend to last longer, and are experienced more negatively then the manic ones. Consequently, an individual with bipolar disorder may not seek help until depressive symptoms hold sway. As a result, she or he may be misdiagnosed as having classic depression and be inappropriately treated with antidepressants. Bipolar disorder requires a range of treatments, including mood-stabilizing drugs and therapy with a mental health professional. This is another reason why clinicians must keep close track of anyone for whom they've prescribed antidepressants, and likewise, why people taking these drugs should report any unusual symptoms or irritability.

Source: Harvard Women's Health Watch June 2004