Stress reactivity in bipolar patients and its relation to prior history of disorder

Two questions were posed: Does stress precipitate episodes of bipolar I disorder, and does sensitivity to stress differ in episodes later in the course of illness compared to early ones?

Fifty-two patients with bipolar I disorder were followed longitudinally for up to 2 years; clinical course was monitored, and interview assessments of life events were made every 3 months.

The patients who had episodes of illness during follow-up had experienced significantly more severe stressors and more total stress in the preceding 6 months, and more total stress in the preceding 3 months, than those without episodes. Inconsistent with Post's stress "sensitization" hypothesis, patients with more prior episodes were more likely to have episodes following major stressors, and they relapsed more rapidly.

Stressors may precipitate episodes of bipolar illness, especially for patients with more prior episodes. Different versions of the stress sensitization model remain to be tested.