Johnson's team studied 59 adults diagnosed with bipolar disorder, most of whom entered the study during an episode of either mania or depression. The findings held regardless of whether participants received drug treatment. A related investigation, published in the same journal issue, indicates that some people with manic depression prove more psychologically vulnerable to stressful events than others do. Most participants in these three groups weren't receiving any mental-health treatment. Over a 4-month period, depression increased only among those individuals with either bipolar disorder or major depression who displayed negative thinking styles and reported a death in the family, divorce, or other stressful experience.
Negative thinkers blame themselves for personal misfortunes and consider themselves incompetent.
Such a mix of negative thinking and stressful events also heralded rises in manic symptoms for volunteers with bipolar disorder, the researchers say. It's possible that in bipolar disorder, manic episodes serve as a psychological defense or counterpunch against a relentless propensity for sinking into depression, Reilly-Harrington and her colleagues propose. Psychoanalytically inclined clinicians have long articulated this position. This view is supported by a 1998 study directed by psychologist Susan Malkoff-Schwartz of the University of Pittsburgh School of Medicine. Her group found that bipolar patients tended to become manic within about 2 months of having their daily routines rearranged, even temporarily.