Life events may worsen bipolar I disorder course
medwireNews: A study suggests that negative life events may trigger depressive episodes in patients with bipolar I disorder.
However, in contrast to previous research, life events did not appear to trigger manic episodes, report Benedikt Amann (FIDMAG Research Foundation Germanes Hospitaláries, Barcelona, Spain) and study co-authors.
Life events were common among the 222 patients in the study, with 62.2% having at least one event within the 6 months before the index mood episode and 49.5% having at least one in the 6 months after the episode.
The researchers found a weak but statistically significant correlation between the number of life events before and after the index mood episode.
“This may imply that suffering from current life events increases the risk of life events in the future, in the sense that past life events ‘cause’ new life events”, they write in the Journal of Affective Disorders. “Alternatively, it is also possible that underlying factors, such as co-morbid personality disorders, continuously increase the risk of life events.”
The number of life events before the index episode had no effect on the risk of patients relapsing. However, each additional life event after this episode increased the risk of patients having a depressive relapse by 33%.
This suggests that life events have an acute effect on the risk of relapse, and also implies that the events themselves, rather than underlying factors such as comorbidities, may contribute to patients relapsing, say the researchers.
On further analysis, the team found the association to be limited to the 126 bipolar I disorder patients, in whom each additional event raised the risk by 64%. Life events did not raise the risk of manic episodes in bipolar I disorder patients and did not raise the risk of depressive relapse in the 96 patients with bipolar II disorder. Amann et al did not assess hypomanic episodes due to the difficulty of defining them and because they often go unreported.
Nevertheless, they highlight the important effect of life events in patients with bipolar I disorder, which “clearly worsened the course of the disease by triggering more depressive episodes.”
Negative life events, such as loss of employment, relationship, or close friend or family member raised the risk of depressive relapse, but so did positive events such as a new relationship or job.
“[O]ur findings underline the importance of detection but especially of treatment of life events in bipolar disorder”, says the team.
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By Eleanor McDermid, Senior medwireNews Reporter