Stressful events predict mood disorders in children of bipolar parents
Sept. 1, 2004
Stressful lifetime events appear to increase the risk of mood disorders developing in adolescents born to parents with bipolar disorder, suggest study findings that highlight the effect is independent of genetic vulnerability.
Manon Hillegers (Altrecht Institute for Mental Health Care, Utrecht, The Netherlands) and colleagues studied the effect of life events on the development of mood disorders in 140 Dutch adolescents who had parents with bipolar disorder.
In all, 38 (27%) of the children developed a mood disorder during follow-up, at a median age of 14 years.
The results, published in the British Journal of Psychiatry, showed that adolescents who developed mood disorders had experienced higher levels of stressful life events than those that did not develop such conditions.
Indeed, the life event load was significantly associated with approximately a 10% increase in the risk of mood disorder per unit life event load.
Moreover, although familial vulnerability was itself strongly associated with the development of mood disorders, adjustment for this variable had little effect on the relationship between stressful life events and mood disorder development.
"Both [factors] had independent effects on risk of mood disorders," the researchers write.
They also found that the impact of stressful life events principally accumulates, but at the same time gradually decays, as time goes by, at a rate of 25% per year.
"This suggests that the effects of stressful life events do not simply add up or rapidly extinguish but, in a gradually fading fashion carry over into the future risk of an episode of mood disorder," Hillegers and team comment.
"What drives the decay is not known, it might result from coping strategies or the effect of neutralizing life events."
Br J Psychiatry 2004; 185: 97-101