Fertility and childhood bipolar disorder.

The observation that the diagnosis of bipolar illness is increasingly being made in the young is fascinating and potentially quite instructive. Several potential reasons have been put forward, which may all play a role. These include increased awareness, a cohort effect, changes in the diagnostic criteria, increased use of stimulants and antidepressants unmasking the illness, and others. It is interesting to note that this increase in recognition of bipolar illness in the young comes about one generation after the introduction of lithium as a therapeutic agent in bipolar disorder. We propose that the introduction of lithium may have increased fertility (broadly defined) of bipolar patients allowing for the expression of genetic anticipation by having a second and third generation of offspring that are affected at earlier ages. A similar phenomenon was seen in schizophrenia after the introduction of phenothiazines for the treatment of psychosis. These pharmacologic and social changes may have all conspired to increase reproductive success of bipolar subjects, giving rise to a new generation of bipolar patients with earlier onset and more severe manifestation of their disorder.