Risk and Prognostic Factors
Genetic and physiological. The risk of bipolar II disorder  tends to be highest among rel-
atives of individuals with bipolar II disorder, as opposed to individuals with bipolar I dis-
order or major depressive disorder. There ma y be genetic factors influencing the age at
onset for bipolar disorders.
Course modifiers. A rapid-cycling pattern is associated  with a poorer prognosis. Return
to previous level of social fu nction for individuals with bipolar II disorder is more likely
for individuals of younger age and with less severe depression, sugge sting adverse effects
of prolonged illness on recovery. More education, fewer ye ars of illness, and being mar-
ried are independently associated with functi onal recovery in individuals with bipolar
disorder, even after diagnostic  type (I vs. II), current depressive symptoms, and presence
of psychiatric comorbidity are taken into account.
Gender-Related Diagnostic Issues
Whereas the gender ratio for bipolar I disorder is equal, findings on gender differences in
bipolar II disorder are mixed, differing by type of sample (i.e., registry, community, or
clinical) and country of origin. There is little to  no evidence of bipolar gender differences,
whereas some, but not all, clinical samples su ggest that bipolar II disorder is more com-
mon in females than in males, which may refl ect gender differences in treatment seeking
or other factors. 
Patterns of illness and comorbidity, however,  seem to differ by gender, with females
being more likely than males to report hypomania with mixed depressive features and a
rapid-cycling course. Childbirth may be a spec ific trigger for a hypomanic episode, which
can occur in 10%–20% of females in nonclinical populations and most typically in the early