154 Bipolar and Related Disorders
are often characterized by prominent energy, hypersomnia, overeating, weight
gain, and a craving for carbohydrates. It is unclear whether a seasonal pattern is
more likely in recurrent major depressive di sorder or in bipolar disorders. However,
within the bipolar disorders group, a seasonal pattern appears to be more likely in
bipolar II disorder than in bipolar I disorder. In some individuals, the onset of manic
or hypomanic episodes may also be linked to a particular season.
The prevalence of winter-type seasonal pattern appears to vary with latitude,
age, and sex. Prevalence increases with higher  latitudes. Age is also a strong pre-
dictor of seasonality, with younger persons at higher risk for winter depressive epi-
sodes.
Specify if:
In partial remission: Symptoms of the immediately previous manic, hypomanic, or
depressive episode are present, but full criteria are not met, or there is a period lasting
less than 2 months without any significant symptoms of a manic, hypomanic, or major
depressive episode following the end of such an episode.
In full remission:  During the past 2 months, no significant signs or symptoms of the
disturbance were present.
Specify current severity: 
Severity is based on the number of criterion symptoms, the severity of those symptoms,
and the degree of functional disability.
Mild:  Few, if any, symptoms in excess of those required to meet the diagnostic criteria
are present, the intensity of the symptoms is distressing but manageable, and the
symptoms result in minor impairment in social or occupational functioning.
Moderate: The number of symptoms, intensity of symptoms, and/or functional impair-
ment are between those specified for “mild” and “severe.”