~~Seasonal Pattern Specifier~~
American Psychiatric Association (1994). Diagnostic and Statistical Manual of Mental Disorders (4th ed.) Washington, DC: American Psychiatric Assoc.
The specifier with Seasonal Pattern can be applied to the pattern of Major Depressive Episodes in Bipolar I Disorder, Bipolar II Disorder, or Major Depressive Disorder, Recurrent. The essential feature is the onset and remission of Major Depressive Episodes at characteristic times of the year. In most cases, the episodes begin in fall or winter and remit in spring. Less commonly, there may be recurrent summer depressive episodes. This pattern of onset and remission of episodes must have occurred during the last 2 years, without any nonseasonal episodes occuring during this period.(p.389)
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 predictor of seasonality, with younger persons at higher risk for winter depressive episodes. Women comprise 60%-90% of persons with seasonal pattern, but it is unclear whether female gender is a specific risk factor over and above the risk associated with recurrent Major Depressive Disorder.(p.389)
Criteria For Seasonal Pattern Specifier
A. There has been a regular temporal relationship between the onset of Major Depressive Episodes in Bipolar I or Bipolar II
Disorder or Major Depressive Disorder, Recurrent, and a particular time of the year (.e.g. regular appearnace of the Major Depressive Episode in the fall or winter).
Note: Do not include cases in which there is an obvious effect of seasonal-related psychosocial stressors (e.g. regularly being unemployed every winter).
B. Full remissions (or a change from depression to mania or hypomania) also occur at a characteristic time of the year (e.g. depression disappears in the spring)
C. In the last 2 years, two Major Depressive Episodes have occurred that demonstrate the temporal seasonal relationships defined in A and B, and no nonseasonal Major Depressive Episodes have occurred during that same period.
D. Seasonal Major Depressive Episodes (as described above) substantially outnumber the nonseasonal Major Depressive Episodes that may have occurred over the individual's lifetime.