Advanced statistical analysis of epidemiological studies

Sample from register data.
• All patients identified in DCPR before 1 January 1994 with a
bipolar (“manic”) diagnosis at first discharge.
• Restrict attention to patients younger than 52 years at diagnosis,
1307 men and 1655 women.
• Followed to 31 December 1999 w.r.t. later psychiatric
admissions, death, diagnosis of schizophrenia or emigration.
Purpose of study: Evaluate theory of “sensitization” (or “kindling”).
According to this theory, mood episodes themselves stress the brain
so that its sensitivity to biologic and psychosocial stressors increases.
This leads to shorter and shorter intervals between successive
episodes, e.g. (Post, 1992, Amer. J. Psych.)
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