Poor premorbid school performance is associated with later cigarette smoking among schizophrenia patients.

Schizophrenia patients who smoke have been postulated to have genetically mediated dysfunctional nicotinic neurotransmission. We hypothesized that this nicotinic dysfunction would manifest as poorer school performance in adolescence, before the onset of illness, in smoking compared with non-smoking schizophrenia patients. Over a 31-year follow-up period, 100 (65 men) cohort members of the Northern Finland 1966 Birth Cohort were hospitalized and diagnosed with DSM-III-R schizophrenia. The information on school performance was obtained at the end of compulsory schooling at age 16 years. The information on smoking habits was gathered from a questionnaire mailed to cohort members at the age of 31 years. Compared with non-smoking schizophrenia patients, schizophrenia patients who smoked in adulthood had lower overall mean grades, lower mean grades in combined mathematical subjects, and lower grades in music. Poor school performance might represent premorbid nicotinergic dysfunction associated with cognitive deficits in future smokers among schizophrenia patients compared with those who remained non-smokers.