Neuropsychological performance at the age of 13 years and adult schizophreniform disorder: prospective birth cohort study.

We examined neuropsychological functioning at age 13 years in adolescents who later developed schizophreniform disorder, compared with healthy controls and with adolescents diagnosed as having had a manic episode or depression or anxiety disorder. Participants were from an unselected birth cohort. Attentional, executive and motor impairments at age 13 were found in those who later fulfilled diagnostic criteria for schizophreniform disorder, suggesting that these impairments may be the earliest emerging neuropsychological impairments in schizophrenia-related disorders.