Two polymorphisms in the 5-HTT gene (a 44 bp insertion/deletion in the promoter region and the functional polymorphism rs25531) were genotyped in a sample of 147 drug-naïve patients experiencing a first episode of a non-affective psychosis.
We report here studies of the effects of the 5-HTTLPR polymorphism on the probability that an individual will develop mental maladaptation in 224 close relatives of patients with severe chronic mental disorders - schizophrenia and schizoaffective and affective psychoses.