The Dysbindin Gene (DTNBP1) Is Associated with Methamphetamine Psychosis

Background The dysbindin (DTNBP1 [dystrobrevin-binding protein 1]) gene has repeatedly been shown to be associated with schizophrenia across diverse populations. One study also showed that risk haplotypes were shared with a bipolar disorder subgroup with psychotic episodes, but not with all cases. DTNBP1 may confer susceptibility to psychotic symptoms in various psychiatric disorders besides schizophrenia. Methods Methamphetamine psychosis, the psychotic symptoms of which are close to those observed in schizophrenia, was investigated through a case (n = 197)–control (n = 243) association analyses of DTNBP1. Results DTNBP1 showed significant associations with methamphetamine psychosis at polymorphisms of P1635 (rs3213207, p = .00003) and SNPA (rs2619538, p = .049) and the three-locus haplotype of P1655 (rs2619539)-P1635-SNPA (permutation p = .0005). The C-A-A haplotype, which was identical to the protective haplotype previously reported for schizophrenia and psychotic bipolar disorders, was a protective factor (p = .0013, odds ratio [OR] = .62, 95% confidence interval [CI] .51–.77) for methamphetamine psychosis. The C-G-T haplotype was a risk for methamphetamine psychosis (p = .0012, OR = 14.9, 95% CI 3.5–64.2). Conclusions Our genetic evidence suggests that DTNBP1 is involved in psychotic liability not only for schizophrenia but also for other psychotic disorders, including substance-induced psychosis.