Weight gain with atypical antipsychotics such as clozapine has been hypothesized to have a multifactorial genesis. Beside changes in neurotransmitter systems caused by antipsychotic-induced receptor blockade, hormonal changes and other neuroleptic side-effects (sedation, reduced activity, reduced basal metabolic rate, dry mouth) are also discussed. Our unique case report of a patient with comorbid galactosemia and schizophrenia is an interesting example of weight gain being a positive side-effect of clozapine, not necessarily associated with increased appetite and higher caloric intake.
