Sexual dimorphisms and prediction of conversion in the NAPLS psychosis prodrome

Abstract

Sex differences in age at onset, symptomatology, clinical course (see Walker et al., 2002) and functional impairment (Thorup et al., 2007) are well documented in psychosis. The general pattern of findings is that males manifest an earlier onset, more severe symptoms and poorer prognosis than females. Limited studies examining individuals at clinical high-risk (CHR) suggest a similar pattern of sexual dimorphism (Holtzman et al., in review; Corcoran et al., 2011). As part of the North American Prodrome Longitudinal Study (NAPLS), the current study prospectively examined sexual dimorphisms in relationships among CHR symptoms, childhood (premorbid) academic and social functioning, baseline social and role functioning, and conversion to psychosis. Subjects included 276 (113F/163M) CHR NAPLS participants (ages 12–36.8years). All measures/criteria were assessed at baseline except conversion status, assessed at 6-month intervals up to 30months. Results show sex differences in baseline social and role functioning (though not in early childhood adjustment) that predate psychosis onset, with sexually dimorphic patterns in relation to prodromal symptoms. Among male (but not female) CHRs, baseline social functioning and positive prodromal symptoms predicted conversion. These findings help elucidate early course of vulnerability for, and maximally sensitive and specific etiological and prediction models of, psychosis conversion. Findings highlight the importance of considering sexually differentiated predictors of longitudinal course and outcome, in the context of emerging risk profiles. This may optimize efforts at early identification and individually tailored preventive interventions targeting different neurobiological markers/systems and/or cognitive-behavioral approaches. We speculate a contemporary, multidimensional model of psychosis risk that posits a role of sexually dimorphic, genetically linked influences that converge with a modulating role of gonadal hormones (see Walder et al., 2012) across a temporally sensitive neurodevelopmental trajectory towards conferring risk.