Validation of the Hamilton Program for Schizophrenia Voices Questionnaire: associations with emotional distress and wellbeing and invariance across diagnosis and sex

Background: Voice-hearing is a transdiagnostic experience with an evident negative impact on patients. Good quality measurement is needed to further elucidate the nature, impact and treatment of voice-hearing experiences across patient groups. The Hamilton Program for Schizophrenia Voices Questionnaire (HPSVQ) is a brief self-report measure which requires further psychometric evaluation. Methods: Using data from a transdiagnostic sample of 401 adult UK patients, the fit of a conceptual HPSVQ measurement model, proposing a separation between physical and emotional voice-hearing characteristics, was tested. A structural model was examined to test associations between voice-hearing, general emotional distress (depression, anxiety, stress) and wellbeing. The invariance of model parameters was examined across diagnosis and sex. Results: The final measurement model comprised two factors named ‘voice severity’ and ‘voice-related distress’. The former comprised mainly physical voice characteristics and the latter mainly distress and other negative impacts. Structural model results supported voice-related distress as mediating the associations between voice severity and emotional distress and wellbeing. Model parameters were invariant across psychosis versus non-psychosis diagnosis and partially invariant across sex; with females experiencing more severe and distressing voices and a more direct association between voice severity and general anxiety. Conclusions: The HPSVQ is a useful self-report measure of voice-hearing with some scope for further exploration and refinement. Voice-related distress appears a key mechanism by which voice severity predicts general distress and wellbeing. Whilst our data broadly support interventions targeting voice-related distress for all patients, females may benefit from learning to respond to voices in a less resistant mannerespecially from interventions targeting voice severity and strategies for responding.