Psychotic‐like experiences and multimorbid psychopathology: The relationship between the 16‐item prodromal questionnaire and DSM‐IV classifications in a help‐seeking population

Abstract

AbstractAimIdentifying multimorbid psychopathology is necessary to offer more adequate treatment and ultimately reduce the prevalence of persistent mental illnesses. Psychotic symptoms are increasingly seen as a transdiagnostic indicator of multimorbidity, severity and complexity of non‐psychotic psychopathology. This study aims to investigate whether psychotic‐like experiences and subclinical psychotic symptoms as measured by the 16‐item Prodromal Questionnaire are also associated with multimorbid psychopathology.MethodsParticipants were help‐seeking individuals from outpatient mental healthcare settings and intensive home‐treatment teams, aged 17–35. Assessment included the 16‐item Prodromal Questionnaire to measure psychotic‐like experiences, the Structured Clinical Interview for DSM‐IV Axis I, and three sections of the Structured Clinical Interview for DSM‐IV Axis II Disorders to determine DSM‐IV‐TR classifications. The final sample comprised of 160 participants who scored above a cutoff of 6 items on the 16‐item Prodromal Questionnaire (HIGH‐score) and 60 participants who scored below cutoff (LOW‐score). A Poisson Regression was executed to determine the association between the PQ‐16 and DSM‐IV‐TR classifications.ResultsThe HIGH‐score group had a mean of 2.76 multimorbid disorders (range 0–7), while the LOW‐score group had a mean of 1.45 disorders (range 0–3). Participants with four to seven disorders scored high on the 16‐item Prodromal Questionnaire.ConclusionsOur results suggest that psychotic‐like experiences are associated with multimorbidity and severity of psychopathology. Screening for psychotic‐like experiences via the PQ‐16 in a help‐seeking population may help prevent under‐diagnosis and under‐treatment of comorbid psychopathology.