Screening for psychosis risk among adolescents in Child and Adolescent Mental Health Services: a description of the first step with the 16-item version of the Prodromal Questionnaire (PQ-16)

Aim: Although the 16-item version of the Prodromal Questionnaire (PQ-16) is used as a screener in the early detection of psychosis risk, little is known about PQ-16 scores among adolescents referred to the Child and Adolescent Mental Health Services. We assessed such scores in adolescents referred to these services in the Netherlands, and also their associations with age, gender, diagnosis and level of functioning.

Methods: The PQ-16 was added to regular intake procedures.

Results: The PQ-16 was completed by 176 adolescents (mean age 14.58 years; standard deviation = 1.50; 55.1% females), 34.7% of whom scored above the current cut-off score of ≥6 items. Positive item scores with the highest odds ratio for scoring above the cut-off were related to tasting or smelling things, seeing things and hearing thoughts out aloud. There were no age-, gender- or disorder-related differences in total scores on the PQ-16. Lower Global Assessment of Functioning scores were associated with higher total scores on the PQ-16.

Conclusions: The PQ-16 is easy to implement in routine assessment and can be useful to bring up potential psychotic symptoms for further exploration in an early stage, especially in adolescents with low Global Assessment of Functioning scores. The PQ-16 total scores were not confounded by differences in age, gender or disorder. Future research should investigate the true nature of PQ-16 items and whether the item scores and cut-off scores of the PQ-16 in adolescence have any predictive value regarding the development of an ultra high-risk status, a psychotic disorder or other mental disorders.