Detection of clinical high risk for psychosis in child and adolescent mental health services: Validation of the first step with the French versions of the Prodromal Questionnaire (fPQ-16) and scale of Perceptual and Cognitive Aberrations (fPCA)

Aim: To validate the French versions of the 16-items Prodromal Questionnaire (PQ-16) and the 9-items scale of Perceptual and Cognitive Aberrations (PCA) to facilitate screening of psychosis risk in native French-speaking young individuals referred to Child and Adolescent Mental Health Services.

Method: Participants (N = 87, age range 10-18 years) were diagnosed with a non-psychotic disorder according to the Diagnostic and Statistical Manual of Mental Disorders. The French versions of the PQ-16 and PCA were developed using a forward-backward translation procedure. Psychometric properties were tested including (i) internal validity with Pearson correlations and Cronbach's coefficients, and (ii) external validity by correlations with each other's.

Results: (i) Correlations between fPQ-16 and fPCA total scores and individual items were mostly >.4. Cronbach's coefficients were .80 for the fPQ-16 and .61 for the fPCA. (ii) The fPQ-16 and fPCA total scores were significantly correlated with a large effect size (r_s = 0.66).

Conclusion: The fPQ-16 and the fPCA are psychometrically acceptable instruments for the screening of potential psychotic symptoms in French-speaking children and young adolescents under 18 years old referred to Child and Adolescent Mental Health Services.