[Assessment of mental states at risk of psychotic transition: validation of the French version of the CAARMS]

Abstract

This article aims to present the validation study of the French version of the Comprehensive Assessment of at risk mental states (CAARMS), an interview that seeks to determine whether young adults criteria for at-risk (AR) mental states, or psychosis. We assessed 40 young subjects, 15 were considered as "prodromal" (Prd) and 10 as experiencing a first episode of psychosis (PEP) by our expert clinician at the center - centre d'évaluation des jeunes adultes et adolescents, University Hospital Centre, Paris - and 15 were healthy controls matched for age and sex. When assessed with the CAARMS, 73 % (n=11) of the prodromal subjects reached the criteria for AR mental state, four subjects did not reach the criteria for AR, nor psychosis (P) and 100 % of the PEP reached the criteria for P. The three groups were significantly different on CAARMS total score (P<0.001) and subscores ; Prd subjects had intermediate scores between PEP (P<0.001) and controls (P<0.001) scores, PEP showing the highest scores. Post-hoc analysis showed that Prd significantly differed from Controls on each subscale (P<0.001) and that Prd differed from PEP on the "positive symptoms" subscale (P<0.001), as well as on "behavioural change" (P=0.021), owing to difference on the item "impaired role function". We used the brief psychiatric rating scale 24 items with anchor (BPRS24-EA) in addition to with the CAARMS, the AR group showed intermediate scores between controls and P subjects. Total scores of both scales were correlated (r=0.408 ; P=0.043) and the BPRS24-EA "positive symptoms" score was correlated with CAARMS' scores on the "Positive symptoms" subscale (r=0.456, P=0.022), "emotional disturbance" (r=0.506, P=0.01), and "behavioural change" (r=0.666 P=0.001). We found no correlation between BPRS negative and depression subscales and any of the CAARMS' subscales. When looking at its reliability, reliability coefficients (Cronbach's alpha) showed excellent reliability for "positive symptoms", "emotional disturbance", "behavioural change" and "general psychopathology" (respectively r=0.82, 0.75, 0.78, 0.84, 0.83) and moderate reliability for "cognitive change", "negative symptoms" and "motor/physical change" (respectively r=0.39, 0.59, 0.43). Overall, analysis of the results of construct validity, concurrent validity and reliability of the CAARMS indicates that the French version is valid and reliable. It is now available to develop and implement early detection programs in French speaking countries.

Keywords: Access to care; Accès aux soins; Diagnostic précoce; Early diagnosis; Prodromes; Psychose; Psychosis; Schizophrenia; Schizophrénie.