[Psychometric properties of the French versions of the Cognitive Slippage Scale and Schizotypal Ambivalence Scale in 340 subjects].

AIMS: The aim of this article is firstly to present the French translations of the Cognitive Slippage (Miers and Raulin, 1987) and the Schizotypal Ambivalence Scales (Raulin, 1986), and secondly to determine their psychometric properties in different samples of non-clinical and clinical subjects.

BACKGROUND: Chapman et al. have developed trait-oriented scales based on Meehl's manual of schizotypy, such as the Physical and Social Anhedonia Scales, the Perceptual Aberration Scale, the Magical Ideation Scale, the Impulsive Nonconformity Scale, the Cognitive Slippage Scale (CSS), and the Schizotypal Ambivalence Scale (SAS). The Chapman scales of psychosis proneness are the most internationally used instruments for the assessment of schizotypy and some of them such as the Cognitive Slippage and Schizotypal Ambivalence Scales were still not available in French.

METHOD: The study was conducted in three different samples: the non-clinical sample (n=158) comprised firstly 128 university students (113 females, 15 males) with a mean age of 24.67 years (sd=5.18) and secondly 30 healthy subjects (12 males, 18 females) with a mean age of 33.26 years (sd=7.35); the clinical sample (n=167) comprised firstly 106 psychiatric patients hospitalized in a general hospital (73 males, 33 females) with a mean age of 38.35 years (sd=11.60) and 61 (35 males, 26 females) in or outpatients of a psychiatric department with a mean age of 37.75 years (sd=10.72); 15 schizotypal university students presenting high score of the Revised Social Anhedonia Scale (1 male, 14 females) with a mean age of 21.26 years (sd=1.1). Using the ICD-10, the diagnoses for the general hospital sample were neurotic or anxious disorders (47%) and depressive disorders (24%). For the psychiatric department sample, the diagnoses were schizophrenic disorders (29%), mood disorders (16%), neurotic disorders (18%) and personality disorders (15%). The internal consistency was determined by the Kuder-Richardson coefficient (KR 20) (CSS: KR 20=0.85 in the university sample; 0.89 in the general hospital sample; 0.87 in the psychiatric department sample; SAS: KR 20=0.79 in the university sample; 0.82 in the general hospital sample; 0.85 in the psychiatric department sample).

RESULTS: The mean of the correlations between each item and the total score was calculated (CSS: 0.41 in the university sample; 0.44 in the general hospital sample; SAS: 0.46 in the university sample; 0.49 in the general hospital sample). The discriminant validity was studied by a Student's t test showing that the schizotypal university students had significant higher scores on the CSS and SAS than the healthy university students. The reliability was explored using a test-retest in the 30 healthy subjects. The subjects filled out the scales three months after the first testing. The intraclass coefficients were 0.81. Finally, the cutoff scores were calculated following the procedure described by Chapman et al. (score higher than two standard deviations above the mean of the university sample). The values for the CSS and SAS were respectively 15 and 12 for males and females.