Psychotism and its dimensions in primary care. Associations with patient's background and manic and depressive symptoms. Results of the RADEP study

Abstract

Dimensions of psychotism have mainly been studied in clinical samples. We studied psychotism, its dimensions and their associations, in a primary care sample. In all, 1199 primary care patients over 18 years of age filled in a questionnaire including lists of psychotic (the Composite International Diagnostic Interview, CIDI), depressive (the Depression Scale, DEPS) and manic (the Mood Disorder Questionnaire, MDQ) symptoms. Psychotic symptoms were factored, and variance in factor scores was explained by patients’ background and by depressive and manic symptoms. In the principal component solution, the first factor explained 22% of the total variance in psychotic (CIDI) symptoms and was named global psychotism. Varimax rotation produced seven interpretable dimensions: Schneiderian (9.7% of variance), passivity (8.9%), hallucinatory (8.5%), paranoid (7.7%), infidelity (7.6%), somatic (7.6%) and reference experiences (5.9%). Together they explained 52% of the total variance of CIDI symptoms. Global psychotism (P=0.000), as well as hallucinatory (P=0.003), paranoid (P=0.000) and infidelity (P=0.000) experiences associated inversely with age. Otherwise, patients’ background associated differently with global psychotism and with factor dimensions in CIDI symptoms. Manic symptoms associated with global psychotism and with all CIDI dimensions, whereas depressive symptoms associated with global psychotism, passivity, paranoid and infidelity experiences. Psychotism is composed of a global factor and of independent dimensions, and is more prevalent in young people. Independently of patients’ background, manic widely and depressive symptoms less widely associate with occurrence of psychotism.