The psychopathology inventory for mentally retarded adults: factor structure and comparisons between subjects with or without dual diagnosis.

Whether the Psychopathology Inventory for Mentally Retarded Adults (PIMRA) could detect specific psychopathological disorders was investigated in 652 subjects with different levels of mental retardation living in the community or in residential facilities. An exploratory factor analysis was carried out to check the scale organization of PIMRA. The Anxiety, Adjustment Disorder, Somatoform Disorder, and Soundness Scales were confirmed by 4 corresponding factors; the Psychosexual Disorder Scale was replaced by a factor specific to gender identity problems, and the Schizophrenia Scale by two factors concerning isolation and bizarre behaviors, respectively. The items of the Depression Scale were distributed over the three factors concerning anxiety, adjustment, and psychosomatic disorders, while the items of the Personality Disorder Scale were scattered over almost all the factors. Moreover, 55 subjects with anxiety disorders and 49 with depression were compared to 50 control subjects of the same age, intelligence level, and gender ratio but without dual diagnosis and obtained significantly higher factorial scores both on the overall scale and on the factors specifically related to their disorders. PIMRA has been found to show good construct validity. These results could be considered particularly valid as they were obtained from a large sample comprising different levels of mental retardation and thus showing all possible psychopathological behaviors.