Objective. The mentally retarded constitute a large proportion of patients treated by the psychiatrist. The specificity of their cognitive functions, problems with verbal communication, as well as neurodevelopmental andpsychosocial characteristics make the process of diagnostic assessment difficult.
Case report. Two patients with drug resistant paranoid schizophrenia are described. A thorough assessment process allowed to change their diagnosis to that of mild mental retardation, with concurrent obsessive-compulsive disorder in one case. A change of the therapeutic strategy resulted in a significant improvement of their condition.
Commentary. On the grounds of the two case reports and a review of the literature the authors analyzed difficulties in psychiatric diagnostics in patients with mental retardation.