Developmental differences in the symptomatology of psychiatric inpatients with and without mild mental retardation.

The symptomatology of psychiatric inpatients with mild mental retardation was compared with that of a matched sample of inpatients without mental retardation. An integration of the developmental position on mental retardation with the developmental approach to adult psychopathology generated the hypotheses that, compared to patients without mental retardation, patients with mild mental retardation would display (a) more symptoms indicative of turning against others and fewer symptoms indicative of turning against the self, (b) more symptoms involving expression in action rather than thought, and (c) psychotic symptom pictures that more frequently involve hallucinations without delusions and infrequently involve delusions alone. All hypotheses were confirmed.