OBJECTIVE: This study examined patients' attitudes toward their hallucinations by assessing their beliefs about the purposes served by hallucinations and the adverse effects of hallucinations. It also investigated whether these attitudes were related to characteristics of the hallucinations or of the patients, whether the attitudes changed after treatment, and whether attitudes before treatment predicted the presence or absence of hallucinations after treatment. METHOD: Fifty hallucinating psychiatric inpatients were given semistructured interviews shortly after admission to the hospital and again shortly before discharge. The interviews elicited detailed descriptions of 12 phenomenologic characteristics of hallucinations and 11 attitude variables. RESULTS: The majority of subjects reported some positive effects of hallucinations. The presence of olfactory hallucinations and the ability to predict hallucinations were significantly related to valuing hallucinations. Attitudes usually did not change with treatment; when they did change they usually became more positive. Subjects who valued hallucinations more before treatment were significantly more likely to be hallucinating after treatment. CONCLUSIONS: The findings are consistent with the idea that psychological factors contribute to the expression of hallucinations. Assessing adaptive functions of hallucinations may predict whether hallucinations will respond to treatment and identify fruitful areas for psychosocial intervention.Abstract Teaser