Introduction. The auditory hallucinations associated with schizophrenia are phenomenologically diverse. “External” hallucinations classically have been considered to reflect more severe psychopathology than “internal” hallucinations, but empirical support has been equivocal.

Methods. We examined associations of “internal” versus “external” hallucinations with (1) other characteristics of the hallucinations, (2) severity of other symptoms and (3) course of illness variables, in a sample of 97 stable outpatients with schizophrenia or schizoaffective disorder who experienced auditory hallucinations.

Results. Patients with internal hallucinations did not differ from those with external hallucinations on severity of other symptoms. However, they reported their hallucinations to be more emotionally negative, distressing and long-lasting, less controllable and less likely to remit over time. They also were more likely to experience voices commenting, conversing or commanding. However, they also were more likely to have insight into the self-generated nature of their voices. Patients with internal hallucinations were not older, but had a later age of illness onset.

Conclusions. Differences in characteristics of auditory hallucinations are associated with differences in other characteristics of the disorder, and hence may be relevant to identifying subgroups of patients that are more homogeneous with respect to their underlying disease processes.