In order to examine the effects of irrelevant distracting information on speech disorder, medicated (n = 13) and unmedicated (n = 18) schizophrenics were compared to a mixed affective sample (n = 15) on the frequencies of linguistic measures of verbal communication disorder. Patients conversed with an interviewer during the presence and absence of irrelevant information inserted into their conversation. Affective patients manifested no distraction-related increase in communication disorder. Schizophrenics on medication manifested a small, but nonsignificant, increase in communication disorders during the concurrent distraction condition. Unmedicated schizophrenics manifested a substantial increase in their communication disorders during distraction. These data suggest that medication reduces the extent to which speech processes in schizophrenia are vulnerable to overload-related deterioration and provide confirmation of the hypothesis that some component of positive thought disorder in schizophrenia is due to medication-responsive attention deficits.