Background: Cocaine can induce transient psychotic symptoms. We examined the phenomenology of such cocaine-induced psychosis (CIP) using a modified version of the Scale for Assessment of Positive Symptoms (SAPS), a well-validated instrument for the assessment of schizophrenic psychosis.
Methods: We developed a new instrument, the Scale for Assessment of Positive Symptoms for Cocaine-Induced Psychosis (SAPS-CIP), based on the well-validated SAPS. We interviewed 243 unrelated cocaine-dependent adults using both the SAPS-CIP and an instrument for the identification of cocaine-induced paranoia, the Cocaine Experience Questionnaire (CEQ).
Results: One hundred and eighty-one (75%) of the subjects endorsed CIP using the CEQ. With the SAPS-CIP, hallucination (HAL) and delusion (DEL) scores correlated strongly, and the DEL domain showed excellent concurrent validity with the CEQ. We observed significant positive correlations, respectively, between severity of HAL and DEL, and lifetime number of episodes of cocaine use, and negative correlations with age at onset of cocaine use.
Conclusions: The results suggest that CIP consists of transient delusional and hallucinatory symptoms, which tend to occur together and co-vary in severity. It appears that rating cocaine-induced paranoia alone (e.g., with the CEQ) can identify most subjects experiencing CIP. However, the SAPS-CIP is useful for quantifying the severity of CIP according to operational criteria. Our data provide additional evidence that CIP is a sensitizing response.