Symptomatic overlap of cocaine intoxication and acute schizophrenia at emergency presentation

Cocaine intoxication and acute abstinence alter brain dopaminergic functioning, resulting in behavioral changes closely mimicking the positive and negative symptoms of schizophrenia. In emergency room settings, recent cocaine abuse can be mistaken for schizophrenia and may cause inappropriate diagnosis and in some instances medical mismanagement. Schizophrenia patients presenting with recent cocaine abuse may also present with significant diagnostic and treatment dilemmas. This study attempts to distinguish between cocaine and schizophrenic psychosis by examining patients who present with both recent cocaine abuse and acute schizophrenia (CA+SZ), cocaine intoxication without schizophrenic illness (CA), and acute schizophrenia with no comorbid substance abuse (SZ) within the first 24 hours after arrival at the Bellevue psychiatric emergency service. Clinical assessment included the Brief Psychiatric Rating Scale, the Schedule for the Assessment of Positive Symptoms, and the Schedule for the Assessment of Negative Symptoms. Both cocaine abusing groups were required to have positive urine toxicology screens for inclusion in the study. Multivariate analysis of variance showed the CA+SZ patients present with a clinical profile that overlaps with CA patients on mood and negative symptom dimensions and overlaps with SZ patients on most positive symptoms. CA+SZ patients differed from both groups, however, by presenting with significantly more hallucinatory experiences than cocaine abusing or schizophrenia patient counterparts. Despite considerable overlap, each group of patients presented with a discernible cross-sectional symptom pattern.