Neuropsychiatric adverse drug reactions: passive reports to Health and Welfare Canada's adverse drug reaction database (1965-present).

OBJECTIVE: Since 1965, Health and Welfare Canada has operated an adverse drug reaction (ADR) program. The program accepts spontaneous reports of adverse drug reactions, and maintains an ADR database. The purpose of this article is to summarize the Psychiatric ADRs reported to this database since 1965. The nature of the information prohibits its use in the evaluation of epidemiological hypotheses about the etiology of drug-induced mental disorders. However, in an exploratory sense, the contents of the database may contribute to the development of epidemiological hypotheses about the etiology of drug-induced mental disorders. Of particular interest are areas of apparent contradiction between the contents of the database and the clinical literature.
METHODS: The database was searched for reports of ADRs to a group of drugs which have been frequently implicated in causing psychiatric toxicity. All reports characterized as "psychiatric disorders" were down-loaded from the database for the analysis (n = 1822). The reports were further classified into nine categories according to the type of psychiatric symptoms described.
RESULTS: There were several reports of hallucinations caused by methyldopa, and also several reports of benzodiazepine-induced hallucinations and encephalopathy. These reactions have not been described in the literature. Also, there were few reports of digoxin-induced organic depression, and an absence of reports of organic mania induced by H-2 blockers, despite descriptions of these sorts of reactions in the clinical literature.
CONCLUSIONS: Further research is needed to define the neuropsychiatric toxicity associated with medical drugs. Clinicians must continue to consider the potential role of medications in the etiology of psychiatric symptoms.