Hospital records of patients seen between 1999 and 2002 were carefully examined. A questionnaire was used to extract relevant information from the case records and clinical diagnosis was made using the ICD-10. Cases that had evidence of pre-existing psychiatric disorder, family history of mental illness or heavy use of alcohol and/or tobacco were excluded. Out of 6,556 patients that were seen for the first time, 849 were drug-related cases and 601 of these were primarily cannabis users. A substantial number (83%) of these were young and presented with severe psychopathologies. About 90% and 47% were diagnosed with psychotic disorders and dependence syndrome, respectively. It is concluded that cannabis use is associated with severe psychopathologies and constituted over 70% of demand for treatment.
Key words: Cannabis, Psychopathologies, Retrospective Study, Nigeria.