Background: Mental health of prisoners, as a high risk group, is of considerable importance. Unfortunately limited data is currently available about psychiatric morbidity of this group in Iran. This study was designed to determine the prevalence of axis I disorders in prisoners and their correlation with the type of offense.

Methods: Using stratified random sampling 351 prisoners from five offense categories (54 from financial, 71 from violent, 74 from nonviolent, 72 from drug related and 80 from immoral acts subgroup) were recruited into the study, and examined by Structured Clinical Interview for DSM-IV.

Results: Eighty- eight percent of the prisoners had experienced at least one axis I disorder throughout their lives, and 46.9% met the criteria for current disorders. Substance related (78%) and mood disorders (48.7%) were the most prevalent of lifetime disorders. However, mood (30.7%) and adjustment (12.6%) disorders had the highest amounts in current diagnoses. The total number of disorders was lowest in the financial subgroup. The drug related subgroup had lower rate of anxiety and higher rate of substance related disorders.

Conclusion: Compared to western studies, the prevalence of axis I disorders in this study is among the highest. The fact that about half of all prisoners at the time of study suffered from at least one axis I disorder shows the emergent need of this group for more mental health care and services.