Psychiatric Diagnosis at Prison Admission: Clinical and Sociodemographic Characteristics of Newly Admitted Inmates

Background/Objectives: Individuals entering prison represent a highly vulnerable population with substantial mental health needs. While the prevalence of psychiatric disorders in correctional settings has been widely documented, evidence on the factors associated with a psychiatric diagnosis at prison admission remains limited. This study aimed to characterize the clinical and sociodemographic profile of newly admitted inmates and to identify independent factors associated with a psychiatric morbidity at prison entry. Methods: This retrospective cross-sectional study included individuals newly admitted to the Correctional Center in Southern Italy between 2023 and 2025. Routinely collected sociodemographic, legal, and clinical admission data were analyzed. Participants with and without psychiatric diagnosis at admission were compared and independent factors associated with diagnosis at admission were identified through regression analyses. Results: Among 707 newly admitted male inmates, ~41% had a documented psychiatric diagnosis at prison entry, were younger, more frequently of foreign nationality, and more likely to report substance use. In multivariable analysis, substance-use profiles—particularly combined use of cannabis, cocaine, and psychostimulants (aOR = 11.55, p < 0.001)—and foreign nationality (aOR = 4.29, p < 0.001) were independently associated with documented psychiatric morbidity at prison admission. Awaiting final judicial disposition, age and first incarceration showed no significant association. Conclusions: A substantial proportion of individuals entering prison present with a psychiatric morbidity, with specific substance use profiles showing a strong independent association with outcome. These findings highlight the clinical complexity of individuals entering correctional settings and support systematic psychiatric assessment.