Borderline Personality Disorder (BPD) is characterized by significant impulsivity and pervasive instability in affect, self-image, and interpersonal relationships, often leading to high rates of substance abuse, antisocial behavior, and self-harm or harmful behaviors toward others. This emotional instability increases the risk of involvement in the criminal justice system. Understanding BPD is crucial for providers working in correctional facilities, as it can inform the development of targeted treatment programs to aid inmates’ successful reintegration into society. Major Depressive Disorder (MDD) is notably more prevalent in the prison population than in the general public. The stressful nature of imprisonment and the lack of adequate coping mechanisms significantly contribute to the onset of MDD among inmates. Despite the high prevalence, only 33.8% of inmates with mental illnesses receive treatment, and only 26.8% adhere to their medication regimen. Risk factors include affective isolation, constant surveillance, lack of intimacy, frustration, restricted movement, identity loss, stigma, and social discrimination. Several screening tools exist for detecting depression in inmates, with the BJMHS, CMHS-M, CMHS-W, EMHS, and JSAT being the most promising. In this chapter, we look at common factors that these psychiatric disorders exhibit in the prison population, as well as the reintegration process for these individuals when they are released.