Solitary confinement is a widely implemented correctional practice, yet its psychological impact –particularly on individuals with pre-existing mental health conditions – has raised clinical, ethical, and legal concerns. This narrative review synthesizes findings from 35 peer-reviewed studies (2004-2024), identified through structured searches in PubMed, PsycINFO, and Scopus. The evidence demonstrates that solitary confinement may intensify psychiatric symptoms, contribute to the onset or worsening of psychosis, increase the risk of self-harm and suicide, and impair cognitive function. Neurobiological research further links isolation to adverse changes in stress response and brain function. Legally, its prolonged use for individuals with mental illness may contravene international human rights standards. The paper also examines potential alternatives and reforms, emphasizing the importance of evidence-based, mental health-informed correctional approaches. The review concludes that solitary confinement is disproportionately harmful for this vulnerable population and advocates for its severe restriction alongside the implementation of trauma-informed alternatives.
Tahan et al. (2025) studied this question.