Loading the library…
confinement & mental health
The operative claimSolitary confinement is associated with substantial adverse psychological effects — distress, self-harm, and elevated suicide/mortality risk — with harms that appear to exceed those of general incarceration and that fall most heavily on those with mental illness and on adolescents; the evidence is consistent across two centuries though complicated by selection and measurement, and professional bodies oppose its use for juveniles.
Established that solitary confinement is associated with substantial psychological harm, acute for adolescents and the mentally ill, though selection complicates causal magnitude.
A meta-analysis (382,440 inmates) links solitary to adverse psychological effects (SMD ~0.45), self-harm, and mortality beyond general incarceration (Luigi et al., 2020), and a systematic critique documents strikingly consistent harm findings since the 19th century (Haney, 2018). For adolescents, reviews report developmental and suicide-risk concerns and broad professional opposition (Lindahl et al., 2021), and isolation predicts more mental-illness diagnoses among waived juveniles (Valentine et al., 2019). A within-person study reports counterintuitive improvement confounded by increased treatment (Siennick et al., 2022).
Luigi, M., Dellazizzo, L., Dumais, A., et al (2020). Shedding Light on "the Hole": A Systematic Review and Meta-Analysis on Adverse Psychological Effects and Mortality Following Solitary Confinement in Correctional Settings. Frontiers in Psychiatry.
Meta-analysis
Solitary confinement was associated with increased adverse psychological effects (SMD 0.45 for general symptomatology), self-harm, and mortality (especially suicide), with the effect appearing beyond that of general incarceration or prior mental illness.
Bearing on this claim: Meta (382k): adverse psychological effects (SMD 0.45), self-harm, mortality beyond general incarceration.
doi.org/10.3389/fpsyt.2020.00840Haney, C (2018). The Psychological Effects of Solitary Confinement: A Systematic Critique. Crime and Justice.
Review
Findings on solitary confinement's adverse psychological effects have been strikingly consistent since the 19th century; the prevalence of psychological distress is extremely high, and the recent studies claiming "no effect" are methodologically flawed.
Bearing on this claim: Critique: harm findings strikingly consistent since 19th century; "no-effect" studies flawed.
doi.org/10.1086/696041Lindahl, J., Hirsch, S., et al (2021). Adverse Psychiatric and Health Impacts of Restrictive Housing for Adolescents in Juvenile Correctional Settings. Journal of the American Academy of Child and Adolescent Psychiatry.
Review
Solitary confinement / restrictive housing for incarcerated adolescents is widely opposed by professional bodies (AAP, AACAP) given mental-health and suicide-risk concerns at a developmentally vulnerable stage; many states restrict or limit it.
Bearing on this claim: Adolescent review: developmental/suicide-risk concerns; broad professional opposition (AAP/AACAP).
doi.org/10.1089/jchc.2021.29006.ncchcValentine, C. L., Mears, D. P., & Bales, W. D (2019). Prolonged isolation as a predictor of mental health for waived juveniles. Journal of Offender Rehabilitation.
Observational
Among juveniles waived to adult corrections, more time spent in segregation was significantly associated with a greater number of mental-illness diagnoses — isolation's harms may be amplified for younger offenders in adult facilities.
Bearing on this claim: Waived juveniles: more segregation time -> more mental-illness diagnoses.
doi.org/10.1080/10509674.2019.1596188Counter-authority (1). Studies an adversary may cite — surfaced deliberately so the grade is honest about its limits.
Siennick, S. E., Picon, M., Brown, J. M., & Mears, D. P (2022). A Within-Person Test of the Impact of Extended Solitary Confinement on Mental Health Functioning and Service Use. Criminal Justice and Behavior.
Observational
Using within-person analysis, during extended solitary stays service use increased while psychological functioning improved and mental-health crises declined — a counterintuitive result (confounded by increased treatment) that complicates simple causal claims.
Bearing on this claim: Within-person: functioning improved during solitary — confounded by increased treatment.
doi.org/10.1177/009385482211319534 supporting · 1 counter verified sources
Causal inference is complicated by selection into solitary and by concurrent treatment; measurement of psychological harm varies; and effects differ across populations and confinement regimes.
Last reviewed June 28, 2026