Objective: To compare two levels of stress (solitary confinement (SC) and non-SC) among remand prisoners as to incidence of psychiatric disorders in relation to prevalent disorders.
Method: Longitudinal repeated assessments were carried out from the start and during the remand phase of imprisonment. Both interview-based and self-reported measures were applied to 133 remand prisoners in SC and 95 remand prisoners in non-SC randomly selected in a parallel study design.
Results: Incidence of psychiatric disorders developed in the prison was significantly higher in SC prisoners (28%) than in non-SC prisoners (15%). Most disorders were adjustment disorders, with depressive disorders coming next. Incident psychotic disorders were rare. The difference regarding incidence was primarily explained by level of stress (i.e. prison form) rather than confounding factors. Quantitative measures of psychopathology (Hamilton Scales and General Health Questionnaire) were significantly higher in subjects with prevalent and incident disorders compared to non-disordered subjects.
Conclusion: Different levels of stress give rise to different incidence of psychiatric morbidity among remand prisoners. The surplus of incident disorders among SC prisoners is related to SC, which may act as a mental health hazard.