Abstract

Introduction: Dreaming allows for emotional processing. However, for those with psychiatric disorders, dream disturbances - namely nightmares- are prevalent. Nightmares disrupt this emotional processing, and their distress has demonstrated links to worsening clinical symptoms and increased suicide risk. Despite this, nightmares receive limited clinical attention in complex psychiatric populations. This is surprising when considering how these populations exhibit increased risk factors, such as trauma and distress, which may contribute to unique experiences of nightmares and increased association with externalising behaviours. Few studies focus on the link of nightmares to self-injurious behaviour (SIB). Systematic reviews on psychiatric populations have also failed to capture a broad understanding of nightmares in psychiatric inpatients alone. Forensic psychiatric sampling for nightmare research is particularly scarce, warranting investigation.

Materials and methods: A systematic review using Reflexive Thematic Analysis explored the nature, underlying mechanisms and correlating factors of nightmares in psychiatric inpatient populations. Titles were screened from eleven databases. Data extraction, quality assessment and inter-rater reliability were performed adhering to PRISMA guidelines. This systematic review identified variables for a review of collateral clinical information of detained forensic patients, utilising a structured clinical assessment tool, the Self-injurious behaviour Management and Behavioural Assessment (SIMBA). The SIMBA gathers clinical information based on staff reporting on mental illness, externalising behaviours and importantly, sleep challenges, including whether nightmares have presented. Mixed methods using Reflexive Thematic Analysis and regression explored what was reported about nightmares in these patients and associations with incidents of externalising behaviour.

Results: In relation to the systematic review, of the 9,534 titles screened, a total of 35 papers were included for review. Themes described the chronic and replicative nature of nightmares in psychiatric inpatients, including their violent, trauma-related and disturbing content. Underlying mechanisms of inpatient nightmares centred on trauma and emotional dysregulation, often with early onset. Inpatient nightmares demonstrated bidirectional links with exacerbating clinical symptoms, negative cognitions, distress and other sleep disturbances. The impact of nightmares on risk of suicidality was apparent. Patients in the case study papers were reported as keen to explore their nightmares, while other studies highlighted the unexplored therapeutic potential of nightmares. The methodologies and quality of the included papers varied. In the SIMBA study, nightmares were reported in 23% of the 78 patients reviewed. Themes highlighted how nightmares present as part of wider sleep disturbance, centre around trauma, and have multifaceted impacts. Patients appeared to discuss their sleep problems, yet limitations presented in staff reporting of nightmares. Nightmares qualitatively showed relationships with SIB but did not statistically predict externalising behaviours.

Conclusions: Both reviews overlapped in findings and provide initial understanding of the distressing nature of nightmares in complex psychiatric populations, their underlying mechanisms, interaction with psychiatric symptoms and limitations around assessment. Building on these results, a large study plans to explore nightmares from the perspective of male forensic inpatients and test the feasibility of a brief nightmare intervention. It is hoped that by addressing nightmares, sleep disturbances in high-risk populations can be addressed and patient wellbeing improved.