This study provides an updated picture of the mental health needs of both male and female prisoners in the UK. A cross-section of male and female prisoners from 13 prisons in one region of the UK were assessed for a range of mental health issues using a battery of validated screening measures. The current study represents one of the largest studies of the mental health needs of prisoners in the UK, in terms of sample size and number of establishments included, since the ONS Survey in 1997 [4]. Over half of participants reported having had previous contact with mental health services either in prison or in the community, rates much higher than those reported in the general population [21]. Further a high number of participants reported having previously being diagnosed with a mental disorder; however, only around half of these also reported current contact with prison mental health services. In terms of current mental health need, prevalence rates for current mental disorder were high, with particularly high levels noted for personality disorder, anxiety, mood disorders and risk of suicidal behaviours. Levels of comorbidity were high, with over half of all participants screening positive for two or more types of mental disorder on the screening measures. Of those participants who screened positive for a current mental health issue, a large proportion reported having no current contact with mental health services. Females reported significantly higher levels of mental health need compared to males (both current and pre-existing): particularly in relation to personality disorders, mood disorders, PTSD, eating disorders, psychotic disorders, and risk of suicidal behaviours. Females’ mental health needs appeared to be better met than that of males.

Comparisons with the literature

Rates of previous contact with mental health services and having a lifetime diagnosis of a mental disorder are similar to those reported in previous research with UK prison samples [5, 7], indicating that a significant proportion of prisoners continue to arrive in prison with pre-existing mental health issues. Despite this, less than half of participants with a pre-existing diagnosis reported current contact with Mental Health Inreach. This finding is consistent with previous research [22], suggesting that only a relatively low proportion of individuals who arrive in prison with pre-existing mental health issues are both identified and provided with treatment.

Rates of mental disorder in the current study were well above those of the general population reported in meta-analyses and large population studies, consistent with previous research in the area [4,5,6], suggesting that mental disorder continues to be highly prevalent amongst individuals in prisons. In particular, prevalence rates were 4.5–5 times higher than that found in the general population for personality disorder (54.8% vs. 12.2% [23]), anxiety (36.2% vs. 6.7% [24]), mood disorders (24.5% vs. 5.4% [24]), and PTSD (16.4% vs. 2%; [25]). Prevalence rates were also above that of the general population for both psychotic disorders (18.1% vs. 0.03% [26]), and eating disorders (19.6% vs. 10.1% [27]). The elevated rates of unmet need detected in the current study are consistent with those found in previous research [6], suggesting that many individuals in prison experiencing current mental health issues either go unidentified or are unable to access treatment.

Prevalence rates for both pre-existing and current mental health needs were generally higher among women compared to men, consistent with previous research [4,5,6,7, 28, 29]. Prevalence rates across the range of mental disorders screened for varied slightly to other previous UK-based research in the area [5, 6]. For example, rates for drug and alcohol dependence were much lower and rates of anxiety were slightly higher. These differences may reflect changes in the prison population (e.g., overall increase) or variations in the types of prisoners sampled (e.g., different proportions of remand and sentenced prisoners). Alternatively, this may reflect differences in the measures used to assess mental disorder across studies. For example, the current study utilised self-report screening measures, as opposed to diagnostic measures or structured clinical interviews. Some researchers have argued that screening measures can sometimes overestimate the prevalence of disorders in prison samples due to the inclusion of non-specific items and lack of validation in this population [1]. However, the measures used in the current study are frequently used for screening in forensic settings as well as in prison research. Further, given the current study used a cross-sectional design it is also possible that some individuals with mental health issues were either not captured or declined to take part in the study.

One notable point is that this study is one of the first to examine the prevalence of eating disorders in both male and female UK prisoners using a standardised screening measure. Previous research in this area has either collected self-report data on previous diagnosis of an eating disorder [5] or has conducted screenings with just a small sample of women in a single establishment [20]. The prevalence rates of risk of eating disorders among women in the current sample were 2.5 times higher than the rate detected in the general population using the same measure [13], with the reported rate amongst men being just above that of the general population. This suggests that women in prison may be at a higher risk of eating issues compared to the general population.

Generalisability

Whilst this study represents one of the largest epidemiological studies of mental disorder in prisoners undertaken in the UK since the ONS 1997 survey, the sample size is still relatively small when compared to the total UK prison population (3.4% female population, 0.4% male population). However, the prisons that the study sample was drawn from represent a third of all female establishments and approximately 10% of all adult male establishments in the UK. Further, the findings of the current research represent individuals from across a range of prison settings (high security, closed conditions, open conditions, local remand), sentence lengths (short and long term), and offence types. Although the current study draws upon a wide and diverse sample of participants across a range of settings, some groups were under-represented in the sample. For example, older adults (i.e., those over 55 years old) represented only a small proportion of the overall sample (7.9%) as did those on remand (9.8%). The under-representation of these groups can be partly attributed to the establishments in the region from where participants were recruited from (i.e., the majority holding sentenced prisoners). However, given that previous research has shown that remand prisoners have slightly differing mental health needs to sentenced prisoners and that the number of older adults detained in prisons has rapidly increased in recent years, further work is needed to understand the specific mental health, social care and treatment needs of these populations to inform policy and provision for these groups [1].

It is important to consider, when interpreting the results of this study, that the findings represent a point-in-time snapshot; thus, it provides an updated picture of the mental health needs of men and women detained in UK prisons sampled at the time of the research. However, any conclusions regarding causality of mental ill-health are not able to be drawn from the findings. Previous research shows that compared to the general population, people in prison are significantly more likely to have experienced adverse events prior to incarceration which have been linked to the development of mental health issues. Thus, many people in prison experience mental health issues prior to their arrival in custody [30]. For example, “imported factors” such as pre-prison dispositions, childhood sexual abuse, and learning difficulties have been found to be significant predictors of within-prison mental health status [31]. However, the psychosocial experience of imprisonment has also been found to act as an additional stressor upon individuals’ mental wellbeing [32]. Subsequently, there is a wider need for high-quality longitudinal research to examine the impact of the current prison environment on mental health, risk factors for the development of mental health issues in prison, and the effectiveness of interventions for assisting individuals in prison to recover/manage their mental health needs. Such research should also focus on current use of substances, including psychoactive substances, within the prison environment and self-injurious behaviours, which were not examined as part of the current study.

Clinical implications and future directions

Identification of both pre-existing and current mental health issues amongst those detained in prisons is critical for the planning and development of assessment and treatment services in these settings, as well as being vital for helping those who need it to access appropriate support both within the prison environment, with legal proceedings, and for successful rehabilitation and community reintegration [33]. However, both the current study and previous research in the field suggest that only a small proportion of individuals who either report a previous diagnosis or screen positive for a current mental health need currently receive treatment within prison [6, 22]; potentially indicating high levels of unmet need. Previous research suggests that as many as 46–64% of prisoners’ mental health needs remain unmet [6, 22], with the current study highlighting significant differences in the levels of unmet need between men and women across several mental disorders. Thus, accurate and timely identification of treatment needs is critical to improving this rate. To aid this task, it is essential that community mental health services, general practitioners, and prison Mental Health Inreach teams work together to ensure continuity of care during the transition process between community and custody and vice versa. Joint working and the sharing of information between services will not only enable more effective identification of individuals with known mental health issues but will also enable effective and efficient continuity of treatment.

In terms of identifying mental health needs upon individuals’ arrival in prison, many factors may impact upon the initial screening process, whether someone is accepted for treatment, and how long the wait for this is. However, our findings reinforce previous research, suggesting that current screening tools potentially lack sensitivity and specificity [22] and that a more comprehensive, in-depth, and gender-focused primary mental health screen upon initial reception to prison could help to identify those who warrant further assessment and/or treatment for mental health issues; for example, incorporating standardised screening for eating disorders, suicidal risk and PTSD for female prisoners. Further, initial reception screening alone may not be sufficient to identify all of those who have or may develop mental health issues as a result of incarceration. The current study sampled prisoners at various stages in their sentence pathway and the high levels of prevalence detected suggests that additional screening points during incarceration may be beneficial to ensure adequate support is provided as and when needed. Research examining the effectiveness of current screening and care models in identifying and meeting the mental health needs of those in prison would be highly beneficial to healthcare providers, commissioners, and policy makers.