2.1. Mental Health and the Criminal Justice System

In 2014 over 1.7 million people in the United Kingdom were in contact with the criminal justice system (Ministry of Justice., 2009). Many of these contacts will be limited and lead to no action on the part of criminal justice services. These people will experience the same range of mental health problems, (including learning disabilities, other neurodevelopmental disorders and dementia) as are found the general population in the United Kingdom, with a prevalence, across all disorders, of about 20%. However, for those who have more extensive contact with the criminal justice system the picture is different. For example, an estimated 39% of people detained in police custody have some form of mental health disorder. Over 25% of residents in approved premises have been found to have a psychiatric diagnosis (Ministry of Justice., 2015b). An estimated 29% of adults serving community sentences (there are currently around 120,000 people with community sentences (Ministry of Justice., 2013c)) have a mental health disorder. It has been estimated that over 90% of prisoners have at least one of the following psychiatric disorders; psychosis, anxiety, depression, personality disorder and alcohol or drug misuse. A study by Brooker et al (2011) reported that 27.2% of those managed by a country wide probation service in England had a mental disorder of which almost half had a personality disorder (47.4%). Some disorders such as personality disorders have a high prevalence in the prison population (approximately 85,000 (MoJ, 2016c)) approaching 60%, compared to 5% in the general population. The rate of psychotic disorders in those serving community sentences is 11% compared to 1% in the general population. There are other significant differences in the mental health problems between those in the general population and those in the criminal justice system. For example, 76% of female remand prisoners and 40% of male remand prisoners have a common mental health disorder (MoJ, 2015). In addition to considerable differences in formal psychiatric disorders, self-harm is very common among people in contact with the criminal justice system. Within a 12month period there were approximately 35,000 reported incidents of self-harm in prisons in England and Wales. This is a 27% increase from previous year (Ministry of Justice, 2016d). Of people detained in police custody, 16.2% reported current suicidal thoughts of whom 86.2% reported a history of self-harm or suicide attempts (Forrester et al, 2016).

An estimated 12% of people serving community sentences are at high risk of suicide (Cook & Borril, 2013). Among prisoners, 46% of men and 21% of women said they had attempted suicide at some point in their lives (Public Health England, 2016). According to the most recent review of health in the justice system there are, on average, 600 incidents of self-harm and 1 suicide every week within a prison in the UK (Public Health England, 2016). This is considerably higher than in the general UK population, with 6% of people saying they have previously attempted suicide. Among adults with mental health problems serving community sentences, an estimated 72% also screened positive for either an alcohol or drug problem. Drug and alcohol misuse is high, with an estimated 12% of adults serving community sentences having substantial or severe levels of drug misuse. Estimates of drug dependence within the prison population is 45% in comparison to 5.2% within the general population (Public Health England 2016). Of the people serving community sentences 52% are hazardous drinkers,

In addition to the common and severe mental illness, there are other characteristics of the population in contact with the criminal justice system than can present particular challenges. Within the prison population 7% have a learning disability (Prison Reform Trust 2012) compared to 2% of the general population. Up to 50% of the prison population suffer from some degree of traumatic brain injury compared to approximately 0.56% (Headway, 2015) of the general population.

People convicted of sexual offences accounted for 14% of the prison population and 7% of the probation population (including those on post release supervision and community orders). While the majority of people convicted for sexual offences are male, 2% are female (Ministry of Justice., 2013a).

Black, Asian and minority ethnic (BAME) groups are over-represented in the criminal justice system (MoJ, 2015c). It is estimated that BAME groups constitute 26% of the prison population compared with 9% of the overall population in England and Wales (Goodman & Ruggiero, 2008). For BAME groups, in particular young black men, contact with the criminal justice system may be an important route into mental health services, with BAME groups found to be 40% more likely than white British groups to access mental health services through a criminal justice system gateway. Other groups such as those older than 50 years and groups with comorbid disorders such as severe mental illness and drug or alcohol misuse, who are typically excluded from mainstream mental health services (Drake et al, 2000) are also a cause for concern (Drake & Mueser, 2000).

Contact with the criminal justice system can have considerable negative impact on family members, (SCCJR, 2015) and in particular on children (Murray and Farringdon, 2008) which may also raise significant safeguarding issues (HMG, 2015).

2.2. Current practice

The scope of this NICE guideline covers the mental health of adults in contact with the Criminal Justice System, apart from those whose sole contact is as witness or victim. It covers first contact with police service (whether or not an arrest is made) through the courts and prison system and on release from prison to continuing community support (including contact with probation services). This involves a number of complex and interweaving pathways beginning with the 1.7 million people who may have some form of contact with the criminal justice system to the unknown number of people with a mental health problem who appear before courts in the UK each year, the approximate 85,000 who are currently in prison and the approximate 250,000 who are in the care of probation or community rehabilitation companies (Ministry of Justice., 2016c). Of all criminal cases, 90% start and finish in the Magistrates Court^a. Given the complexity of the difficulties experienced by people with mental health problems in the criminal justice system, it is troubling to learn that services for them are not well developed. It is possible that many of these service users don’t reach the criteria of secondary care mental health services. Although a significant number of people coming into contact with criminal justice services may have a mental health problem and have had recent contact with services, a surprising number are currently not in contact with services. For example, in a recent evaluation of the Street Triage programme pilots, Reveruzzi et al (2016) reported that an average 60.6% of service users who came into contact with Street Triage were known to mental health services. However, the average number of service users currently engaged with services was relatively low at 19.2% (Reveruzzi et al., 2016). In addition, recognition of mental health problems in prison settings is poor, with many common mental health disorders going unrecognised. Where problems are recognised treatment is difficult to access or unavailable. There is evidence that these problems accessing treatment are, in part, due a reluctance on the part of some health care professionals to offer services to people involved in the criminal justice system (Thornicroft et al., 2007) and to limitations of effective assessment and monitoring at the beginning of a prison sentence (Slade et al, 2016).

For most people in contact with the criminal justice system health care comes from community primary and secondary care health services. In the prison system the situation is different. Across the whole prison estate there is access to a primary healthcare service akin to that of general practice in the community. These services are supported, to a greater or lesser extent, by mental health services. The dominant model has been the mental health inreach team (Steele et al, 2007). This is moving to a hybrid model of primary care and in-reach based services. Another important difference between prison and non-prison based services is the role played by prison staff. In addition to maintaining safety and good order in the prison, they are involved in providing an important role in the recognition and management of mental health problems. Other prison service staff, offender management staff, substance misuse teams, staff from third sector organisations, educationalists and forensic psychologists also have a significant role in supporting people with a mental health problem. Of these staff groups, only those working in primary care and specialist mental health teams are employed by the NHS. This, along with the complex nature of the mental health and physical health problems experienced by prisoners, leads to a complex relationship between the prisoner and the National Health Service. This can lead to significant problems with the delivery and coordination of care, particularly when a person leaves prison. A particular problem which arises is in arranging in-patient care for someone in an acute psychotic episode. Problems accessing hospital beds lead to long delays and tensions between those whose main concern is reduction of offending behaviour and the maintenance of safety and security and those whose main concern is the provision of healthcare.

Unfortunately, despite people in contact with the criminal justice system having the same rights of access to health care as the general population, the reality is there are difficulties in doing so (Bradley, 2009). There are court disposals which are intended to ensure people get access to treatment which is contained in a Community Order. Community orders were introduced as a sentencing option the Criminal Justice Act 2003. As a high level community order, which can be an alternative to a custodial sentence, the Courts may impose mental health treatment requirement orders (MHTR) or drug rehabilitation orders (DRO). Supervision of the delivery of these orders rests with probation service staff. Should an individual subject to community order, or post-release supervision, breach the requirements of the order, they can be returned to court or to prison. The Legal Aid, Sentencing and Punishment of Offenders (LASPO) Act 2012 brought in changes relating to the Mental Health Treatment Requirement. Now any medical practitioner can hold the order, whereas previously the order had to be held by a Section 12 approved doctor. This means the order can be provided by both primary and secondary care practitioners. Despite the potential benefits of a MHTR supporting someone with mental health problems, they are not commonly used. They comprise of less than 1% of all requirements of orders (NOMS 2016). The Five Year Forward Plan for Mental Health has recommended ‘increased uptake of Mental Health Treatment Requirements (diversion through court order to access community based treatment) as part of community sentences for everyone who can benefit from them.’ (NHS England, 2016)

Some people on probation or post-release licence may be subject to multi-agency risk assessment conference (MARAC) or multi-agency public protection arrangements (MAPPA) processes. These processes are aimed at promoting effective inter-agency working. Decisions about who is subject to MAPPA or MARAC is based on offence type and risk level determined by probation service providers.

The emphasis so far has been on problems of access to mental health services by people in contact the criminal justice system. However, loss of contact with mental health services, particularly for the more severely ill, can lead to criminal justice services having a role in crisis response services. An example of this is the development of Street Triage services which aim to identify people with mental health problems and arrange, or signpost to, appropriate care as soon as possible after contact with the criminal justice system. A related function is that of liaison and diversion teams based in police custody suites and courts. They provide advice to the criminal justice system about care, management and processing of people in contact with it. They facilitate access into mental health and addiction services. There are various models for street triage and liaison and diversion services which will be responsive to local needs and resources. Not all police services and courts have access to liaison and diversion services.

Outside of the prison system, where there are established screening tools, case recognition and identification systems are limited. Not all people who may benefit from an assessment by a forensic medical examiner or a liaison and diversion practitioner in police custody, or a specialist team in a court diversion scheme, will be identified and offered a further assessment. In police custody people may be intoxicated and a lack of specialist police training may further hinder effective recognition of mental health problems. In prison settings a lack of similar training for prison officers can be an impediment to improved recognition. The consequences of this may be untreated disorders and inappropriate referrals and use of criminal justice and health care services. Of particular concern are those people with neurodevelopmental disorders, learning disabilities and acquired cognitive impairment which will often go undetected. This can have significant consequences for the person who may be denied effective treatment (for example, methylphenidate for ADHD) and support which can have negative consequences which prompt recognition and effective assessment and treatment could have avoided.

2.3. The Relationship between Offending and Mental Health Problems

The issue if the causal relationship between offending behaviour and mental illness has been the focus on much discussion. There is some evidence which suggest that certain disorders, particularly those managed in forensic settings are associated with different and higher rates of offending. For example, Coid et al (2015), in a review of patients discharged from medium secure units, showed risks of all types of offending were increased for personality disorder, violence and acquisitive offences for delusional disorder and organic brain syndrome and sexual offending for mania and hypomania (Coid et al., 2015). However, in a study including non-forensic populations, Fazel and Yu (2011) identified an increased risk of re-offending with psychotic disorders when compared to the general population but not when compared to other psychiatric disorders (Fazel & Yu, 2011). Yet other studies such as that by Stevens et al (2012) have suggested that offending behaviour may pre-date presentation to mental health services. Factors other than a mental disorder may be important in determining offending behaviour (Stevens et al., 2012). One study indicated that homelessness may be associated with increased offending (Roy et al., 2014). The same study reported that homeless severely mentally ill people were more likely to be victims of crime, a finding supported by a study by Teplin et al (2005). Finally, it should be remembered that the data indicates that although some disorders may contribute an increased likelihood of offending, effective treatment can reduce the likelihood of further offending (Pickard & Fazel, 2013).

The precise mechanisms which underpin the relationship between crime and mental illness are complex and varied and in many cases not well understood. It appears that pre-existing social factors, for example homelessness, may be important. Other areas such as substance misuse and acquisitive crime may be driven by the need to buy illicit drugs. Some illnesses, such as delusional disorder, may cause a direct link to the offence. For other disorders, the link may be less explicit, for example in neurodevelopmental disorders such as ADHD. This may result in impulsive and recklessly behaviour without consideration of consequences. There are several different relationships between mental health problems and offending behaviour. Offending behaviour can be the result of mental health problems on behaviour, for example disinhibition related to frontal lobe damage. The relationship may be the presence of underpinning social antecedents that predict mental health problems and are associated with an increased risk of offending, for example experiencing adverse life experience. Additionally, the consequence of offending and contact with the criminal justice system may result in mental health problems, for example job loss, relationship failure and social stigmatisation. This last relationship is least well studied and is focused on the social consequences of conviction rather than the traumatising nature of contact with the Criminal Justice which may occur. Although arrest, especially wrongful arrest and imprisonment have been cited as traumatising experiences (Scott, 2010). There are many ethical and philosophical considerations that can be made about the relationship between offending and mental health problems.

Understanding the relationship between mental health problems and the criminal justice system has important consequences. It informs treatment and management of people with mental health problems in the criminal justice system and the relationship between mental health services and the criminal justice system.

One issue which warrants attention is that of mental capacity. For adults there is a presumption of capacity unless demonstrated otherwise. From the perspective of healthcare an adult with capacity is one who can make decisions about their care and treatment. To make a decision someone needs to be able to understand what course of action is being proposed, the consequences of their decision, weigh up different views in order to make a decision and communicate their decision. This principle is enshrined in clinical practice and is underpinned, reinforced and standardised by the Mental Capacity Act.

In the criminal justice system, issues around capacity are relevant. The time when this is given rigorous consideration is fitness to plead. Issues around fitness to plead are raised in a minority of criminal court appearances. Fitness to plead is determined by a medical assessment of someone’s ability to instruct council, understand the nature of the charges levelled against them, follow evidence, challenge jurors who they believe may be biased against them and understand the difference between a plea of guilty and not guilty. There is an interesting difference here between the approach to assessing fitness to plea which relies on external evidence and assessing capacity which should be performed by all health professionals which may cause concern. It is arguable that this is appropriate given the potential consequences if someone lacks capacity during their court appearance. Although a counter argument may be that the court is most expert in explaining the processes of the court and checking understanding, as opposed to this being done by external medical experts.

Elsewhere in the criminal justice system, individual workers are alert to potential problems around capacity and how it can effect engagement but processes are not as well defined or described. When taken into custody, the custody sergeant will consider whether someone is fit for detention and fit for interview. How this decision is reached is variable and may rely on the decision of a single healthcare practitioner. Whilst the Police and Criminal Evidence Act requires the use of an Appropriate Adult, there is less routine consideration of whether someone has sufficient capacity to engage effectively with the criminal justice system. Addressing these issues is very much dependent on individual practitioners. There are instances, in clinical practice, of individuals with learning disability, or other severe neurodevelopmental disorders, who have been through the court system and imprisoned without any explicit consideration of their capacity to participate in court proceedings, plead or engage with the criminal justice process.

The next issue concerns the detention of people with severe mental illness in prison. Can prison ever be a proper place to manage a person who continues to be significantly disabled by a severe mental illness, particularly if their symptoms and poorly controlled. If someone requires intensive care which is not available in a prison setting. Similar arguments can be made about dementia, which is increasing as the prison population ages and presents novel management issues in the prison estate (Moll, 2013). The final issue is whether sexual offences against children are seen as a paraphilia, which is a mental disorder. Currently the approach is to see the problem as a criminal offence but to offer treatment after conviction.

2.4. The Relationship between the Criminal Justice System and Mental Health Services

The interplay between two large publically funded systems, both operating in a highly regulated and risk adverse environment, is inevitably complex. There is enormous local variation (for example, Kosky and Hoyle, 2013) and for which only an overview can be provided here. People in contact with the criminal justice system who have, or are suspected to have, a mental health problem have access to the whole range of normal healthcare services unless they are held in prison. However, there is wide variation in the availability of specialist services, particularly those providing psychological treatments. Nevertheless, the basic building blocks of good mental health care (GP led services, community mental health teams, substance misuse services) are routinely available. There are cultural and particular reasons why individuals may not engage with this offer, but the services themselves do exist. It is worth noting that for those with multiple needs, there can be difficulties accessing services due to dual diagnosis of substance misuse and mental health problems. This is emphasised where there is a lack of clarity over responsibility for care in conjunction with offender management. For those who are detained in prison, whether on remand or serving a sentence, it is a different story, one characterised by delay and under-resourcing (Forrester et al, 2013). Since 2003, the National Health Service has been responsible for the provision of care in prisons. Prior to this, responsibility lay with healthcare professionals directly employed by the Ministry of Justice. Reasons for transferring to care provided by the health service included a desire to establish equity of service provision, improved quality of care and to improve liaison and coordination with local mental health. But it is not clear whether these benefits have actually been realised (Forrester et al, 2013).

2.5. Transitions between the Criminal Justice System and Mental Health Services

A central concern of those receiving and providing mental health care in the Criminal Justice System is the need to be able to successfully navigate the large number of transitions that can take place.

These transitions fall into several categories. Grouping them loosely together they are:

1. Transitions in geographical location. This particularly applies to people who are imprisoned, often at some distance from their normal place of residence. They may be subject to several moves during their period of detention before being moved to a prison for resettlement, ideally near the place where they will be living. There then follows a further shift of location from prison to the community, perhaps after a period of some weeks, months or years, with a potential absence of established or healthy social networks to return to.
2. Transitions in healthcare provider. In an ideal situation there would be seamless transfer from the care of the General Practitioner, perhaps with the support of a community mental health team, to a custody liaison and diversion team. Should the person be imprisoned, a seamless transfer to the prison mental health in-reach team and prison primary care services. This should include appropriate onward referral to services of other prisons should there be a move of prison and then release into the community with a coordinated handover of care to community services. Sadly, this is rarely the case. Although some transition points are managed better than others.
3. Transitions in status. These are the subtlest and often the hardest to quantify, but can have a profound effect on a person’s opportunity to develop agency and demonstrate control of their life. The criminal justice system becomes involved when, essentially, the person’s willingness or ability or decision to manage their life in a pro-social way fall short of societal norms. However and perhaps for understandable reasons, contact with the criminal justice system as an offender is stigmatising and can lead to difficulty in navigating life’s hurdles even after the “debt to society” has been repaid.

Problems of transition in these areas can occur for many reasons. People in contact with the criminal justice system are often suspicious of those they perceive to be authority figures, have difficulty establishing meaningful relationships with care providers, may have communication difficulties and may have profoundly complicated personal and medical histories. All of these factors conspire to make giving a reliable and complete history to medical professionals, especially upon a repeated basis, very difficult. In addition, there is often ignorance about the complexity of the criminal justice system and how to relate to it on the part of health professionals. There can be an insufficiently considered approach to the management of confidentiality and the need to convey information to other agencies. Additionally, there can be a reluctance, especially for those health professionals in the community for whom contact with the criminal justice system is not a frequent occurrence, to deal with people with a history of offending. There may be a lack of appreciation of the complexity and multiple medical and social morbidities that people in contact with the criminal justice system demonstrate. This last factor is particularly so for disorders that an individual does not necessarily complain about directly, particularly neurodevelopmental disorders, cognitive impairment from a variety of causes and continuing substance misuse. The most profound reasons for failure to manage transitions successfully, however, is problems with information flow. There can be a lack of information sharing between agencies working across the criminal justice system. This lack of information sharing can mean that the courts do not have access to information they need in order to ensure fair and efficient court processes, including appropriate sentencing options. In part this is due to the aforementioned human factors but primarily because of the lack of a coherent information system among healthcare providers which is often compounded by partial, or no, access to the information held on criminal justice system databases. There are legal, ethical and practical problems of getting those two systems and the people who operate them to communicate effectively with one another. There are particular problems around medicines reconciliation at all points in a person’s journey through the criminal justice system. Given the high level of psychoactive substances prescribed or used in this population, this is an area of particular concern.

Delivering effective treatment options in prison may also be limited by the restrictive nature of the prison environment. Additionally, the Mental Health Act does not apply within prison healthcare settings (with the exception of sections 47 and 48 for the transfer of prisoners to and from hospital). People who are sectioned while in the community are transferred to NHS inpatient facilities. However, there are often long delays in transfers going ahead.

Rehabilitation and resettlement into the community is also complicated by the lifetime of social exclusion experienced by many prisoners. For example, many sentenced prisoners are not registered with a GP before entering prison and people may face difficulties in finding a GP willing to accept them as a patient after release.

2.6. Economic Costs

Current healthcare provision, including mental healthcare, for people in contact with the criminal justice system is the responsibility of the NHS, with the exception of people under police custody and court custody. The care of people with mental health problems in contact with the criminal justice system impose a substantial burden on the NHS, criminal justice sector and the wider public sector.

In England and Wales, the prison population was approximately 85,000 during the last months of 2015 (Ministry of Justice. & HM Prison Service., 2016) and there were 118,100 community orders given out in the 12 months ending June 2015 (Ministry of Justice., 2015a). All of the people in these groups have a very high risk of mental ill health. For example, 10% of men and 30% of women have had a previous psychiatric admission before they entered prison; 18% of prisoners were assessed as suffering from anxiety and depression (Ministry of Justice., 2015b) (MoJ, 2012); and 62% of male and 57% of female sentenced prisoners have a personality disorder (Prison Reform Trust., 2013).

It is estimated that £1.6 billion is spent annually on arresting, convicting, imprisoning and supervising people with identified mental health problems, rather than treating or supporting them (Revolving Doors Agency., 2007). In general, people with mental illness have a higher probability of having contact with the criminal justice system. In the US, Ascher-Svanum and colleagues (2010), assessed the prevalence of contacts with the criminal justice system and the estimated cost attributable in the one-year treatment of persons with schizophrenia (Ascher-Svanum et al., 2010). Criminal justice system involvement was assessed using the service user survey. It was estimated that 278 (46%) of 609 participants reported having contact with the criminal justice system at least once. The mean annual per-service user cost of involvement was $1,429 per person, translating to 6% of total annual direct healthcare costs for those with involvement (11% when excluding crime victims) (in likely 2009 US dollars).

In another US study, Petrila and colleagues (2010) examined the expenditures related to the criminal justice, health, mental health and social welfare services over a 4-year period for arrestees with severe mental illness (schizophrenia, schizoaffective disorder, delusional disorders and other psychotic disorders and also bipolar I disorder and major depressive or other bipolar and mood disorders) in a Florida county (Petrila et al., 2010). According to the analysis, the aggregate expenditures for the cohort were $95 million over the 4-year period, with a median per person expenditure of $15,134 (in likely 2009 US dollars). Overall, as much as 39% of expenditures were associated with mental health services. Besides, individuals with mental illness remain incarcerated longer than inmates without mental illness charged with the same offences (McPherson, 2008) and after release, re-arrest is common (Cox et al., 2001; Hartwell, 2003; Lamb et al., 2004). Robertson and colleagues (2015) examined the costs in people with mental health problems who have criminal justice involvement and those that do not (Robertson et al., 2015). The authors reviewed administrative records from public behavioural health and criminal justice agencies of 25,133 adults with schizophrenia or bipolar disorder. It was found that costs were nearly 27% higher for those with justice involvement compared with those who had no justice involvement ($31,166 versus $24,602) (in likely 2014 US dollars). Thus, people with severe mental illness who are in contact with the criminal justice sector cause considerable financial burden on public sector services.

Where mental illness is not recognised and is not treated properly there is a potential for repeat transitions between hospital admission, discharge and readmission. People with mental illness in prison are frequently caught in a downward spiral of non-recovery. The costs of this are substantial and include transporting and reprocessing individuals who require varying levels of mental health treatment, personal costs to individuals and their families, added staff workload and stressed and frustrated prison staff.

There seems to be a strong case for diverting offenders away from sentences in prison towards effective treatment in the community. There is an increased risk that vulnerable people’s conditions are not being identified or treated, exacerbating mental health problems and frequently leading many to reoffend, self-harm or commit suicide (Bradley., 2009). Effective diversion requires some up-front investment in dedicated liaison and diversion teams working in police stations and courts. In the UK, a financial report commissioned for the Bradley review (2009) estimated that to implement an effective triage and assessment service, would cost between £3m and £9m nationally across all police forces. But there will be wider implications on the potential impact on reducing reoffending. There is increasing evidence that well-designed interventions can reduce reoffending by 30% or more. The economic and social cost of crime committed by recently released prisoners serving short sentences amounts to £7-10 billion a year. Much of this cost falls directly on the victims of crime, but 20-30% is borne by the public sector, mainly the criminal justice system and the NHS. And the total lifetime cost of crime committed by an average offender following release from prison is of the order of £250,000 (Centre for Mental Health. et al., 2010). In another exploratory analysis conducted by the Centre for the Mental Health (2009) it was estimated that the combined costs of diversion and liaison schemes in the UK is around £10 million a year (Centre for Mental Health., 2009). The authors argued that there is good evidence that offenders with mental health problems are more likely to be held on remand than other offenders and each additional case held on remand imposes, on average, additional costs of £3,000 on the criminal justice system.

Another issue is the need for services to support community resettlement following incarceration and continuity of care initiated in prisons. Most of the evidence in this area is from the US and Australia. In the US Lin and colleagues (2015) developed an economic model to estimate the cost burden of psychiatric relapse and reoffending among service users with schizophrenia recently released from prison from a US state government perspective (Lin et al., 2015). Among 34,500 persons released from prison in the state of Florida annually, 5,307 were estimated to have schizophrenia. The cumulative 3-year costs to the state government were $21,146,000 and $25,616,000 for criminal justice and psychiatric hospitalisation costs, respectively ($3,984 per service user criminal justice costs; $4,827 per service user hospitalisation costs) (in likely 2014 US dollars).

In another study, Alan and colleagues (2011) examined the resource use in ex-prisoners within the first 12 months of release from prison in Western Australia (Alan et al., 2011). It was found that one in five adults released from prisons between 2000 and 2002 were hospitalised in the 12 months that followed, which translated into 12,074 inpatient bed days and associated costs of $10.4 million. Mental health problems such as schizophrenia and depression and head or facial injuries or fractures accounted for as much as 58.9% of all bed days. Ostermann and colleagues (2013) estimated the costs of crimes committed by reintegrated former prisoners with mental illness and compared these costs to those without mental illness (Ostermann & Matejkowski, 2013). It was found that that the recidivism costs of those with mental illness over the course of 3 years of follow-up are nearly 3 times as large as for former prisoners without mental illness. This indicates the importance of treatment during someone’s prison stay and the need for services to support community resettlement in reduction of health service costs.

Similarly, substance abuse is associated with great economic costs in this population. McKenzie and colleagues (2005) reported costs associated with opiate replacement therapy at time of release from prison in the US. The authors reported the annual cost of methadone replacement therapy to be approximately $4,420 per person. In another, study Werb and colleagues (2007) reported costs associated with drug treatment courts in Canada (Werb et al., 2007). The authors reported the cost per person to be $21,265 for Vancouver drug court programme participants and $13,117 for matched controls. They further went on to report the total costs of the Vancouver drug court programme during the period of 2001 and 2005 to be £4.1 million. With 42 participants who either graduated or completed the programme, the cost per graduates or completer was as high as $96,639. Bechelli and colleagues (2014) reported that in Washington State the average per client cost of substance abuse treatment for the period 1998–2007 was $6,504 (Bechelli et al., 2014).

All of the above indicates that the management of people with mental health problems who are in contact with the criminal justice system cause a substantial financial burden on the NHS, criminal justice sector and the wider public sector. Individuals with mental health problems who are in prisons are less likely to adjust to the prison life; they are vulnerable to repeat hospitalisations; and have a higher risk of future crime associated with the untreated mental illness. There is a need for UK-based evidence to better understand the interface between the mental health services and the criminal justice systems and the related economic costs and economic evaluations to identify cost-effective treatment strategies and service configurations for this population.