Introduction

The increase in the use of imprisonment is referred to by penal scholars by a variety of terms, such as ‘mass incarceration’ or ‘the penal state’. These terms capture the shift that has occurred since the early 1980s whereby rates of imprisonment have almost doubled in some countries. The US led the way in the expansion of the use of imprisonment. There are now more than 2 million Americans in custody. The overwhelming majority of prisoners – as in all countries – come from poor, urban communities. Racial minorities are overrepresented (Simon, 2007; Clear, 2009; Alexander, 2012). These developments in the penal system have taken place during a period when mental health institutions have closed. This chapter will explore the relationship between deinstitutionalisation and the increase in the use of imprisonment. The chapter begins with a consideration of the problem of how we define ‘mentally disordered offenders’. There is then a brief outline of the Penrose Hypothesis (Penrose, 1939; 1943), which sought to explain the links between the use of imprisonment and institutionalised psychiatric care. This approach will be used as a critical lens through which to examine policy developments in this area. Broader issues regarding the treatment of mentally disordered offenders will then be discussed. This section will highlight the pressures on the Criminal Justice System (CJS) and the way that it has become, in many cases, a de facto provider of mental health care. The argument that deinstitutionalisation has led to the ‘criminalisation of the mentally ill’ will be discussed. The legacy of deinstitutionalisation and the expansion of the penal state will be discussed, focusing on contemporary issues in the CJS.

The problem of definition

What do we mean by the term ‘mentally disordered offender’? At first, this appears a straightforward question: surely it is an offender who has committed offences as a result of the symptoms of mental illness. However, further consideration reveals that the complexities of the debates in this field. A very narrow definition of the term might limit its use to those who had been convicted and sentenced under the provisions of the Mental Health Act (1983). This is actually a very small group indeed. Such a definition would exclude important areas where the CJS and mental health systems intersect.