The Introduction summarises the core themes of the book and outlines how the argument will proceed over the course of its chapters. It explains why the issue it centres around – namely, how the law grapples with the impact of mental disorder on decision-making – is so important, and why successfully navigating the tension between respect for (and deference to) idiosyncratic values, and protection from disorder or impairment, must be a precondition of England and Wales adopting ‘fused’ mental capacity and health legislation, or a more CRPD-compliant statutory framework. It also explains how the book relates to the existing literature in this area, which has focused in recent years on concerns about the binary nature of the capacity framework, and on the individualistic and rational ‘liberal subject’ on which this framework rests. Finally, it elaborates briefly on some of the concepts which the book will draw upon, in particular what is meant by ‘values’ and ‘beliefs’.

Where the real basis for finding someone to lack capacity is that you consider the beliefs or values that motivate their decision to be distorted by a mental illness, such that the decision is not authentically desired and so is unworthy of respect, this entails a number of empirical and normative claims. This chapter will interrogate these claims by reference to the wide-ranging literature on the nature of mental disorder, and on differing conceptions of autonomy and authenticity (as a component of autonomous decision-making). It will be concluded that while an agent acting on the basis of disordered beliefs or values will often be acting inauthentically (and thus non-autonomously), this will not always be the case, and situations could arise in which there is reason to believe that the agent would endorse or sanction their belief, even knowing it is derived from illness. Moreover, once the shaky conceptual ground on which such judgements must be made is acknowledged, it becomes essential that these judgements are brought out into the open, where they can be subject to appropriate scrutiny.

This chapter will explore a key problem with the current law’s approach – namely, that it is impossible to assess a person’s capacity to ‘use or weigh’ the information relevant to a decision without engaging with the values that underpin their decision. It will suggest that while some recourse to the person’s values is unavoidable, the current approach gives assessors ample room to invoke other values when assessing the person’s capacity, thus creating space for paternalistic judgments to go unchecked. Despite this risk, it will be claimed that in many of the cases in which this occurs, underpinning the assessment is in fact a concern that the values or beliefs that motivate a person’s decision have been affected by an illness or impairment, such that the decision reached is not one that the agent would have made, but for that disorder or impairment. The current law cannot account for this, and so assessors are forced to manipulate the test for capacity instead. While this prevents unnecessary harm, it has the effect of obscuring the value-laden and highly controversial claims that may underpin such decisions, which remain insulated from scrutiny or challenge.

Violence is common and is a public health issue. Forensic psychiatrists offer treatment for the small amount of violence that is due to mental disorder. It is essential to distinguish between meaningful explanations and causes. Violence is not a unitary concept. Evidence for the specific causal associations between mental illness and violence is reviewed. Anger, anxiety, moral and amoral actions are reviewed including intoxication and withdrawal, deception, antisocial personality and psychopathy, and a range of mental illnesses and developmental disorders. Social and developmental factors are also important. Memes, media and social contagion influence the forms of violence. Court reports and treatments are considered critically in relation to violence.

This chapter describes some commonly used nonhuman paradigms for assessing animal behavior and the figures that are used to present those data. The chapter opens with an overview of some animal species used in neuroscience research, a discussion about nonhuman housing, and a description of types of validity that behavioral neuroscientists concern themselves with. The behavioral tests described here are divided into five major categories: motor behaviors; pain; learning and memory; mental disorders such as anxiety, depression, and substance use disorder; and social behaviors. Included is a description of a survival analysis and an explanation of interpreting Kaplan–Meier curves.

This chapter seeks to provide clinicians with a better understanding of prisons and overcome many of the myths and misconceptions, with the objective of making the environment more attractive and interesting for future psychiatrists. In addition to a wide need and a rich variety of conditions, the psychiatrist in prison must contend with barriers to care such as working without a mental health act and, when a patient needs to be transferred and treated outside of prison, navigating complicated pathways to care. Mental disorder is prevalent in all prison systems. Pathways into prison may be related to general factors, specific factors such as delusions and comorbidities and complications of mental illness such as homelessness and breakdown of relationships, as well as service provision issues. The prevailing policy has been to divert prisoners in need of hospital care out of prisons. Court diversion models can focus on any point in the pathway from community to the criminal justice system. In prison, specialist mental health services are needed to address the high levels of morbidity due to self-harm, drug use, suicide and self-harm, hunger strikes and many other manifestations of developmental problems and traumatic experiences.

This chapter reviews decision-making in insanity defense trials. The chapter begins with an overview of the variety of legal definitions of insanity in the United States, discussing how these rules provide parameters and shape (or fail to shape) insanity decisions. Various factors related to decision-making in insanity defense cases are discussed, including attitudes toward the insanity defense itself (and how these reflect myths about the insanity defense and its implications), prototypes of insanity, and individual differences of both jurors and defendants. The chapter examines misconceptions of mental disorder and how these might relate to decision-making in these cases and considers the role of decision-makers’ perceptions of punishment in this context. The chapter also reflects on the role of intersecting identities in insanity judgments, provides an overview and synthesis of the current body of research on legal decision-making in insanity cases, discusses limitations to the current literature, provides future directions, and considers legal and policy implications.

Violence is more common in prisons than in the community. Mental disorders are over-represented in this population, and are associated with an even higher risk of perpetrating or becoming a victim of prison violence. Violence in this environment has unique characteristics, strongly influenced by gangs and an illicit economy. This chapter reviews the causes and management of prison violence, and the role of the mental health clinician in the assessment and management of violence in prison relating to mental disorder. The early impact of COVID-19 on prison violence is described.

The potential negative effects of exercise addiction (EA) were first reported over 50 years ago, but it has only recently been formally recognized as a disorder in the leading clinical manuals. The inclusion of exercise behaviour as a potentially addictive behaviour will require greater consensus on how to define this disorder, with diagnostic criteria and course descriptions clearly supported by scientific evidence, and on how to categorize it in relation to other mental disorders. This chapter presents an overview of attempts to identify the defining features of EA, the development of instruments to measure it, estimates of its prevalence, and the main strategies for treating it. The diverse terminology used to describe this disorder reflects both the range of perspectives from which it has been examined, and the different manifestations of EA. The chapter concludes by recognizing that the development and validation of specific diagnostic criteria for EA pose many challenges.

Irrational beliefs are often associated with poor mental health and are seen as costly beliefs that should be eliminated or replaced when possible. Building on decades of empirical research, we argue that irrational beliefs are widespread in human cognition and not confined to people with poor mental health. Moreover, recent philosophical research has emphasized that irrational beliefs can be beneficial to the person holding them, not only psychologically but also epistemically, which suggests that in some cases elimination or replacement is not the most appropriate course of action. The problem emerging is how we decide when an agent’s irrational belief needs to be challenged: in this chapter, we point to the importance of the social context surrounding the agent by discussing one case of everyday confabulation whose effects vary across contexts.