Forensic psychiatry and risk assessment

Published on 24/05/2015 by admin

Last modified 22/04/2025

Print this page

This article have been viewed 1884 times

CHAPTER 18 Forensic psychiatry and risk assessment

Forensic psychiatry is the specialty which deals with the interface between law and mental health. Thus, forensic psychiatrists work in prisons, community clinics and secure hospitals. They may give evidence in court or be involved in advising lawyers and judges on the relationship between psychiatric disorder and legal issues such as offending, compensation and decision-making capacity. This involves the assessment and treatment of a range of different conditions, the provision of medico-legal reports and the giving of evidence in courts and tribunals.

The core skills of a forensic psychiatrist are not inherently different from those of the general adult psychiatrist (or in some situations, child and adolescent or old age psychiatrist): what differs is an understanding of the legal and ethical context in which their skills are used. In addition, some specialised areas of practice may be developed (e.g. in the assessment and management of sexual offenders).

Areas of work for the forensic psychiatrist

Civil arena

Many forensic psychiatrists work in the private sector and provide medico-legal opinions, predominantly relating to civil matters. These include insurance—mainly workers’ compensation and traffic accidents—as well as providing psychiatric reports for other jurisdictions such as professional registration boards.

There are a range of psychiatric consequences which may develop from workplace or traffic accidents (see Box 18.1). But moreover, premorbid personality and mental disorder may affect the development of psychiatric illness, and forensic psychiatrists are involved in assisting the trier of fact (court, tribunal or insurer) to determine what was preexisting and what someone else is liable for.

Children and family

Issues of child sexual abuse, neglected children and psychiatric issues related to the breakdown of relationships are the specialty of some forensic psychiatrists, often with child and adolescent psychiatric training, who provide opinions to assist the court in determining how to regulate relationship breakdowns and look after the welfare of children.

Criminal jurisdictions

Most people think of forensic psychiatrists as working in criminal jurisdictions. In these areas, forensic mental health services are involved in many stages of the care of mentally disordered offenders. Such offenders may be diverted from police custody into psychiatric units. The prevalence of mental disorder in people remanded in custody is greatly increased compared to the general community, as is the proportion of people with troublesome substance use. Court liaison services assess and divert some mentally disordered offenders.

Once imprisoned, mental disorders are assessed and managed by forensic mental health staff, although it should be noted that compulsory treatment is not permitted in prisons. Overall, well over half of all people remanded in custody have significant substance abuse problems; personality disorders are massively increased; and the prevalence of psychotic illnesses is approximately eight times that of the general population and possibly more for women. In the United States, some prisons have so many mentally disordered people that they qualify as the largest psychiatric institutions in the country.

Some people with mental disorders are not able to be managed in the prison system. Typically, they have severe mental health problems and refuse treatment. Most mental health legislation provides for the involuntary transfer of prisoners to secure psychiatric facilities for treatment.

Secure psychiatric units

Secure units are classified as high, medium and low secure. High secure units generally have a perimeter wall and complex security arrangements, including biometric scanning, registration of visitors, and a range of processes to maintain security in the unit. Medium secure units may not have a perimeter wall, but are locked. Low secure units do not provide the same level of security and are used for patients who have community access, although with conditions.

Secure psychiatric units are designed to meet the treatment and rehabilitation needs of mentally disordered offenders who may pose a significant risk to the community. The length of stay is much longer than in general psychiatric units, and staffing levels are often much higher.

The courts and fitness to plead

The expert opinions of forensic psychiatrists, giving evidence in court and being available to be examined and cross-examined by barristers, is integral to the use of so-called mental state defences.

When a person is considered to have offended while mentally ill, legal systems take this into account. In some cases there exist insanity or mental impairment provisions, which enable a person to be found ‘not guilty by reason of insanity’ or to be similarly acquitted, if at the time of offending their mental disorder interfered grossly with their reasoning. However, despite acquittal, the person is likely to be detained thereafter in hospital or subject to treatment provisions to reduce the risk to the community.

At the stage of a trial, some accused people are psychiatrically unwell or have significant cognitive impairment, which prevents them from fairly participating in a trial. When the question is raised, the court may engage in a formal process to determine whether or not the person is fit to stand trial. This involves assessment, expert evidence and a determination of whether or not the person is able to understand and follow legal proceedings. In the event that they are not, the person may be directed to remain in prison or hospital for an indefinite term: the trial does not proceed.

CASE EXAMPLE: fitness to plead

A 52-year-old man was charged with sexual offences against his children, alleged to have occurred 10 years previously. Since then he had been in a car accident and sustained a severe brain injury. A recent neuropsychological assessment demonstrated impairments of memory and attention, and significant frontal lobe injury. The injury was documented and the cognitive assessment was consistent with neuroimaging scans.

Both the prosecution and defence arranged forensic psychiatrist assessments. The psychiatrists reviewed the documentation, assessed the defendant and provided reports to court. Instead of hearing the criminal allegations, the court conducted a special hearing into the issue of fitness to be tried. Both psychiatrists gave evidence and were cross-examined in front of a jury. They stated that his brain injury meant that he could not understand the evidence and would not be able to follow a trial or instruct his lawyer in order to participate meaningfully in a trial. The jury found that he was not fit to be tried. As a result, no criminal trial proceeded, and he returned to live in a residential facility in the community, with conditions of psychiatric supervision.

Risk assessment

Forensic mental health expertise is frequently used in the prediction of risk, the management of high-risk patients, and formal assessments of people who might pose a risk. Risk assessment is integrated with risk management, as there is little benefit in defining risk without determining how to intervene to diminish it.

Risk can be defined as the likelihood of a chosen outcome. In forensic practice, the likelihood is strongly associated with the outcome of concern. For example, an exhibitionist may expose himself to hundreds of women, but the harm may not be significant, whereas a single episode of penetrative sexual abuse against a child is more likely to have significant and lasting consequences. Thus, the risk posed by the latter offender is much greater.

Schizophrenia is associated with violent offending, although for some years this association was discounted. Rates of violence are 2–5 times greater, and of homicide are around tenfold increased. Some violence is situational and difficult to predict. It is, however, clear that associated substance abuse and specific difficult personality traits may amplify this risk. Certain specific symptoms or behaviours may accentuate risk in schizophrenia: these are shown in Box 18.2.

BOX 18.2 Particular risk markers in schizophrenia

Risk markers include:

• persecutory delusions that a person is under threat

• passivity phenomena (the experience that one’s thoughts, actions or moods are taken over by others)

• delusional jealousy, and

• delusional beliefs specifically targeted upon one individual.

Risk factors are static or dynamic. The former consist of historical or demographic variables such as gender or a history of serious violence. The factors are immutable, although other counterfactual factors may alter the risk. For example, a man with a long history of violence who is 60 and has had a stroke may register as high risk on historical analysis, but the counterfactual element of a severe physical disability reduces his ability to be aggressive.

Dynamic risk factors are changeable variables. Some are rapidly variable, such as intoxication; others act over the longer term, such as unstable accommodation.

Risk assessment involves a variety of methods, including:

clinical judgment

actuarial prediction

adjusted actuarial assessment, and

structured professional judgment.

Historically, risk assessment was conflated with dangerousness prediction. At that time, the prevailing thought was that violence was inherently unpredictable, and not strongly associated with psychotic illness. In addition, dangerousness was described as a trait inherent to certain individuals, rather than the effect of a range of different factors pertaining to an individual.

Clinical judgment of risk may be unstructured, involving intuition or ‘clinical experience’. However, research has demonstrated that clinical judgment is rarely better than chance at predicting which patients will act violently.

In some cases, clinical judgment includes a functional analysis of behaviour (see Box 18.3). This permits an examination of the problem behaviour or historical event, and will generate both hypotheses about the behaviour and ideas about how best to reduce its recurrence.

BOX 18.3 Functional analysis of behaviours: A–B–C

Functional analysis comprises clinical judgments about:

• A Antecedent thoughts, emotions and circumstances

• B the actual concerning Behaviours, and

• C consideration of the Consequences of the behaviour and their effects on the protagonist.

Actuarial prediction has focused upon analysing data about past violent offenders to generate probabilistic algorithms and translate them into useful instruments to predict future risk. The evidence from large surveys supports the improved prediction characteristics of actuarial instruments. Adjusted actuarial assessment involves modifying the result of actuarial prediction by considering idiosyncratic features of the individual being assessed and tweaking the result accordingly.

More recently, these have been combined with the current preferred approach to risk assessment: structured professional judgment. This involves the use of (preferably multiple) empirically derived risk assessment instruments which address both static and dynamic risk factors. The ratings obtained from these instruments are used in subsequent case-specific modification of the resultant risk estimate, to reflect the individual characteristics of the specific person (as the risk instruments are based upon categories or groups, rather than the unique characteristics of the specific offender being considered). The structured professional judgment method is currentbest practice in risk assessment.

Risk assessment instruments

Risk assessment instruments have a variety of acronym-based names. The most commonly used is the HCR–20 (Box 18.4), which is a structured instrument to predict violence based on historical, clinical and risk variables spread across 20 domains. It is reliable, valid and easy to use. Each item is marked 0, 1 or 2 (corresponding to absent, partially present or uncertain, and definitely present). The score is less important than the spread of scores, and the HCR–20 presents targets for intervention which may reduce risk.