Fitness to plead: Development and validation of a standardised assessment instrument

Prevalence of mental disorders in defendants at criminal court

BACKGROUND

Psychiatric morbidity in prisons and police custody is well established, but little is known about individuals attending criminal court. There is international concern that vulnerable defendants are not identified, undermining their right to a fair trial.

AIMS

To explore the prevalence of a wide range of mental disorders in criminal defendants and estimate the proportion likely to be unfit to plead.

METHOD

We employed two-stage screening methodology to estimate the prevalence of mental illness, neurodevelopmental disorders and unfitness to plead, in 3322 criminal defendants in South London. Sampling was stratified according to whether defendants attended court from the community or custody. Face-to-face interviews, using diagnostic instruments and assessments of fitness to plead, were administered (n = 503). Post-stratification probability weighting provided estimates of the overall prevalence of mental disorders and unfitness to plead.

RESULTS

Mental disorder was more common in those attending court from custody, with 48.5% having at least one psychiatric diagnosis compared with 20.3% from the community. Suicidality was frequently reported (weighted prevalence 71.2%; 95% CI 64.2-77.3). Only 16.7% of participants from custody and 4.6% from the community were referred to the liaison and diversion team; 2.1% (1.1-4.0) of defendants were estimated to be unfit to plead, with a further 3.2% (1.9-5.3) deemed 'borderline unfit'.

CONCLUSIONS

The prevalence of mental illness and neurodevelopmental disorders in defendants is high. Many are at risk of being unfit to plead and require additional support at court, yet are not identified by existing services. Our evidence challenges policy makers and healthcare providers to ensure that vulnerable defendants are adequately supported at court.

Characteristics and re-offending outcomes of 'limiting-term' forensic patients found unfit to stand trial in New South Wales, Australia

There are little published data on the characteristics or outcomes of offenders found unfit to stand trial who receive a 'qualified finding of guilt' in a Special Hearing in New South Wales (NSW) and are detained for a 'limiting term' (LT) under the supervision of the NSW Mental Health Review Tribunal (MHRT). We examined NSW MHRT records linked to re-offending data, to report on the characteristics and outcomes of 69 LT patients in a cohort spanning two decades. The most common diagnoses were schizophrenia (54%) and intellectual disability (33%). Patients were detained on average for 4.2 years, which is slightly shorter than the average maximum term imposed. Of the 55 people for whom criminal record data were available, 9.1% were charged with an offence during the first year post-release and 60% overall were charged for at least one post-release offence during a follow-up period ranging from 4.7 to 11.1 years.

The Use of Neuroscience and Psychological Measurement in England's Court of Protection

The 2005 Mental Capacity Act of England and Wales provides a description in statute law of a test determining if a person lacks "mental capacity" to take a particular decision and describes how the "best interests" of such a person should be determined. The Act established a new Court of Protection (CoP) to hear cases related to the Act and to rule on disputes over mental capacity. The court gathers a range of evidence, including reports from clinicians and experts. Human rights organisations and others have raised concerns about the nature of assessments for incapacity, including the role of brain investigations and psychometric tests. Aim: Describe use and interpretation of structured measures of psychological and brain function in CoP cases, to facilitate standardisation and improvement of practices, both in the courtroom and in non-legal settings. Method: Quantitative review of case law using all CoP judgments published until 2019. The judgments (n = 408) were read to generate a subset referring to structured testing (n = 50). These were then examined in detail to extract the nature of the measurements, circumstances of their use and features of interpretation by the court. Results: The 408 judgments contained 146 references to structured measurement of psychological or brain function, spread over 50 cases. 120/146 (82.2%) referred to "impairment of mind or brain," with this being part of assessment for incapacity in 58/146 (39.7%). Measurement referred on 25/146 (17.1%) occasions to "functional decision-making abilities." Structured measures were used most commonly by psychiatrists and psychologists. Psychological measurements comprised 66.4% of measures. Neuroimaging and electrophysiology were presented for diagnostic purposes only. A small number of behavioural measures were used for people with disorders of consciousness. When assessing incapacity, IQ and the Mini-Mental-State Examination were the commonest measures. A standardised measure of mental capacity itself was employed just once. Judges rarely integrated measurements in their capacity determinations. Conclusion: Structured testing of brain and psychological function is used in limited ways in the Court of Protection. Whilst there are challenges in creating measures of capacity, we highlight an opportunity for the neuroscience community to improve objectivity in assessment, inside and outside the courtroom.

Reforming fitness to plead and stand trial legislation in England and Wales

The legal decision on whether a defendant can fairly take part in a criminal trial in England and Wales is currently based on the leading case of R v Pritchard (1836), which despite subsequent case law updates does not embrace the concept of mental capacity or effectively identify defendants who are unable to meaningfully participate. Further to an extensive consultation process, the Law Commission published recommendations for reform in 2016, with a proposed new test of capacity to participate effectively in a trial and detailed suggestions for statutory reform of court procedures for managing defendants found unable to participate. Here we review the proposals and consider practical implications and suggestions regarding their implementation.

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Meta-analysis of second generation competency to stand trial assessment measures: Preliminary findings

BACKGROUND

Since the 1990s, standardized competency to stand trial assessment measures have been developed to improve the reliability and validity of expert assessment and opinion in legal settings. This study aimed to meta-analyze the psychometric properties of the four 'second generation' assessment tools: the MacCAT-CA, MacCAT-FP, ECST-R and CAST*MR.

METHOD

A systematic search of published and unpublished studies was undertaken on PsycNet, PubMed, Scopus, Web of Science and Science Direct up until February 2018. Test manuals were sourced and attempts at finding grey literature included contacting study authors and test developers.

RESULTS

Eleven studies were included in the final analysis. The MacCAT-CA, ECST-R and CAST*MR demonstrated acceptable subscale internal consistencies and interrater reliability. The MacCAT-CA and CAST*MR discriminated between competent and incompetent defendants with large effects. The MacCAT-FP had insufficient reliability data and poor discrimination. There was insufficient data to meta-analyze the factor structure, sensitivity, specificity, or effect sizes between types of clinical presentation on any tool.

CONCLUSIONS

Very few studies have investigated the psychometric properties of the selected tools. Many studies were excluded for not providing original data or simply re-reporting the psychometric properties stated in test manuals. Whilst the MacCAT-CA and ECST-R have promising psychometric properties, ongoing construct validation is required.