The Law Commission published their comprehensive review of current fitness to plead provisions in 2011 and recommendations on the issue are expected later this year. ¹ Notwithstanding the regularity with which reports addressing the issue of fitness to plead are requested of psychiatrists, there remains a lack of clarity on the subject. The legal test still derives from a case in 1836 (R v Prichard) ² and there is general agreement among psychiatrists and legal professionals that the presently accepted requirements are far from adequate. Whereas these ‘Prichard criteria’ broadly set out the requirement for the accused to be able to enter a plea, understand the evidence against them, instruct their solicitor, follow court proceedings, and challenge a juror, in many cases it is far from clear what threshold these requirements are measured against.

To what extent does a mild intellectual disability or autism-spectrum disorder render someone unfit to plead or stand trial? We know that rates of intellectual disability are relatively high in convicted offenders; does that mean most of them are to be considered legally unfit? Is that actually in the interests of justice or the individual? Although arguably it is for the court to decide, a great deal of weight is often placed on the expert witness report and it falls to the psychiatrist to consider these questions. Efforts have been made to introduce a standardised test for fitness to plead, ^{Reference Akinkunmi3} yet none has been universally accepted. It is incumbent on courts to adopt special measures to assist vulnerable defendants to participate in proceedings; if such measures can be considered sufficient for children, does this extend to adults?

The rationale for the provisions under Prichard is to protect the vulnerable and avoid subjecting those with mental disorder to unjust criminal justice proceedings which they cannot understand or fully participate in. Where an accused is deemed unable to do any one of these then he or she should be considered unfit to plead and can be dealt with under the Criminal Procedure (Insanity and Unfitness to Plead) Act 1991, usually by holding a trial of the facts and then, if convicted, considering disposal options such as a hospital order, supervision or an absolute discharge.

The fundamental principle of an individual's right to defend themselves should not be undermined without proper consideration. On the other hand, many professionals are of the opinion that the current system sets too high a threshold with the result that too few mentally disordered offenders are found unfit to plead. ^{Reference Rogers, Blackwood, Farnham, Pickup and Watts4} In the USA, around 10% of offenders are considered to ‘lack competence to stand’, but in England and Wales that figure is much lower. ¹ One of the reasons for this is that, strictly speaking, the current criteria focus almost exclusively on cognitive ability rather than decision-making capacity, with little account being paid to suggestibility, memory impairment, the ability to give evidence in court, the impact of psychosis or of cultural barriers.

In their report, the Law Commission propose a new legal test much more closely aligned with the capacity test recently enshrined in the Mental Capacity Act 2005. ¹ Under the new provisions an accused would need to demonstrate that they understood the information relevant to the decisions that he or she would have to make in the course of the trial, retain that information, use or weigh that information as part of the decision-making process and communicate his or her decisions. Such a test should be acceptable to psychiatrists, as it simplifies the requirements and largely mirrors the capacity test with which we are all now familiar. However, such a change could have significant cost and resource implications. The new system could see many more people assessed by psychiatrists and any corresponding increase in compulsory admissions could have a significant impact on forensic services, although the cost might be offset by a reduced number of custodial sentences. The Law Commission's final recommendations, expected later this year, are anticipated with great interest.