Participants

We performed a cross-sectional study based in three general adult acute psychiatric wards (one female and two male) at the Maudsley Hospital, London, UK. These wards serve part of Southwark, a deprived inner-London borough with an ethnically diverse population. The local research ethics committee approved the study.

Consecutive patients, admitted between February 2006 and June 2007, were identified by regular examination of the electronic medical records and consultations with the ward nursing staff. All admissions were included other than those admitted during planned research breaks. The sole exclusions were people from other catchment areas admitted to the wards and those transferred from other in-patient facilities. All individuals who spoke English were approached for a research interview. Those who assented were provided with full details of the study and the interview was stopped if there was any subsequent change in choice or resistance. Written consent was sought and participants were offered £5 for their time. Interviews were conducted as close to the admission as possible.

Assessment of capacity

Relevant information about the participant's presenting problems, diagnosis and treatment plan was obtained from the medical record and discussion with the clinical team. The clinical researcher (G.O.) determined whether the treating team's principal treatment recommendation at that time was stabilisation on medication or admission to a place of safety (hospitalisation). If it was medication, then the capacity assessment centred on the decision to take the recommended medication or not. If it was hospitalisation, then it was the capacity to decide on whether to come into hospital or not.

The presence or absence of capacity to decide on treatment was based on the two-stage test formulated in the Mental Capacity Act. This requires: evidence of ‘an impairment of, or disturbance in, the functioning of the mind or brain’ (Section 2(1)); and evidence that this impairment or disturbance means that the person is unable to make a specific decision (Section 3(1)). We interpreted the first stage of the test using clinical psychopathological concepts and ICD–10 diagnoses. ⁸

The capacity judgement was facilitated by a clinical assessment (notes review and clinical interview) and the administration of the MacArthur Competence Assessment Tool for Treatment (MacCAT–T). ^{Reference Grisso, Appelbaum and Hill-Fotouhi9} The MacCAT–T is a semi-structured interview that provides relevant information disclosures to individuals about their illness (including its risks), the nature of treatment options and their risks and benefits. The assessor evaluates capacity in terms of four abilities relating to the disclosures: understanding, appreciation, reasoning and expressing a choice. These abilities map onto the abilities regarded as relevant by the Mental Capacity Act which are understanding, retaining, using, weighing and communicating. ‘Using’ is the term the Law Commission favoured in place of the term ‘appreciation’. ¹⁰ We interpreted the terms to have equivalent meanings.

The judgement about capacity followed the approach outlined by Grisso & Appelbaum. ^{Reference Grisso and Appelbaum11} This incorporates the ‘sliding scale’ concept whereby decisions that carry a greater risk require greater evidence of the relevant decision-making abilities. This concept is similar to the English Law notion that the graver the consequences of the decision, the commensurately greater the level of competence that is required to make it.

The content of the MacCAT–T was modified for this study. When the principal treatment decision concerned medication, participants were given a disclosure about ‘no medication’ as the alternative to the ‘recommended’ medication rather than iterate through all medication options. This was done to simplify the interview and to reflect the main choice people who are acutely ill typically face. When the principal treatment decision concerned hospitalisation, participants were given a disclosure about the option of being an in-patient or not. Each disclosure involved giving the individual simple information about the nature of the option and its risks and benefits. The form of the MacCAT–T was left unaltered by these changes. Previous studies have demonstrated excellent interrater reliability (κ>08) when the MacCAT–T is used in this way. ^{Reference Okai, Owen, McGuire, Singh, Churchill and Hotopf12,Reference Cairns, Maddock, Buchanan, David, Hayward and Richardson13}

Other variables

Details of status under the Mental Health Act were obtained from the clinical records. The Expanded Schedule for the Assessment of Insight (SAI–E) ^{Reference Sanz, Constable, Lopez-Ibor, Kemp and David14} and the Brief Psychiatric Rating Scale (BPRS) ^{Reference Ventura, Green, Shaner and Liberman15} were also administered. Both are clinically based, semi-structured interviews. The SAI–E comprises three main dimensions (awareness of illness, relabelling of symptoms as pathological and treatment adherence). We used the summary of adherence score (Item C of the SAI–E) as our measure of treatment refusal. This is a seven-point scale: 1 = complete rejection of treatment; 2 = partial rejection; 3 = reluctant acceptance; 4 = occasional reluctance; 5 = passive acceptance; 6 = moderate participation; 7 = active participation. We used the relabelling score because it has conceptual similarity with ‘use’ (in the Mental Capacity Act). This scale measures the extent to which symptoms that the clinical interview has highlighted as indicators of illness can be regarded as such by the patient. We separated relabelling from treatment refusal because they are conceptually distinguishable. We adjusted the total BPRS score to account for domains of psychopathology that were not assessable (e.g. hallucinations in an individual who was mute) by summing subscores and dividing the total by the number of BPRS domains that were assessable. This was done to obtain a measure of total symptoms that was not misleadingly low in participants who did not respond to questions about symptoms. Level of symptoms is sometimes used with ‘insight’ to interpret ‘nature and degree’ (in the Mental Health Act). Broad ICD–10 categories were used for the main mental disorder.

We recorded acts of self-harm and violence in the period 2 weeks prior to admission until the point of assessment using information from the medical records, nursing staff and self-report. To structure this we used the Modified Overt Aggression Scale. ^{Reference Kay, Wolkenfeld and Murrill16}

We used the MacArthur Admissions Experience Survey ^{Reference Gardner, Hoge, Bennett, Roth, Lidz and Monahan17} to collect information relating to subjective coercion. This relates to recent admission and includes measures of participants' perceived coercion, recall of negative pressures and sense of ‘voice’ in the admission procedure.

Statistical analysis

Analyses were performed using Stata 9.2 for Windows. Conventional bivariate methods were used to compare participant groups.

Main findings

People admitted to psychiatric hospital from the community span all four groups created by capacity law and the Mental Health Act: capacity/informal, incapacity/informal, capacity/detained and incapacity/detained. The largest groups are capacity/informal (37%) and incapacity/detained (34%). Approximately a third fell into the legally and ethically more problematic categories of incapacity/informal and capacity/detained. Of these, the incapacity/informal group was large, comprising 24% of the sample. Most people in this group have a psychotic illness or depression as the main mental disorder, a pattern similar to that of the detained/incapacity group. With regard to the provision of treatment to this incapacity/informal group the principles of the Mental Capacity Act will now apply, thus any treatment given will have to be in the person's best interests and be the least restrictive alternative. However, if this treatment involves deprivation of liberty under article 5, European Convention on Human Rights, then a choice will have to be made between detention under the Mental Health Act and the application of the deprivation of liberty safeguards under the amended Mental Capacity Act. Thus, in relation to this significant group of individuals, clinicians will have to become familiar with the identification of deprivations of liberty and with the factors governing the choice of legislative framework, including the person's objections to treatment. In relation to the presence of ‘objection’, the data indicate that informal patients without capacity have higher levels of treatment refusal, perceived coercion and negative treatment pressures on admission and a reduced sense of ‘voice’ compared with informal patients with capacity. The majority of people in this group have levels of treatment refusal between occasional reluctance and moderate participation. If any level of treatment adherence less than ‘passive acceptance’ is taken as a marker for ‘objecting’ to treatment then incapacity associates with ‘objection’ in informal patients. Such a level of objection might amount to grounds for preferring Mental Health Act detention to deprivation of liberty under the Mental Capacity Act. This could lead to an increase in the use of the Mental Health Act in relation to previously informal patients who are deprived of their liberty. Much will depend on how ‘deprivation of liberty’ and ‘objecting’ to treatment are interpreted by clinicians and ultimately by the courts – both will become significant legal concepts yet both pose challenges of interpretation.

The capacity/detained group was small (6%). About a third probably lacked capacity at the time of admission but had recovered it by the time of interview. Most are on assessment sections of the Mental Health Act. Surprisingly, participants in this group did not feel more coerced than those without capacity who are detained. They were less symptomatic and better able to relabel their symptoms as pathological, an important aspect of insight. ^{Reference David19} They self-harmed more but were neither more nor less violent. In some cases, previous risky behaviour in someone whose further intentions were not clear was a key factor. There have been human rights concerns about detaining individuals with capacity. ^20,21 It might be expected that this group would be characterised less by psychotic illness, and more by people with personality disorders posing considerable risk of harming themselves or others. In this study over half of these individuals had psychotic illnesses as the main diagnosis, and none had personality disorder as the main diagnosis. However, the sample size for these analyses was small, making it difficult to draw firm conclusions. Further, it is possible that the existence of this group simply reflects a few inevitable ‘false negative’ errors in the capacity classification (or ‘false positive’ errors in the application of the Mental Health Act).

Which factors are associated with detention on admission to psychiatric hospital? We found that irrespective of capacity, treatment refusal rather than recent violence or self-harm was most strongly associated with detention. This suggests that it is the perceived need for treatment by the clinical team in the face of resistance from the individual that drives detention under the Mental Health Act rather than recent self-harm or violence. The only positive association of detention in participants with capacity is treatment refusal. Relabelling of symptoms did not associate with detention in this group. Although recent self-harm or violence were not associated with detention for the group as a whole, it was important for a subgroup of people where it was difficult to assess the individual's intentions in respect of a repetition of self-harm or violence. The associations of detention in people without capacity go beyond treatment refusal and include recent violence and inability to relabel symptoms. This suggests that in clinical practice the significance of recent violence depends upon capacity status and the related concept of ability to relabel symptoms as pathological. When capacity is absent, recent violence seems more likely to trigger detention than when capacity is present.

Methodological shortcomings

This is the largest study of mental capacity in a psychiatric setting yet conducted, although as the study was carried out in an urban setting in one jurisdiction it may not generalise to other psychiatric in-patient settings. Previous studies were limited by the use of convenience samples or not including an overall judgement of capacity for a clinically significant decision. ^{Reference Sanz, Constable, Lopez-Ibor, Kemp and David14} We used a strictly consecutive sample and expanded treatment decisions to include hospitalisation if this was the significant treatment decision. Fifty-seven per cent of all admissions participated in the assessment by the researcher. This raises the issue of non-participation potentially creating a non-representative sample. Our comparisons of non-participants and participants on basic clinical and legal variables suggested that the participants were reasonably representative of the individuals admitted.

Our assessments of capacity were not carried out at the precise time of the clinical decision to admit the person to hospital. The majority were carried out within 3 days. This time lag could be a problem for missing rapidly fluctuating capacity status but we believe that this is only likely to be a major factor in the setting of emotional crises (e.g. surrounding self-harm), or drug or alcohol intoxication. The majority of individuals who were admitted had psychotic or serious affective illnesses that are unlikely to involve significant capacity fluctuation over the course of a few days.

Clinical and legal implications

Clinicians now face a more complex landscape of mental health law. They will have to navigate two legal frameworks, the Mental Health Act 1983 and the Mental Capacity Act 2005, and keep in mind the unfolding meaning of ‘deprivation of liberty’ and ‘objecting’ to treatment. This study maps existing psychiatric practice onto this more complex legal landscape to show us some of the implications. However, it was not able to resolve the question of how prevalent ‘deprivation of liberty’ is in the in-patient setting.

Although systematic study of the practice of mental health law inevitably requires attention to specific jurisdictions (in this case England and Wales) we think this study helps to illuminate relationships between mental health law and guardianship/incapacity law existing across many jurisdictions in the developed world. How these dual legal frameworks will affect psychiatric practice itself over time is yet to be seen.

Criteria for detention in hospital under the Mental Health Act 1983 (as amended by the Mental Health Act 2007)

A person can be detained for assessment under section 2 only if both the following criteria apply:

1. (a) the person is suffering from a mental disorder of a nature or degree which warrants their detention in hospital for assessment (or for assessment followed by treatment) for at least a limited period; and

2. (b) the person ought to be so detained in the interests of their own health or safety or with a view to the protection of others.

A person can be detained for treatment under section 3 only if all the following criteria apply:

1. (a) the person is suffering from a mental disorder of a nature or degree which makes it appropriate for them to receive medical treatment in hospital;

2. (b) it is necessary for the health or safety of the person or for the protection of other persons that they should receive such treatment and it cannot be provided unless the patient is detained under this section; and

3. (c) appropriate medical treatment is available.

Department of Health. Code of Practice Mental Health Act 1983: 24. TSO (The Stationery Office), 2008.