Mental capacity and psychiatric admission

Abstract

Many patients lack capacity to consent to treatment on admission, but not all qualify for treatment under the Mental Capacity Act

When the Mental Capacity Act 2005 and the Mental Health Act 2007 are fully implemented in England and Wales over the next year, both will be available to authorise a person’s psychiatric treatment without consent. The two acts are based, however, on different legal standards.¹ The Mental Capacity Act may be used only when a person lacks the capacity to consent. The Mental Health Act, in contrast, can be used regardless of a person’s capacity to consent, if the act’s different criteria of mental disorder, risk of harm, availability of treatment, and so on, apply. Nevertheless, a person can be covered by both acts at the same time, in which case clinicians would have to choose which one to apply.²

In their linked study, Owen and colleagues throw some light on the frequency with which this choice between legal options will arise.³ In a study of 350 consecutive admissions to psychiatric care in inner city London, they found that 86% of patients admitted under the Mental Health Act lacked capacity to consent to treatment on entry to hospital. This finding indicates that a considerable proportion of these patients would also meet the criteria for cover by the Mental Capacity Act. Thirty nine per cent of patients informally admitted also lacked capacity, as did 60% of those admitted overall.

The 60% prevalence of incapacity found in the group overall is higher than that usually seen in samples of general psychiatric inpatients—22-45% is more common.⁴ This might be because Owen and colleagues assessed patients’ capacity close to the time of admission, when rates of incapacity are likely to be high. They also found particularly high rates of incapacity in patients with schizophrenia and mania, and much lower rates in those with depression or personality disorder. Many patients with these last two diagnoses, who retained their capacity, would not be eligible for treatment under the Mental Capacity Act.

Two recent reviews of the characteristics of patients who lack capacity help us put these findings into context.^{4 5} As might be expected, incapacity to consent is often associated with psychosis,^{4 5 6 7} severity of symptoms,^{4 5} lack of insight,⁶ involuntary status,^{4 5} treatment refusal,^{4 5} and older age.⁷ Specific risk factors include a diagnosis of schizophrenia,^{7 8} mania,⁶ Alzheimer’s disease or other dementias,⁷ the presence of delusions,⁶ and other measures of neuropsychological or cognitive dysfunction.^{9 10} No consistent association has been found with educational level or social class, or with sex or ethnicity once other variables are controlled.⁴

A considerable proportion of informally admitted psychiatric inpatients lack capacity,^{4 5} as is true of patients in general medical wards,⁷ particularly very old patients and those with acute conditions.⁷ In one London study, 40% of general medical inpatients lacked capacity, a similar proportion to that found among informal psychiatric admissions in Owen and colleagues’ study.⁷

The reliability of the process of assessing capacity can be substantially improved by training clinicians,^{5 11 12} and by using standardised instruments like the MacArthur competency assessment tools.^{5 12} Repeated communication of information can improve patients’ understanding, which promotes their capacity,⁵ and many swiftly recover their capacity after treatment.⁵

The important finding of Owen and colleagues’ study—that a high proportion of patients admitted under the Mental Health Act lacked the capacity to consent to treatment at the time of admission—does not tell us precisely how many might have been lawfully treated under the Mental Capacity Act, however. This is because, for the Mental Capacity Act to apply, further legal criteria—beyond the capacity test—must also be met. Notably, the patient must not be refusing treatment, and the care proposed must be in the patient’s best interests.¹ Many patients admitted under the Mental Health Act would be refusing treatment, and others might not be admitted primarily in their own interests but to protect others. The Mental Capacity Act would then not apply. Only by measuring patients against all the criteria for cover established by the Mental Capacity Act could we accurately assess the proportion of patients who would be eligible for treatment under that act.

Owen and colleagues focused on patients’ capacity at the time of admission to hospital. They did not assess whether patients lacked capacity later in the process—a month later, for instance, when they might be discharged to supervised treatment in the community. Many sectioned patients will recover their capacity after their initial treatment, or their capacity might fluctuate. If incapacity principles were strictly applied, such patients would have to be swiftly released from involuntary treatment whenever they regained their capacity, an outcome that might preclude the provision of sustained treatment.

So, even though some patients will meet the legal criteria for treatment under both acts at the time of admission to hospital, practitioners dealing with patients with fluctuating mental conditions might prefer to rely on the authority of the Mental Health Act when convinced that the patient needs a sustained programme of care.

Cite this as: BMJ 2008;337:a116