15/03/2016 10:42 GMT | Updated 16/03/2017 05:12 GMT

The Government's Pledge to Give Mental Health 'Parity of Esteem' Means That the Law Needs to Change

This week saw the inaugural Mental Capacity Action Day, which laudably seeks to increase awareness of the Mental Capacity Act. It is also an excellent point to reflect on mental health legislation more broadly, and especially how current legislation interfaces both with the concept of 'mental capacity' (in other words the ability to understand, retain and weigh information to make a specific decision about something, and then to communicate that decision) and with the buzzwords in mental health at the moment, which are undeniably 'parity of esteem' (the principle that mental health should be valued as much as physical health).

Everyone agrees that parity is important (the three main political parties have publicly nailed their colours to its mast) but then stumbles over what it actually means in practice. Does it mean that we should simply treat both with respect, and not discriminate against one or the other? This is easy to say, but difficult to measure. Does it mean that we give literally the same amount of money to both? This is also easy to say, but misses the point - some treatments for mental illness cost more - and many less - than equally effective treatments for physical illness.

The Royal College of Psychiatrists and the British Medical Association have both made good efforts at defining what parity of esteem actually means. But one area that has so far been excluded from discussion is mental health law itself. That could be about to change, as the recently published report from NHS England's influential Mental Health Taskforce called for mental health legislation to be reviewed.

So what could revised mental health law look like? A good place to start is the issue of coercion - without doubt the most controversial element of the existing law. A novel approach to start thinking about this is to consider the law about coercive treatment for physical illness. What would happen if someone has a particularly nasty and infectious disease, or has been exposed to a dangerous amount of radiation for example? Well, as for mental illness, if they are willing to be treated then the question of coercion doesn't arise. And in most cases, it's quite hard to imagine someone turning down medical help in such circumstances. But what if they did? Under the Public Health Act 1984, in certain circumstances a magistrate can order an infected/contaminated person to be taken to hospital and detained there. Many countries have similar provisions - few Americans will remember "Typhoid Mary" but at one time she was almost a catchphrase. So you can be detained against your will both for certain physical as well as mental illnesses (in some circumstances) - parity of detention if you wish. But that's where the parity ends. You can be detained but you cannot be treated for an infectious disease, or if you've been contaminated by radiation. This follows from legal cases which have repeatedly made it clear that - as far as physical health goes - an individual with mental capacity should have the autonomy to refuse even life-saving treatment if they so wish (even if the doctors disagree with their reasons). There is even a case (Re C) that established that someone with a mental illness shouldn't automatically be presumed to not have the capacity to make a decision about refusing life-saving treatment for a physical illness. This case was tremendously important - but didn't affect the fact that someone with mental illness can be both detained and also treated against their will for that mental illness, even if they have the mental capacity to make an informed decision about the treatment. Additionally, coercive measures taken under the Public Health Act can only be taken if there is a risk to others, whereas mental health legislation can be used if there is either a risk to others or just to the individual themselves.

This difference is logically unsustainable - if the law accepts the principle that an adult with a physical illness who has the mental capacity to make a decision should have the right to refuse even life-saving treatment if their own health (but not others) is imperilled, then why should this not be the case for someone with a mental illness in comparable circumstances who has the capacity to make that decision? Just to be clear, neither of us suggests this should necessarily be the case for people who pose a risk to others - although that is certainly a topic for another day.

A parity approach is certainly helpful for stimulating discussion, but we would caution against accepting the physical health legal provisions uncritically. In fact, there are even a couple of areas where the Public Health Act could learn from mental health legislation. For example, failing to comply with the former can land someone with a fine of up to £20,000, which seems heavy-handed (there is no such fining system under mental health law). Furthermore, although the maximum period that someone can initially be detained under the Public Health Act is much shorter than the Mental Health Act equivalent (28 days as opposed to six months), the mechanism to extend it is just for a new application to go to potentially the same magistrate, meaning that the Mental Health Act's safeguards of providing tribunals (with lay members) and doctors to give a second opinion are arguably more robust.

Parity of esteem is a good slogan. Reforming the law to give people with capacity the right to refuse compulsive treatment for mental illness, even though doing so might make their own health worse, will be a key test of whether the government is serious about making parity happen. Change will take time, but the government must start thinking about whether it wants parity in practice, or is content for it to remain just a good sound-bite.