In law, the capacity to make a specific decision has a binary quality. Somewhat like a light it is either on or off, you either have it or you don’t and there are no intermediate states. Yes capacity can fluctuate, the bulb can wink on and off, but at any one time we either have the ability to make a specific decision or we do not. For strong liberty promoting reasons, the law is jealous of the right of adults to make decisions. This is reflected in the legislation around incapacity: it imposes an obligation on those assessing capacity to make all reasonable efforts to enhance it; the burden of proof of incapacity also falls on those who assert it.

In relation to medical decision making the possession of functional decision making capacity is only one of the requirements for informed consent. Voluntariness—the provision of consent free from coercion or undue influence is another. For some time now people working with vulnerable adults have been concerned about possible unintended consequences of incapacity legislation. Under the Mental Capacity Act (MCA), where adults are assessed as lacking decision making capacity, welfare promoting decisions can be made on their behalf. Where adults retain capacity but their ability to promote their own interests is seriously compromised—perhaps because they are being coerced—the MCA cannot be used and practitioners have felt powerless to intervene.

In England and Wales, before the introduction of the Mental Capacity Act (MCA), the High Court had the power to protect adults unable to promote their own interests, irrespective of their decision-making capacity. This power was based upon the Court’s inherent jurisdiction—a common law doctrine that states that a superior court has the jurisdiction to hear any question that comes before it, unless that power has been specifically limited by statute or rule.

The High Court’s inherent jurisdiction to the medical treatment of mentally incapacitated adults was established in the landmark case Re:F.  With the coming into force of the MCA, and the transferring of jurisdiction in relation to incapacitated adults to the Court of Protection, doubt arose about whether the inherent jurisdiction of the High Court survived in relation to vulnerable adults who retained capacity. A recent case in the Court of Appeal (A Local Authority and others v DL[2012] All ER (D) 2011 (Mar))  has nicely crystallised a series of common law developments relating to the scope of the inherent jurisdiction in these cases. The case involved an elderly couple living with their adult son. Following reports that he was being abusive, including allegations that he was trying to force them to put the house in his name, the local authority started proceedings with a view to protecting the couple. As neither had functional incapacity, the High Court first addressed itself to the question of whether it had inherent jurisdiction to hear the case, concluding that it did. The son appealed the decision and the Court of Appeal summed up the position as follows:

The Court’s inherent jurisdiction was targeted solely at those adults whose ability to make decisions for themselves had been compromised by matters other than those covered by the [Mental Capacity Act 2005]. The jurisdiction was, in part, aimed at enhancing or liberating the autonomy of a vulnerable adult whose autonomy had been compromised by a reason other than mental capacity because they were; (i) under constraint; or (ii) subject to coercion or undue influence; or (iii) for some other reason deprived of the capacity to make the relevant decision or disabled from making a free choice, or incapacitated or disabled from giving or expressing a real and genuine consent.

On the face of it the inherent jurisdiction could raise the spectre of judicial paternalism, granting the Court considerable powers to intervene in the lives of vulnerable adults. The Court of Appeal’s decision works however to restrict the scope of the jurisdiction to an autonomy promoting or defending role. A coerced decision is no more autonomous than an incapacitous one and surely no more deserving of respect.

The Mental Capacity Act is a principled piece of legislation, designed to protect the interests of a potentially very vulnerable group of individuals. It stretches credulity to imagine that the drafters had in mind the simultaneous removal of judicial protection from adults vulnerable to coercion by others. The resurrection of the inherent jurisdiction looks like a major step forward in the protection of vulnerable adults.

Julian Sheather is ethics manager, BMA. The views he expresses in his blog posts are entirely his own.