Mental Illness in UK Law

It is subject to many cross-currents such as partiality, prejudice, self-interest and, above all, imagination and inaccuracy. Those are matters with which the jury, helped by cross-examination and common-sense, must do their best. But when a witness through physical (in which I include mental) disease or abnormality is not capable of giving a true or reliable account to the jury, it must surely be allowable for medical science to reveal this vital hidden fact to them.

It suffices for present purposes to say that, in my judgment, the authorities to which I have referred demonstrate that the inherent jurisdiction can be exercised in relation to a vulnerable adult who, even if not incapacitated by mental disorder or mental illness, is, or is reasonably believed to be, either (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.

The cause may be, but is not for this purpose limited to, mental disorder or mental illness. A vulnerable adult who does not suffer from any kind of mental incapacity may nonetheless be entitled to the protection of the inherent jurisdiction if he is, or is reasonably believed to be, incapacitated from making the relevant decision by reason of such things as constraint, coercion, undue influence or other vitiating factors.

Yet an anxiety neurosis or a reactive depression may be recognisable psychiatric illnesses, with or without psychosomatic symptoms. So, the first hurdle which a plaintiff claiming damages of the kind in question must surmount is to establish that he is suffering, not merely grief, distress or any other normal emotion, but a positive psychiatric illness.

First, physical illness or injury not brought about by a chain of demonstrable physical events but by mental or emotional stresses i.e. by a psychiatric route. In this case, the end product is a physical condition although it has been brought about by a process which is not demonstrably a physical one but lies in the mental or nervous system. The second form is psychiatric illness itself which is brought about by mental or emotional stresses i.e. by a psychiatric route.

In considering that wider question the matters to which a judge will invariably have to have regard to include (1) the extent to which the offender needs treatment for the mental disorder from which the offender suffers, (2) the extent to which the offending is attributable to the mental disorder, (3) the extent to which punishment is required and (4) the protection of the public including the regime for deciding release and the regime after release.

These passages lead to the reflection that it is possible that every mental illness may, in time, be shown to be accompanied by and consequent upon some change to the physical structure of the body, so that mental illness can properly be described as a type of physical injury.