In what circumstances can consent be considered valid if a patient has impaired capacity due to mental health issues?

Consent can be considered valid in patients with impaired capacity due to mental health issues if the patient is able to make the specific decision at the time it needs to be made, despite their condition. Under the Mental Capacity Act 2005, capacity is decision-specific and a person is assumed to have capacity unless it is proven otherwise on the balance of probabilities. A lack of capacity must be due to an impairment or disturbance in the functioning of the mind or brain that prevents the person from understanding, retaining, using or weighing information relevant to the decision, or communicating their decision. Importantly, all practicable steps must be taken to support the person to make the decision before concluding they lack capacity. The decision must not be judged invalid simply because it is perceived as unwise or risky by the practitioner. Furthermore, capacity assessments should be thorough, collaborative, and consider communication needs, and should not rely solely on tools not designed for capacity assessment. If the patient lacks capacity, consent may be given by a legally authorised person or under appropriate legal frameworks such as the Mental Health Act 1983/2007. Advance care planning and joint crisis planning may also be used to support decision-making in patients with mental health disorders at risk of relapse or deterioration.