The inability of a person suffering from a mental disorder to refuse to consent to a sexual activity, because of an irrational fear arising from that disorder that prevented the exercise of choice, could amount to a lack of capacity for “any other reason” under the Sexual Offences Act 2003 s.30(2)(a). An inability to refuse included, under s.30(2)(b), an inability to communicate that choice as a result of or for a reason related to a mental disorder.

[2009] UKHL 42