Drunk, dangerous and delusional: how legal concept-creep risks overcriminalization

In the recent case of R v. Taj, the Court of Appeal of England and Wales upheld the conviction of a defendant who, in a psychotic delusional state, mistook his non-threatening victim to be a terrorist, violently attacking him. The law typically allows honest mistakes (even if unreasonable) as a basis for self-defence (in this case the defence of others). However, because Taj's delusions were found by the court to have been caused by voluntary alcohol consumption, special legal (prior-fault) intoxication rules were applied to block his defence; Taj was convicted and sentenced to 19 years imprisonment for attempted murder.

We focus here on the simple question-what does it mean to be intoxicated? On the facts, Taj did not have drugs active in his system at the time of the attack, but the court nonetheless insisted that Taj's delusional mistake was 'attributable to intoxication'; namely, to drink- and drug-taking in the previous days and weeks. This extended conception of intoxication was questionably distinguished from psychosis induced by withdrawal. Furthermore, the court was unreceptive to evidence of a long-standing, underlying mental health disorder. We argue that the court's expanded view of intoxication is problematic, in that intoxication-induced psychosis cannot be sharply distinguished from other causes such as mental disorders; and even if it could be distinguished, it should not give rise to blame and punishment in the same way as does conduct induced by chemically active intoxicants ('drug-on-board').

The courts' expansion of the definition of intoxication is both legally and forensically problematic, introducing legal vagaries where the clinical science is already vague; and with intoxication frequently interlocking with historic intoxication and secondary or comorbid mental health conditions, the decision risks inappropriately and/or over-criminalizing defendants.