Addiction is a brain disease, and it doesn't matter: How the aetiology of neurological impairment guides Magistrates’ perceptions of criminal responsibility

This thesis investigates the extent to which addiction and its associated neurobiological impairment are considered as factors in Magistrates' criminal sentencing decisions. Over four empirical studies, Magistrates were presented with sentencing scenarios and their decisions analyzed. Study 1 indicated that addiction can be treated as a disease of the mind, but only in the explicit absence of choice in its initiation. Where normative addiction narratives were confounded by removing choice, leniency was extended in common with similar impairment of alternate origin. This choice component was examined in the context of age of first drug use, maintenance of addiction, and the extent to which addiction might undermine perceptions of intoxication being voluntary. Study 2 found that choice was equivalently inculpating whether made as a juvenile or an adult, but leniency was observed where addiction was accompanied by an acquired (fictional) brain disease, suggesting it was not solely drug-use which set it apart. In Study 3, removing choice from addiction promoted leniency, but only where drug-use was ongoing and uninterrupted. Where it was not, removing choice resulted in harsher sentencing. Study 4 examined addiction as it influenced perceptions of choice in intoxication, finding that, in specific circumstances, intoxication could serve to mitigate, whilst addiction was more commonly seen as aggravating, even in the absence of intoxication. Results are discussed in relation to current legal standards which attach criminal responsibility to acts on the basis of volitional control over behaviour and deny excuse to offenders where they are understood to have created the circumstances of their own defence. These findings demonstrate impairment mediating leniency on the basis of its aetiology. Addiction is understood as a brain disease in theory, but is treated so in practice only where conventional aetiological narratives are confounded by varying perceptions of voluntariness in drug-use