Personality Disorders and Responsibility: Learning from Peay

People with personality disorders should be treated fairly. Potential crime victims should be protected. That much is uncontroversial. The hard questions ask what is fair, when is protection adequate, and how should we achieve fairness and protection together. Peay outlines five main hurdles that the law must jump to reach these goals. All five raise serious challenges. To begin to address these challenges, we must first clarify what a personality disorder is.

The notion of a personality disorder is defined very broadly in DSM-IV-TR as any inflexible, pervasive, enduring, stable, and early-onset pattern of experience and behavior that deviates markedly from cultural expectations, leads to clinically significant distress or impairment, and is not an effect of a substance or another mental disorder or medical condition. This general definition includes many specific personality disorders, including paranoid, schizoid, schizotypal, conduct, antisocial, borderline, histrionic, narcissistic, avoidant, dependent, and obsessive–compulsive. These disorders vary widely in their associated mental states and behaviors.

The diversity within this category should make us wary of any broad generalizations about the class a whole. The best treatment for one personality disorder (such as obsessive–compulsive personality disorder) need not have much in common with the best treatment for the others (such as paranoid or antisocial personality disorder). Patients with one personality disorder might be responsible, whereas patients with a different personality disorder are not. At least, we should not assume that all personality disorders should be handled in the same way, either by psychiatrists or by the law.

Peay seems to focus mainly on antisocial personality disorder (DSM-IV-TR), but also mentions dangerous and severe personality disorder (Home Office and Department of Health, 1999), psychopathic disorder (Mental Health Act, 1983), and psychopathy (usually defined by Hare’s Psychotherapy Check List-Revised (PCL-R). These diagnoses differ in important ways. Some are psychiatric, whereas others are legal in their purposes and uses. They have varying degrees of scientific testing and validity. They also differ in coverage. In one sample from a medium-security prison in the United States, more than eighty percent of the prisoners met the DSM-IV-TR criteria for antisocial personality disorder, but fewer than twenty percent were diagnosed as psychopaths under the PCL-R (Kent Kiehl, personal communication).

Because these categories are so different, we need to specify which one is at issue. Most patients with antisocial personality disorder might respond to cognitive–behavioral therapy and might be responsible under legal and moral standards, even if the same does not hold for most true psychopaths. Some studies (Rice, Harris, and Cormier 1992) have found that some talk therapy actually increases the rate of recidivism in psychopaths! Moreover, many researchers distinguish subtypes of psychopathy, so different psychopaths might respond differently to different treatments and might also differ in their responsibility. This variety makes it impossible to justify precise answers to general questions like: Are people with personality disorder treatable or responsible? Are people with antisocial personality disorder treatable or responsible? Are psychopaths treatable or responsible?

To increase precision, I focus in what follows on the most uniform and best-studied diagnosis: psychopathy as defined by a score of thirty or higher on Hare’s PCL-R. This focus has the disadvantage of making the discussion less directly relevant to the law of the United Kingdom, but one must wonder whether the categories in UK law are what get in the way of reliable generalizations about the people we are trying to understand. It is also not clear whether true psychopathy defined by PCL-R score is a personality disorder or, instead, some other kind of mental illness.

Nonetheless, Peay’s five hurdles for the law apply to psychopaths in particular. At least, that is what I will try to suggest.

The first problem, according to Peay, is that the criminal law of excuses is too narrow, at least in England, Wales, and many of the United States. In these jurisdictions, a defendant can be found guilty when she knew what she was doing and also knew it was illegal, even if...