Criminal Minds: Neuromodulation of the Psychopathic Brain

Although the definition of criminal behavior is fraught with controversy, with single acts “criminalized” or “decriminalized” according to time and place, and as such being observed in individuals of all sorts, there seems to be an agreement across the board that the truly dangerous subjects are psychopaths and the subjects affected by the Antisocial Personality Disorder (Janowsky, 2008), often repeat offenders. Psychopaths exhibit callousness, lack of empathy or emotional depth, and lack of genuine remorse for their antisocial actions. Although distinct in many regards, a subset of paraphilic subjects too can become dangerous, for instance those suffering sexual sadism, which may involve killing of the victim. Axis II personality disorder (APD) is thought to be among the most treatment refractory of DSM APDs. Overall, there is little evidence that drugs are reliably effective, and the same conclusion applies to many psychotherapies (Glenn and Raine, 2013). Prognosis appears to be poor, despite psychological, or drug therapy (Balon and Segraves, 2008). Although hypnosis can manipulate moral judgments (Whetley and Haidt, 2005), this modality has proved too erratic in criminal behavior reconditioning. The advent of in vivo neuroimaging allowed the dissection of brain regions involved in such dysfunctions. A wide range of brain areas has been implicated, including the frontal cortex [dorsolateral prefrontal cortex (DLPFC), ventromedial/orbitofrontal cortex (VMPFC/OFC), and the amygdala]. Structural abnormalities include reduced prefrontal gray matter in APD and psychopaths (e.g., Yang et al., 2005; Baron-Cohen, 2011). Importantly, imaging data point to a difference between APD and psychopathy, in that the former have poor impulse control (DLPFC dysfunction), whereas the latter have lack of empathy (non-underactive DLPFC) (Greene, 2009; Baron-Cohen, 2011). So-called ablative functional neurosurgery, whereby irreversible brain lesions are achieved by various means, has been employed mostly in the past to treat such patients. Sano and Mayanagi (1988) submitted to stereotactic posterior hypothalamotomy, a series of 60 children with violent, aggressive behavior, and a history of epileptic seizures and mental retardation, with good long-term control in many. Other authors reported similar results in this group of patients (e.g., Ramamurthi, 1988). Stereotactic amygdalotomy too has been applied since 1961 for the treatment of severe aggressive behavior, with improvement varying between 33 and 100%, many in the long term (Mpakopoulou et al., 2008). Dieckmann et al. (1988) reported excellent results for the control of aggressive sexual behavior with hypothalamotomy, although the pedophilic character of such patients was retained (see also Roeder, 1966). Unfortunately, stereotactic neurosurgery is associated with a mortality rate which, according to the depth of penetration of the surgical probes, is not trivial. Thus, it cannot be offered on a routine basis. Deep brain stimulation (DBS), a reversible, stimulatory technique whereby electrodes are inserted deep into the brain in a targeted fashion, has emerged as a viable option for the treatment of neurological and psychiatric disorders, including aggressive behavior (Arle and Shils, 2011). A report described limbic DBS for intermittent explosive disorder (Maley et al., 2010) and others exist. Even for drug addiction – which often leads to criminal behavior, both ablative and modulatory neurosurgery have been employed with initial promising results (Stelten et al., 2008). Heath (1964) already experimented with septal DBS in psychiatric subjects in order to engage “pleasure” circuits with an eye to preemptive “mind control” of aberrant behaviors. Unfortunately, DBS too carries a small risk of mortality (roughly 0.4%) and disabling morbidity (roughly 1%) (Arle and Shils, 2011). It is my contention that a strong case can be made for the experimental application of cortical neuromodulation as applied to the control of psychopaths and repeat offenders. This is a risk free, zero-mortality, and zero-morbidity neuromodulatory technique (Canavero, 2009). It modulates the excitability/activity of cortical and related sub-cortical networks involved in pathophysiological disorders, including those of psychiatric classification.