پرخاشگری، اختلالات فکری و روانی و تصویربرداری مغزی؛ نقد و بررسی و توصیه آینده

Violent behavior appears to result from a complex web of interacting genetic as well as environmental factors. Psychopathy is a strong predictor for relapse in violent acts. The current review shed light on rapidly expanding knowledge in brain imaging related to violent behavior and psychopathy. A literature search was performed in PubMed, Cochrane and PsycInfo combining the key words: mentally disordered offender/aggression/violence/ crime/forensic psychiatry/brain imaging neuroimaging/fMRI/MRI/PET/SPECT/lack of empathy/psychopathy and antisocial personality disorder. The reviewed material, which consisted of 48 articles, indicates a rather strong consensus on the connection between dysfunctional parts of the frontal and temporal lobes and violent antisocial behavior and psychopathy. In future studies, it would be useful to focus on the limbic system and to investigate which parts of the frontal lobes and cerebral networks that are of interest in the psychopathic personality. Moreover, the reviewed material highlights some of the methodological difficulties in this area of research such as selection bias in the recruitment of patients, inadequate matching of control subjects, and sometimes incongruous results. In the future we hope that brain imaging can be used to map biological deviations in different offenders in order to try to learn more about the different mechanisms behind violent behaviors.

Earlier studies have pointed to a complex web of biological and social risk factors underlying antisocial and violent behavior (Raine, 2002). Whether these risk factors eventually lead to antisocial and violent behavior in any single individual depends on a large set of possible interactions, which are still largely in need of further research (Raine, 2002). Specific traits in the personality may, regardless of diagnosis, be related to violent behavior. Accordingly, there are different motives and different triggers for violent behavior such as hatred, jealousy, perceived insult, fantasy, distortions of reality or the urge to gain money or dominance. Despite a strong consensus on the complex causes of violent behavior, general psychiatry and forensic psychiatry are often limited to referring violent behavior to specific psychiatric diagnoses defined in the diagnostic manual DSM-IV (American Psychiatric Association, 1994 and American Psychiatric Association, 2000). According to DSM-IV, subjects have to fulfill a number of criteria in order to receive a certain diagnosis, and even then, two subjects assigned the same diagnosis could present very differently, since they may not share the same criteria. To illustrate this; in order to be assigned the diagnosis Borderline Personality Disorder (BPD), a subject has to fulfill five out of nine different criteria. In practice therefore, two BPD patients may only really share one of the specified criteria. Therefore, it would probably be more interesting to consider functional differences, such as intentions and motives that control and trigger different types of offenders. Such differences could be explored with regards to factors such as impulse control and lack of empathy. Criminal investigative analyses (Hazelwood and Warren, 2000 and Meloy, 2000) and case studies (Kristiansson, 1995), have already suggested differences in motives and triggers underlying violent behavior.