Aggressiveness has a high prevalence in the psychiatry population and is of major concern. Though pharmacological treatments are effective for most patients, there is a portion that doesn't respond properly and is considered medically refractory. For them, surgical procedures (i.e. stereotactic lesions) have been performed as an attempt to reintegrate patient into society. The amygdala is a main structure in the control of aggressive behavior and amygdala lesion could improve behavior without neurological or other behavioral impairment. In this study, it will evaluate the functional results of the bilateral amygdala lesion of aggressive refractory patients through neuroimaging, clinical assessment and blood hormonal levels. To better understand the neurobiology of aggression, aggressive patients that are not refractory will also be studied through neuroimaging and hormonal levels.

Inclusion Criteria:

• Refractory aggression (Adler et al., 2015) defined by extreme levels of aggression after the use of Risperidone or Aripiprazole ou combination of others psychoactive drugs.

Exclusion Criteria:

• Patients with anatomical alterations that may disrupt the surgery, infections or non-controlled diseases, treatment with other experimental drugs, pregnant women or during lactation, psychological or sociological conditions that will not permit the patient to be accompanied by the medical staff.

Refractory aggressive patients.