Results indicate that if aggression control therapy was provided as designed, it met most conditions for treatment integrity. Although originally intended for adult inpatients with an antisocial personality disorder, the therapy appears applicable to adolescents with an oppositional-defiant conduct disorder and adult outpatients with an antisocial personality disorder. Patients are excluded from participating in cases of acute psychosis, acute substance abuse, insufficient knowledge of the Dutch language, and an inability to participate in a group. Aggression control therapy can reduce the aggressive behavior of violent forensic psychiatric patients to some extent. However, there are indications that in its current form, aggression control therapy is especially beneficial for patients with a relatively low score on psychopathy. These patients often exhibit reactive aggressive behavior because they have limited emotional control and social skills deficits. During the character formation module, patients are not only confronted with the negative consequences of proactive aggression but also with the positive consequences of prosocial behavior. The purpose of the prosocial thinking styles module is to change criminogenic antisocial attitudes into prosocial attitudes. For patients with a long-lasting antisocial personality disorder, the therapy has a treatment program for dynamic criminogenic needs, such as drug dependency, inability to function adequately in intimate relationships, lack of adequate parental education, and ambient factors such as limited education, unemployment, and antisocial friends. For inpatients, booster sessions during the extramural resocialization need to be part of such a program to check whether or not the patient can adequately apply what he has learned outside of the hospital. It should be noted that dropout rates for outpatients is high, despite the many measures to stimulate their participation. Table, note, references