Table 1.

Summary of treatment outcome studies for psychopathy and violence.

Study	Population	Sample sizea	Gender	Primary treatment orientation	Outcome measures	Post-treatment follow-up period (in months)b	Results
Abracen et al. (2011)	Sex offender	119	Male	CBT	Sexual violent recidivism	M = 122.7	There was no effect of treatment for PSY or non-PSY groups.
Barbaree (2005)	Sex offender	224	Male	CBT	Sexual & nonsexual violent recidivism	M = 62 (1–120)	PSY predicted sexual and nonsexual violent recidivism at significantly higher rates.
Caldwell, Skeem, et al. (2006),	Adolescent	141	Male	Behavioral	Nonsexual violent recidivism	24	High PSY adolescents treated at the MJTC were significantly less likely to violently recidivate than high PSY adolescents in TAU.
Caldwell (2011)	Adolescent	248	Male	Behavioral	Nonsexual violent recidivism	M = 54 (24–79)	High PSY adolescents treated at the MJTC were significantly less likely to violently recidivate than high PSY adolescents in TAU.
Caldwell et al. (2007)	Adolescent	86	Male	Behavioral	Nonsexual violent recidivism	M = 50.6 (3–83.5)	No relation between PSY and violent recidivism at follow-up.
Chakhssi et al. (2010)	Forensic psychiatric	74	Male	CBT	Institutional violence	No post-treatment follow-up. However violence was measured in 6 month increments for 18 months as treatment was ongoing.	Approximately 25% of PSY became more violent while most showed no change in violence.
Gretton et al. (2001)	Adolescent sex offender	264	Male	Not specified	Sexual & nonsexual violent recidivism	M = 55 (7–106)	PSY predicted sexual and nonsexual violent recidivism at significantly higher and faster rates.
Hildebrand et al. (2004)	Psychiatric sex offender	94	Male	CBT	Sexual & nonsexual violent recidivism	M = 141.6 (21.6–282)	PSY predicted sexual and nonsexual violent recidivism at significantly higher and faster rates.
Langton et al. (2006)	Sex offender	571	Male	CBT	Sexual & nonsexual violent recidivism, treatment dropout	M 70.8 (<1–140.4)	PSY predicted treatment dropout, sexual and nonsexual violent recidivism, and faster failure rates for violent recidivism.
Looman et al. (2005)	Sex offender	154	Male	CBT	Sexual & nonsexual violent recidivism	Median was approximately 5 years, specific data not reported	PSY predicted sexual and nonsexual violent recidivism at significantly higher and faster rates.
Olver and Wong (2006, 2009)	Sex offender	156	Male	CBT	Sexual & nonsexual violent recidivism, treatment dropout	M = 118.8 (25.2–216)	PSY predicted treatment dropout, sexual and nonsexual violent recidivism, and faster failure rates for violent recidivism.
Olver et al. (2013)	General forensic	152	Male	CBT	Nonsexual violent recidivism, change in violence risk scores	M = 58.8	PSY predicted less change in violence risk scores and higher rates of violent recidivism.
Richards et al. (2003)	General forensic	404	Female	CBT	Institutional violence	M = 14	PSY was associated with violence prior to and during treatment, but was not associated with violence rates post-treatment.
Rice et al. (1992)	Forensic psychiatric	322	Male	Therapeutic community	Nonsexual violent recidivism	M = 126	Violent recidivism for treated PSY was significantly higher than for untreated PSY.
Seto and Barbaree (1999)	Sex offender	216	Male	CBT	Sexual & nonsexual violent recidivism	M = 32 (1.3–81)	High PSY men with better treatment behavior were more likely to recidivate with sexual or nonsexual violence.
Skeem et al. (2002)	Community psychiatric	195	Not specified	Multiplec	Self & collateral reported violent behavior	No post-treatment follow-up. However, violence was measured in 10 week increments for 12 months as treatment was ongoing.	More persons in high PSY group receiving 7+ sessions were violent than persons in high PSY group receiving 0–6 sessions at first follow-up, but no differences at remaining 4 follow-ups.
Spain et al. (2004)	Adolescent (50% sex offenders)	85	Male	REBT	Institutional violence	No post-treatment follow-up	PSY predicted higher rates of violent incidents during treatment program.

Note. PSY = Psychopathy; CBT = Cognitive Behavioral Therapy; REBT = Rational Emotive Behavior Therapy; MJTC = Mendota Juvenile Treatment Center; TAU = Treatment as Usual Comparison Group.

^aNumbers reflect total sample prior to attrition or exclusion from analyses for missing data.

^bThere was no uniform method of reporting for these data across studies; for ease of comparison we converted all data to time in months when sufficient information was provided. Where available we report means and ranges of follow-up periods in parentheses.

^cThere was no uniform treatment program or modality of treatment of patients in this study.