GAO's examination of the research literature found 22 reviews of the effectiveness of treatment programs for sex offenders. The reviews discussed both treatment effectiveness and methodological adequacy. There was no consensus among the reviews as to what treatment works to reduce the recidivism of sex offenders. The cognitive-behavioral approach was most often cited as promising, particularly with child molesters and exhibitionists. Because of methodological limitations in the studies, however, a quantitative estimate of the impact of cognitive-behavioral treatment on recidivism was not attempted in these reviews. Psychotherapy was generally viewed as ineffective except, in some cases, when administered in combination with another treatment approach. Nearly all the reviews reported that definitive conclusions could not be drawn because methodological weaknesses in the research made inferences about what works uncertain. There was no consensus that more and better research was needed to demonstrate the effectiveness of sex offender treatment.