A program centering on group work therapy has curtailed the recidivism rate among sex offenders as measured against those who served time but didn’t participate, the Justice Ministry said.

“A certain degree of effect has been observed,” the ministry said Friday in releasing its first report on the program’s impact.

Offenders incarcerated for sex crimes such as rape and indecent assault and who were judged likely to repeat were picked to take part in the program. Introduced in 2006 at selected prisons and probation centers nationwide, it took cues from similar initiatives introduced in Canada and the United Kingdom, according to the ministry.

Based on cognitive behavioral therapy designed to make subjects aware of problems in their thought patterns, the program involves group discussions about why participants committed their crimes. The participants were also required to work out plans for their future lives after being released.

Taking the program is mandatory by law except for those who are ill, being disciplined or deemed incapable of participating in group activities.

The research checked recidivism over a three-year period for 1,198 program participants and 949 nonparticipants released from prison between January 2007 and December 2011. For those who were freed less than three years earlier, the ministry used estimates.

Among nonparticipants, 29.6 percent were arrested or subject to other law-enforcement measures for crimes including sex offenses, compared with 21.9 percent among the participants.

For rape, the recidivism rate was 19.4 percent for nonparticipants and 11.9 percent for participants, the survey found.

Clinical psychologist Sayoko Nobuta, who is familiar with sex offense cases, noted the recidivism rate was lower than anticipated and said the ministry deserves credit. But she also said there’s room for improvement.

“The current sex offender handling program has brought in what is done overseas, and it has to be revamped to suit conditions in Japan,” Nobuta said. “The program also has to be fine-tuned, such as changing guidance based on participants’ intelligence levels.”