In 2005, the Medical Treatment and Supervision Act (the MTS Act) was enacted in Japan to hospitalize the criminally insane and to promote a self-supporting lifestyle after deinstitutionalization. as of October 2011, about 500 patients remain hospitalized in highly secure forensic hospitals. the increased prevalence of the combination of criminal insanity with alcohol or volatile organic solvents dependence is a serious issue, as it may be an obstacle for treatment and rehabilitation after discharge because alcohol or the paint thinner can be easily purchased everywhere. On the other hand, as presented at EPA meeting in 2011, we established a strategy that can maintain patients in a well-adjusted condition in the community through comprehensive and supportive activities by a multidisciplinary team comprising staff members of the hospital, the public health center, and other local municipal officials. This strategy named as maintaining involvement is performed inside the hospital first and then in the community after discharge and, consequently, patients can live in the community without treatment interruption or repetition of similar criminal acts. Therefore, we used this strategy for the patients with drug dependence because they are often deteriorated by treatment interruption. the aim of this treatment is that patients can maintain the insight into drug dependence. as a result, patients who have been successfully de-institutionalized lead a self-supporting lifestyle without treatment interruption or symptoms of drug dependence. We believe that maintaining involvement is an effective method for the treatment of the criminally insane with drug dependence.