The voluntary in-patient / residential drug rehabilitation programmes, run by the Caritas - Hong Kong, the Society for the Aid and Rehabilitation Abusers (SARDA), the Hong Kong Christian Service and Christian therapeutic agencies, cater for the needs of those drug dependant persons who wish voluntarily to seek residential treatment, rehabilitation and social reintegration. Since drug abusers from varying background have different needs for treatment and rehabilitation services, a range of programmes using different treatment models have been developed.