This is a research thesis for the degree of PhD in Nursing of the University of Nairobi. The study was conducted in the city of Nairobi at two study sites that provide institutionalized care for psychoactive substance dependent patients. The aim of the study was to innovate and implement/ test a nursing intervention model for the care of institutionalized psychoactive substance dependent patients. The study was started in 2009 and ended in 2011.