Objective: According to obvious changes in drug abuse patterns in recent years, the main purpose of this study was to reassess the effect of demographic and other individual factors on the drug treatment process

Materials & Methods: In this analytic-descriptive study, data collected in Tehran’s Welfare Organization drug treatment outpatient clinics (both private and non-private clinics). 8 clinics were selected (based on a triage classification of clinics, according to the quality of services registered in governmental experts’ records) Demographic and individual variables extracted from the1372 existing files in the treatment centers. Then data processed by multivariable logistic regression.

Results: In this study 258 records (18.8%) of patients revealed successful completion of detoxification phase , The final multiple regression model’s results showed that :1- Crack user clients had 1.49 times more unsuccessful detoxification, (P=0.5), 2- Clients with drug use frequency once daily showed 2.4 times more successful completion in drug detoxification than users with the frequency of 4 times a day, (P=0.01), 3- Also clients with drug free close relatives and home mates had 1.8 times more succession in drug detoxification (P<0.01) and 4- Crack user patients presented with psychological or somatic signs and symptoms had 1.94 times more succession in treatment than others without these symptoms.

Conclusion: New patterns of drug use reveal the importance of reassessing the effect of demographic factors and severity and depth of drug use on the treatment process (as well as quality assurance of services).