1. Custom has established six months as the minimum and nine months as the ideal period of treatment for drug addicts admitted to the U. S. Public Health Service Hospital in Lexington, Ky.2. The minimum standard has been justified, to a certain extent, by investigations carried on at the hospital which reveal that drug addicts do not regain complete physiological normality for approximately six months after withdrawal from drugs.3. Follow-up studies made on 335 patients who were admitted to the hospital during the fiscal year, 1936-37, fail to show any statistically significant relationship between the duration of treatment and the efficacy of treatment.Abstract Teaser