Increasing research interest is focussing also on Quality of Life (QoL) in substance dependent individuals. QoL-assessments have been acknowledged as promising measurements in order to evaluate drug treatment programs.

A prospective, randomized, double-blind, double-dummy, cross-over study design was used in order to compare methadone and slow-release morphine maintenance on patients´ QoL. Sixty-four participants were randomized between two treatment groups receiving either slow-release morphine capsules for 7 weeks followed by methadone oral solution for another 7 weeks (group A), or vice versa (group B). At baseline, week 7 and week 14 QoL status was evaluated using the German version of the Lancashire Quality of Life Profile.

A significant time effect with respect to the domains: general state of health (0.018), mental health (p=0.001), general well-being (p<0.001), leisure time at home (p=0.032) and leisure time out of home (p=0.008). Our findings did not show any statistically significant differences between between the two treatment groups in any Quality of Life scores at week 7 and 14. At the end of study phase (week 14) group A showed significant increases in the domains general well-being (0.010), leisure time at home (p=0.014). Significant improvements for group B were assessed with regard to general well-being (p=0.003), mental health (p=0.003) and general state of health (p=0.017).

The development of treatment programs should focus also on the patients´ subjective perspective. According to our findings agonistic opioid maintenance treatment yields not only to treatment response but also to improvements in patients quality of life.