Quality of life among opiate-dependent individuals: A review of the literature.

Quality of life (QoL) has become an important outcome indicator in health care evaluation. A clear distinction has to be made between QoL - focussing on individuals' subjective satisfaction with life as a whole and different life domains - and health-related QoL (HRQoL), which refers to the absence of pathology. As opiate dependence is the primary drug of most persons entering treatment and as the attention for QoL in addiction research is growing, this review of the literature intends to summarise and differentiate the available information on QoL in opiate-dependent individuals. A comprehensive literature review was conducted, including database searches in Web of Science, Pubmed and Cochrane Database of Systematic Reviews. Articles were eligible for review if they assessed QoL or HRQoL of opiate-dependent individuals, used a QoL or HRQoL instrument and reported at least one specific outcome on QoL or HRQoL. In total, 38 articles have been selected. The review showed that various instruments (n=15) were used to measure QoL, mostly HRQoL instruments. Opiate-dependent individuals report low (HR)QoL compared with the general population and people with various medical illnesses. Generally, participation in substitution treatment had a positive effect on individuals' (HR)QoL, but long-term effects remain unclear. Psychological problems, older age and excessive alcohol use seem to be related with lower (HR)QoL scores. The assessment of QoL in research on opiate dependence is still in its infancy. Still, the chronic nature of drug use problems creates the necessity to look at outcomes beyond the direct consequences of drug dependence and based on clients' needs. HRQoL, with its unilateral focus on the functional status of clients, does not give information on clients' own experiences about the goodness of life, and is as a consequence unsuitable for measuring QoL. Future research starting from a subjective, multidimensional approach of the concept of QoL is required.