Multiple substance use among patients attending treatment for substance-related problems in Switzerland

The purpose of this paper is to estimate the share of multiple substance disorders among clients entering treatment for substance-related problems, to identify the most frequent combinations of the substances involved and to investigate the profiles of the clients involved.

Data were taken from the Swiss treatment monitoring system act-info applied among inpatient and outpatient facilities (reporting years 2013–2015). All cases with information on multiple substance disorders, according to a definition close to the diagnosis F19 from the ICD-10 classification of disease were included. The measurements comprised designated primary substance, existing multiple substance use disorder, substances involved and basic socio-demographics.

From 10,009 clients included in the study, 1,653 (16.5 per cent) were reported as having multiple substance use disorders. A great variety of substance combinations was identified and alcohol was found in the majority of them.

Treatment strategies targeting accurately substance-related disorders as a whole complex should be promoted. In particular the alcohol-related aspect of the disorder should not be neglected when the focus is on illegal drugs.

Multiple substance use was until recently not sufficiently documented in treatment monitoring systems. A recent version of the European treatment demand indicator (TDI) has introduced the notion of “polydrug use problem” as complementary information to the primary substance, which remains the key variable for reporting treatment demand. This study represents a first attempt to explore systematically this new data.