The Correlation between NPS and Polysubstance Use in High-Risk Population: a Five-year Longitudinal Study in Taiwan

The emergence of new synthetic substances (NPS) leads to rapid changes in substance prevalence. Here urine analysis and questionnaires were employed to construct a landscape of substance abuse. 3,064 urine samples were randomly selected from suspected substance abusers (N = 6,335) from 2014 to 2018 in Taiwan. Demographic information was self-reported. Principal component analysis (PCA) were used to explore the substance pattern. The positive detection of NPS reached 19.6%. The highest links of polysubstance use were the use of phenethylamines with the co-use of amphetamines (aOR = 4.33), benzodiazepines (aOR = 2.09), and synthetic cathinones (aOR = 5.01) and the use of synthetic cathinones with the co-use of ketamine (aOR = 6.72) and benzodiazepines (aOR = 2.62). No evidence indicating an increase in the use of NPS/other substances as a replacement for traditional substances. The presence of polysubstance patterns may be due to similarities in the effects of the various substances or users undergoing a transition in their substance abuse patterns.