The declining trend in Swedish youth drinking: collectivity or polarization?

Aims Alcohol consumption among youth in Sweden has declined markedly during the last decade. This study aims to tackle the following research questions: (i) how is the decrease in drinking distributed across consumption categories; and (ii) is the pattern of change in consumption consistent with Skog's theory of the collectivity of drinking behaviour? Design, Setting, Participants and Measurements We analysed data from the nationally representative annual school survey of alcohol and drug habits among Swedish 9th-grade students (aged 15-16 years) covering the period 2000-12 (n approximate to 5000/year). Respondents were divided into seven drinking groups based on their relative ranking on consumption, which was measured by beverage-specific quantity and frequency items summarized into a measure of overall drinking in litres of 100% alcohol per year. In addition, the mean number of heavy episodic drinking occasions (HED) was computed for each drinking group. Findings The decline in consumption among Swedish youth was mirrored in all seven drinking groups, although the relative decrease was smaller for heavy drinkers (top 5%) than for light drinkers (below the median). Among the top 5%, the average annual decrease was 2% (P = 0.027), while the corresponding figure for light drinkers was 28.9% (P < 0.001). The reverse pattern was true when looking at the absolute decrease. The decrease among the top 5% accounted for 26.1% of the decrease in mean consumption during the study period, whereas the light drinkers accounted for 2.9%. There was a marked relation between overall consumption, on one hand, and mean consumption and HED, on the other hand, in each of the seven drinking groups. Conclusion The marked decrease in youth drinking in Sweden that occurred during the period 2000-12 was manifest at all consumption levels. The findings are consistent with Skog's theory of the collectivity of drinking behaviour.