Sense of coherence and substance use in Spanish adolescents. Does the effect of SOC depend on patterns of substance use in their peer group?

The aims of this work were to analyse the relationships between sense of coherence (SOC) and substance use among Spanish adolescents and to examine the potential moderator effect of the patterns of substance use in the peer group. Sample consisted of 5475 Spanish adolescents aged 15 to 18 from the 2010 edition of the Health Behaviour in School-aged Children (HBSC) study. Statistical analysis included cluster analysis to identify groups of adolescents according to their peer group's patterns of substance use and logistic regression with SOC and peers' pattern of consumption as predictors of current tobacco use, current alcohol use, life-time drunkenness and current drunkenness. The results showed that a strong SOC seemed to reduce the adolescents' likelihood of involving in tobacco use and drunkenness, but it was not associated with being a current drinker. In addition, the protective effect of SOC was moderated by peers' patterns of substance use. Specifically, SOC had a significant protective influence in adolescents whose peer group showed either a nonconsumption pattern or a pattern of frequent alcohol use and occasional drunkenness; but the protective effect of SOC disappeared if peers showed a pattern of consumption that included illegal drugs. In conclusion, SOC tends to act as a protective personal variable with respect to substance use during adolescence, but the influence exerted by the peer group seems to moderate the aforementioned protective effect of SOC.