Waterpipe smoking patterns and symptoms of nicotine dependence: The Waterpipe Dependence in Lebanese Youth Study: The Waterpipe Dependence in Lebanese Youth Study

Introduction Waterpipe typically is smoked intermittently over long smoking sessions. Waterpipe is addictive and its users show symptoms of nicotine dependence (ND). This study examined the risk of developing ND symptoms across waterpipe use patterns among Lebanese youth. Methods Waterpipe use patterns (length of smoking session, smoking a whole waterpipe without sharing, past-30 day use frequency, number of waterpipes smoked) were assessed. Symptoms of ND were assessed using the 10-item Hooked on Nicotine Checklist (HONC; endorsement of ≥ 1 symptom) and the 6 criteria of the International Classification of Diseases-10th revision (ICD-10 ND; presence of ≥ 3 criteria during 12 months). Results Both the proportion of participants endorsing ND symptoms and the average number of endorsed ND symptoms increased with increasing waterpipe use frequency, number of waterpipes smoked, and length of smoking session. The risk of endorsing ≥ 1 HONC symptom increased with increasing number of waterpipes smoked in the past 30-days (≥ 10 vs. < 4 waterpipes; Hazard ratio (HR) = 2.05, 95% CI: 1.52–2.58, p = 0.007), and session length (> 60 min vs. < 30 min; HR = 2.87, 95% CI: 2.83–2.91, p = 0.001). The risk of attaining ICD-10 ND increased with increasing number of waterpipes used in the past 30-days (≥ 10 vs. < 4 waterpipes; HR = 2.56, 95% CI: 1.89–3.22, p = 0.006), and smoking every day/almost every day vs. less than once weekly (HR = 2.86, 95% CI: 2.12–3.60, p = 0.007). Conclusions Increasing use frequency, number of waterpipes smoked, and longer smoking sessions were associated with higher risk of ND. The length of smoking session emerged as a novel indicator of ND among waterpipe smokers.