Objectives: Sleep problems can have long-term negative consequences. This study explored the relationship of commonly used stimulant substances to poor sleep quality in young adults.
Methods: We surveyed 498 participants, aged 18 to 25, who reported recent alcohol or marijuana use. Stimulant substances measured included coffee, energy drinks, nonmedical prescription stimulants (NPS), cocaine, and nicotine. Sleep outcomes were measured using the Pittsburgh Sleep Quality Index (PSQI) and its components.
Results: Participants averaged 21.3 (±2.07) years of age, 47.8% male, 65.5% non-Latino white, 10.8% African-American, 12.3% Latino, and 11.5% other ethnic origins. In the past 30 days, 24.9% had used cigarettes, 48.1% energy drinks, 17.3% NPS, 79.3% coffee, and 7.9% cocaine. Mean PSQI global score was 6.21 (±3.66, median = 5). After adjusting for background characteristics, PSQI global scores were positively and significantly associated with number of cigarettes/day (b = 0.16, 95% confidence interval 0.07 to 0.25, P < 0.001) and days of NPS (b = 0.10, 95% confidence interval 0.01 to 0.18, P = 0.030).
Conclusions: NPS negatively affects sleep, but nicotine is particularly deleterious to sleep quality. Addressing smoking cessation to improve sleep may be a novel way to motivate young adult smokers to quit.
Trial registration: ClinicalTrials.gov NCT01473719.