Sleep disorders, particularly insomnia and daytime sleepiness, are increasingly prevalent globally, especially among young adults. Students, due to lifestyle changes (new residences, increased independence, stimulant use), are particularly vulnerable. Poor sleep hygiene and late sleep phases contribute to insufficient sleep. The COVID-19 pandemic further exacerbated these issues, leading to altered sleep patterns and increased insomnia. Sleep is crucial for mental and physical health; its disruption increases risks for chronic diseases and mental health issues, impacting daily functioning and QoL. While numerous studies exist, few examine diverse global regions with varying socioeconomic statuses. This study aimed to globally assess insomnia and daytime sleepiness prevalence among college students, evaluate their QoL, and identify risk factors including socioeconomic status and the COVID-19 pandemic's influence.

Existing literature extensively covers sleep disorders, but mostly focuses on specific times and locations, lacking a comprehensive global perspective encompassing diverse cultural and socioeconomic factors. Studies on students highlight the high prevalence of insomnia, varying by region and methodology. For example, studies showed insomnia prevalence ranging from 35.4% to 82.5% across different countries and student populations. Socioeconomic status is known to significantly impact health, but its effect on sleep remains inconsistently understood. There is evidence linking lower socioeconomic status to higher risk of sleep disorders, especially insomnia. The COVID-19 pandemic dramatically affected sleep patterns, with many studies reporting increases in insomnia and changes in diurnal rhythms among students. The impact of stimulants on sleep is complex, with studies indicating bidirectional relationships, with poor sleep increasing stimulant use and vice versa.

This cross-sectional study utilized a self-reported online survey distributed via Facebook from January 31, 2016, to April 30, 2021. The convenient sampling method recruited 20,139 students from 60 countries. The survey included sociodemographic data (age, sex, country, year of study, university type), stimulant use (alcohol, cannabinoids, psychostimulants, sedatives/hypnotics), and validated psychometric tools: the Athens Insomnia Scale (AIS), the Epworth Sleepiness Scale (ESS), and the Manchester Short Assessment of Quality of Life (MANSA). The AIS measures insomnia severity (cutoff ≥6), the ESS assesses daytime sleepiness (cutoff ≥11), and the MANSA evaluates QoL. Participants were categorized based on survey completion date (pre- and post-COVID-19 pandemic announcement) and country's GDP per capita and Human Development Index (HDI). Statistical analyses involved descriptive statistics, chi-square test, t-test, Kendall's tau correlation, and backward stepwise logistic and linear regression models to determine risk factors for insomnia, daytime sleepiness, and their impact on QoL.

The study found a high prevalence of insomnia (57.6%) and daytime sleepiness (27.0%) among the 20,139 college students. The mean AIS score was 8.26 ± 4.35, and the mean ESS score was 7.90 ± 4.23. Women (OR 1.25, p<0.001), low-income students, and non-medical students had a higher risk of insomnia. The risk of insomnia decreased with higher years of study and was lower among medical students (OR 0.90, p=0.004). A negative correlation was observed between GDP per capita and insomnia risk. The COVID-19 pandemic more than doubled the risk of insomnia (OR 2.17, p<0.001), while decreasing daytime sleepiness risk (OR 0.78, p<0.001). The mean MANSA score was 60.9 ± 11.46, indicating a moderately high level of subjective quality of life. QoL was significantly lower for students experiencing insomnia (B = −3.142, p < 0.001) or daytime sleepiness (B = −1.331, p < 0.001). Students from countries with very high HDI scored highest on MANSA (B = 2.001; p = 0.002). Hypnotic drug use negatively correlated with QoL. Psychostimulant use increased the risk of both insomnia and daytime sleepiness. Higher AIS and ESS scores were associated with lower MANSA scores (rAIS = −0.355, p < 0.001; rESS = −0.155, p < 0.001).

The high prevalence of insomnia and daytime sleepiness underscores the significant sleep health burden among college students globally. These findings align with previous research, albeit with variations based on factors such as geographic location, socioeconomic context and methodology. The study’s large sample size and global reach offer unique insights into the substantial impact of socioeconomic status on sleep. The observed negative correlation between GDP per capita and insomnia risk highlights the considerable influence of economic factors on sleep health, potentially mediated by access to healthcare, lifestyle choices, and living conditions. The COVID-19 pandemic's impact on sleep, demonstrated by an increase in insomnia risk, supports previous literature on the pandemic's effects on mental health. Differences in insomnia risk between medical and non-medical students might reflect differing academic demands and stressors. The negative correlation between sleep disorders and QoL aligns with findings showing significant impairments in mental and physical health among students with sleep problems. The study supports the need for interventions addressing sleep hygiene and appropriate management of stimulant use.

This large-scale global study confirms the high prevalence of insomnia and daytime sleepiness among college students, significantly impacting their quality of life. The study highlights the influence of socioeconomic factors and the COVID-19 pandemic on these conditions. Future research could explore specific cultural influences and longitudinal studies are needed to better understand the long-term implications of these sleep disorders. Public health campaigns promoting sleep hygiene and responsible stimulant use are warranted.

The study's reliance on self-reported online data limits the generalizability of the findings and introduces potential biases related to recall and social desirability. The inability to verify participant identity and the exclusion of data on chronic conditions and mental health diagnoses are limitations. The overrepresentation of female participants and a skewed distribution across socioeconomic strata also affect the interpretation and generalizability of the results. Future studies could utilize more objective assessments of sleep and incorporate additional data on relevant health conditions.