European Journal of Cardiovascular Medicine

Adolescence is a developmental stage marked by profound biological, psychological, and social changes, many of which influence sleep patterns and behaviors. Sleep plays a critical role in physical growth, emotional regulation, cognitive functioning, and mental well-being. However, modern lifestyle factors such as academic pressure, increased screen exposure, and altered circadian rhythms have contributed to widespread sleep deprivation and disturbances among adolescents (1,2).

The National Sleep Foundation recommends that adolescents aged 13–18 years should receive 8–10 hours of sleep per night for optimal health (3). Yet, studies across various countries consistently report that a majority of adolescents sleep less than the recommended duration, with significant proportions also experiencing poor sleep quality (4,5). Reduced sleep duration and poor sleep quality during this crucial phase of neurodevelopment can negatively affect mood, concentration, academic performance, and social interactions (6,7).

Numerous studies have established associations between inadequate sleep and mental health issues, including anxiety, depression, emotional dysregulation, and behavioral problems (8,9). Poor sleep quality has also been implicated as a contributing factor to suicidal ideation and self-harm behaviors among adolescents (10). Mechanistically, sleep disturbances are thought to impair emotional regulation pathways and increase vulnerability to psychological stress (11).

The adolescent population is particularly vulnerable due to high exposure to digital devices, erratic sleep schedules, and social stressors, which can exacerbate both sleep and mental health challenges (12). In low- and middle-income countries, urbanization and academic competitiveness further compound the risk by disrupting traditional sleep patterns and increasing psychosocial burden (13).

Despite growing awareness, few population-level studies have systematically explored the relationship between sleep characteristics and mental health outcomes in adolescents, especially in rapidly urbanizing settings. This study aims to assess sleep duration and quality among urban adolescents and examine their associations with various dimensions of mental health using validated psychometric tools.

A total of 800 adolescents aged 13–18 years were recruited using a multistage random sampling technique. In the first stage, 12 secondary schools were randomly selected from a list of all registered urban schools. In the second stage, classes were selected from each school, and students were chosen proportionally based on the class strength. Adolescents who had been enrolled in the respective schools for at least six months and gave written informed assent along with parental consent were included.

Inclusion and Exclusion Criteria
Inclusion criteria were: adolescents aged between 13 and 18 years, attending regular school, and willing to participate. Exclusion criteria included students with known neurological disorders, chronic illnesses, or on medications that could influence sleep or psychological function.

Data Collection Tools
Sleep patterns were assessed using the Pittsburgh Sleep Quality Index (PSQI), a validated instrument measuring sleep quality over the past month. A global PSQI score >5 was considered indicative of poor sleep quality. Sleep duration was self-reported as average hours slept per night on school days.

Mental health status was assessed using the Strengths and Difficulties Questionnaire (SDQ), which evaluates emotional symptoms, conduct problems, hyperactivity/inattention, peer problems, and prosocial behavior. Each domain was scored and interpreted based on established cut-off values.

A structured questionnaire was used to collect data on sociodemographic variables (age, gender, parental education, household income), screen time (average daily hours), and academic stress (self-rated on a 5-point Likert scale).

Data Collection Procedure
Trained field investigators administered the questionnaires during school hours in a classroom setting. Prior to data collection, the purpose of the study was explained, and confidentiality was assured. Students were guided on how to complete the forms independently.

Statistical Analysis
All data were entered and analyzed using IBM SPSS Statistics version 26.0. Descriptive statistics such as mean, standard deviation, and proportions were calculated. Group comparisons were performed using independent t-tests and chi-square tests. Pearson correlation analysis was used to assess the relationship between sleep duration and SDQ subscale scores. Multiple linear regression was conducted to determine predictors of poor mental health outcomes, with p-values <0.05 considered statistically significant.

A total of 800 adolescents participated in the study. The mean age of the participants was 15.2 ± 1.4 years, with 412 (51.5%) males and 388 (48.5%) females. The mean self-reported sleep duration on school nights was 6.2 ± 1.3 hours, and 63.5% (n = 508) of participants had poor sleep quality based on PSQI global scores >5.

Sleep Characteristics and Demographics
As shown in Table 1, poor sleep quality was significantly more prevalent among females (68.3%) compared to males (59.0%) (p = 0.011). Sleep duration was significantly shorter in older adolescents (16–18 years: 5.9 ± 1.1 hrs) compared to younger ones (13–15 years: 6.5 ± 1.4 hrs; p < 0.001).

Table 1. Distribution of Sleep Quality and Duration by Age and Gender (n = 800)

*Statistically significant at p < 0.05

Correlation between Sleep and Mental Health
Participants with poor sleep quality had significantly higher total SDQ scores (Mean = 19.8 ± 5.7) compared to those with good sleep quality (Mean = 14.3 ± 4.1, p < 0.001). A moderate negative correlation was observed between sleep duration and emotional symptom scores (r = –0.42, p < 0.001) (Table 2).

Table 2. Comparison of SDQ Scores by Sleep Quality (n = 800)

*Statistically significant at p < 0.05

Predictors of Poor Mental Health
Multiple linear regression analysis identified poor sleep quality (β = 0.39, p < 0.001), reduced sleep duration (β = –0.27, p = 0.002), screen time >3 hours/day (β = 0.21, p = 0.005), and high academic stress (β = 0.34, p < 0.001) as significant predictors of higher SDQ scores. The final model explained 31.2% of the variance in mental health outcomes (adjusted R² = 0.312, F = 34.6, p < 0.001).

This study highlights a concerning prevalence of poor sleep quality (63.5%) and inadequate sleep duration (mean 6.2 ± 1.3 hours) among adolescents, supporting global evidence of worsening sleep health in this age group. Notably, adolescents with poor sleep quality exhibited significantly higher emotional and behavioral difficulties, as reflected by elevated Strengths and Difficulties Questionnaire (SDQ) scores.

Our findings are consistent with earlier studies that have reported widespread sleep disturbances among adolescents, often attributed to academic demands, digital media exposure, and social stressors (1,2). The average sleep duration in our study falls below the National Sleep Foundation’s recommendation of 8–10 hours per night for this age group (3). Similar trends have been reported in both high-income and developing countries, indicating a global shift in adolescent sleep patterns (4,5).

Gender differences in sleep quality were observed, with females reporting higher rates of poor sleep. This aligns with prior research suggesting that adolescent girls are more susceptible to sleep disturbances due to hormonal changes and heightened emotional reactivity (6,7). Older adolescents (16–18 years) also reported shorter sleep durations, which may reflect increasing academic pressures and social commitments during late adolescence (8).

The association between sleep and mental health observed in our study is well-supported by literature. Poor sleep quality and short duration have been linked to a range of emotional and behavioral disorders, including anxiety, depression, hyperactivity, and impaired social relationships (9–11). Our study demonstrated a moderate negative correlation (r = –0.42) between sleep duration and emotional symptoms, reinforcing findings from longitudinal and cross-sectional studies (12).

The multivariate analysis further revealed that sleep disturbances, screen time exceeding three hours, and academic stress significantly predicted higher SDQ scores. This emphasizes the complex interplay between digital habits, academic burden, and mental health, which has been well-documented in adolescent populations (13,14). Excessive screen exposure, particularly before bedtime, has been shown to delay sleep onset, reduce REM sleep, and disrupt circadian rhythms, contributing to both sleep and mood disturbances (15).

Strengths of the study include the use of validated tools (PSQI and SDQ), a large sample size, and a population-based sampling strategy, which enhance the generalizability of the findings. However, limitations include the cross-sectional design, which limits causal inference, and reliance on self-reported sleep data, which may be subject to recall bias.

Despite these limitations, the findings underscore the urgent need for integrated public health interventions focused on improving adolescent sleep hygiene. Educational programs, family engagement, and school-based screening for sleep and mental health issues may help mitigate long-term psychosocial risks.

This study reveals a high prevalence of poor sleep quality and insufficient sleep duration among urban adolescents, both of which are significantly associated with emotional and behavioral difficulties. Key predictors such as screen time and academic stress further highlight the multifactorial nature of sleep-related mental health issues. These findings underscore the need for school-based sleep health education and broader psychosocial interventions to enhance adolescent well-being.

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