Prevalence and Severity of Insomnia among College Students: A Cross-Sectional Study

Introduction

Nighttime sleep duration is limited among university students and is closely linked with different adverse health effects such as decreased academic performance.¹ To cope with educational responsibilities and pressure, most pupils sacrifice their rest. Sleep quality consists of four key components: wakefulness at the beginning of the night, time taken to fall asleep, total sleep duration at night and the proportion of time actually spent sleeping. Sleep significantly reduces stress and fatigue, as high quality sleep enhances interpersonal interactions, improves responsiveness, and promotes overall well-being. Poor sleep is associated with fatigue, irritability, decreased ability to function during waking hours, as well as delay in reaction time, and greater tendency to drink alcohol and caffeine.^2,3

Adults in the age range of 18-60 years should ensure that he or she gets a minimum of seven hours of sleep per night for sound health and wellbeing. Failing to get a minimum of seven hours of sleep is a risk factor for high blood pressure, obesity, diabetes, heart disease, stroke, psychological disorders, and increased mortality. Sleep disturbances are broadly categorized under sleep disorders and include insomnia, which may be acute, episodic, or chronic. Not only it is presenting a sign of several different sleep disorders, for example insomnia, sleep apnoea or narcolepsy, but it is also directly related not only to a student's anxiety levels or level of depression, to name a few.^4-6

Globally, many adults are failing to get sufficient sleep, and this trend is also evident among college students.This group often experiences poor sleep quality, which has significant consequences. Sleep quality can be assessed using Pittsburgh Sleep Quality Index (PSQI), which is a self-administered tool that measures sleep quality in seven aspects - sleep duration, habitual sleep efficiency, perceived sleep quality, latency, sleep disturbances, use of sleep medications, and daytime dysfunction. These domains are grouped into three key factors: amount of sleep, regularity of sleep, and subjective sleep quality -including time taken to fall asleep, nighttime awakenings, use of sleep aids, and problems during the daytime.^7,8

However, insomnia remains underdiagnosed and undertreated, despite affecting a large portion of the population and posing serious health risks. The Insomnia Severity Index (ISI) is a psychometric tool used to determine the prevalence of insomnia in large population studies, and to track changes in insomnia symptoms in clinic populations. Research shows that over 60% of students are classified as poor sleepers according to the PSQI, and often exhibit delayed bedtimes and wakeup time on weekends. Many students use substances to induce sleep, reduce wakefulness or manage other sleeprelated issues, often without regard for whether these substances are legal, or require prescription.^9,10

Materials and Methods

To assess the sleep quality, the PSQI was employed, while ISI was used to measure the prevalence and severity of insomnia among college students. The PSQI evaluated aspects such as sleep quality, sleep duration, sleep disruption, and sleep latency, while the ISI assessed the severity of insomnia and its impact on daily functioning. Together, these tools enabled accurate and valid data collection on the pattern of insomnia within the target population.

Pittsburgh Sleep Quality Index (PSQI)

The PSQI assesses sleep quality using seven components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. Each component is scored on a scale of 0 to 3, with 0 indicating 'no difficulty' and 3 indicating 'severe difficulty'. The scores are summed to produce a global score ranging from 0 to 21, where higher scores indicate poorer sleep quality. A global score above 5 typically reflects significant sleep disturbances or poor sleep quality.

Insomnia Severity Index (ISI)

The ISI assesses the severity of insomnia symptoms over the past two weeks using seven items, each scored from 0 to 4. The total score ranges from 0 to 28, with categories as follows:

• 0-7: No clinically significant insomnia
• 8-14: Subthreshold insomnia
• 15-21: Moderate clinical insomnia
• 22-28: Severe clinical insomnia

Participants were recruited through a cross-sectional study design using random sampling of private colleges. Data were collected via an online questionnaire through institutional email lists and relevant social media accounts using Google forms. Ethical approval was obtained, and participants provided consent to be recorded during their participation.

To calculate the required sample size for this prevalence study, the formula n = Z² × p × (1 - p) / d² was used, where n represents the sample size, Z is the Z-score corresponding to the desired confidence level (e.g., 1.96 for 95% confidence), P is the estimated prevalence of insomnia based on prior studies or assumptions, and d is the margin of error (e.g., 0.05 for a 5% error margin).

The sample size was increased to 1225 based on previous prevalence studies and to account for probable dropouts. After excluding incomplete questionnaires, a final sample of 1025 was obtained and used for statistical analysis.

Descriptive statistics were used to present the demographic characteristics and the prevalence of insomnia, while inferential statistics tested relationships and predictors of severity of insomnia. The descriptive data were summarized in tables and graphs to provide a clear understanding of the findings.

Table 1 outlines the descriptive statistics such as range, mean, and standard deviation for the following quantitative parameters: age, Pittsburgh Sleep Quality Index (PSQI), and total score for insomnia.

Table 2 presents the descriptive statistics of qualitative parameters, such as gender and insomnia classification, along with their respective frequencies.

Table 3 shows no significant difference (P value >0.05) based on the Chi-square test comparing insomnia classification between males and females. Therefore, it can be concluded that there is no statistically significant association between gender and insomnia classification.

Discussion

It is important for college students to recognize that insomnia has become increasingly common, partly due to the demanding schedules imposed by the institutions along with resulting health implications. Based on the results obtained using the PSQI, our study found that college students are more prone to insomnia, consistent with findings of existing literature. While sleep duration has traditionally been used as the primary indicator of sleep health, recent research has shifted focus toward quality of sleep. Although sleep duration and quality are related, evidence suggests that sleep quality has a disproportionately greater impact on overall health.¹¹ 

Numerous cross-sectional surveys conducted among students from diverse socio-cultural settings have demonstrated that the PSQI effectively discriminates between good and poor sleepers. Research in this area consistently shows that approximately 30% to 70% of university students experience poor sleep quality and can be classified as poor sleepers.^10,12 A cross-sectional synthetic study revealed that the global prevalence of insomnia is approximately 30%, with rates of sleep disorders among university students ranging from 14.9% to 70.3%, depending on the region and study type.¹³ This led to variations in the reported rates of insomnia, based on differences in the evaluation methods, ranging from strict diagnostic criteria such as DSM-IV or the International Classification of Sleep Disorders to the use of quantitative scales, and the inclusion and exclusion of conditions without clearly defined criteria. Despite these variations, most studies consistently report low levels of sleep quality among university students in countries such as the USA, Jordan, China, Mongolia, Iran, Ethiopia, Qatar, Rwanda, and India.^14,15 

To the best of our knowledge, no research has specifically examined the prevalence of insomnia among college students in Bangalore city. Existing studies within the Indian context have primarily involved relatively small sizes or focused on different population segments. This study addresses that gap by targeting college students aged 18-25 years in Bangalore. The PSQI and the self-reported Insomnia Severity Index (ISI) were used to assess the prevalence and clinical severity of insomnia in a sample of 1,025 participants.

The PSQI is widely recognized for its validity and reliability in assessing sleep quality. It has demonstrated strong internal consistency, with a Cronbach's alpha coefficient of 0.83 across its seven components.¹⁶ The ISI is a reliable tool with strong internal consistency (Cronbach's alpha ~0.84) and excellent test-retest reliability (ICC ~0.84). It effectively measures insomnia severity and correlates well with other validated tools like the PSQI. Its proven validity ensures accurate assessment across diverse populations.¹⁷

These results highlight insomnia as a significant issue in this population and provide a foundation for future research focused on developing treatments for sleep disorders in young adults.

The current study highlights the distribution of insomnia severity within the studied population, revealing that the majority (54.3%) experienced no clinically significant insomnia, while 34.0% reported subthreshold insomnia, suggesting mild symptoms not necessitating clinical intervention. However, 9.9% of participants demonstrated moderate clinical insomnia, potentially requiring attention, and 1.9% suffered from severe insomnia, warranting urgent care. These findings align with previous studies that have reported a relatively low prevalence of severe insomnia compared to mild or moderate symptoms within the general population. Regarding gender differences, the study observed a marginal increase of 0.23% in insomnia prevalence among female subjects. However, statistical analysis confirmed that this variation was negligible and not statistically significant, consistent with past research suggesting only minor gender-based discrepancies in insomnia prevalence. These results reinforce the importance of targeted interventions for moderate to severe insomnia cases while considering demographic factors.

Using validated tools such as the PSQI and the ISI, this study confirms that students and individuals often experience poor sleep quality, a finding consistent with global cross-sectional research across diverse socio-cultural contexts. The observed increase in sleep disturbances and insomnia severity underscores the urgent need for tailored sleep health interventions in this population.

Prevention, proper diagnosis, and effective management of insomnia can significantly reduce the risk of anxiety and other mental health conditions, which are often linked to prolonged insomnia. The findings of this study strongly suggest that sleep health must remain a central component of student welfare and academic achievement agenda. Future research should focus on identifying crucial elements to guide the development of programs that help college students improve sleep quality and maintain their mental health.

Future research must therefore focus on developing and evaluating interventions aimed at alleviating severity of insomnia and improving the general well-being of individuals. Early management of insomnia may be particularly effective in the prevention of anxiety and other mental illnesses.9 As this study marks the significance of sleep health for supporting mental well-being of students, preventive measures and therapeutic interventions should be integrated into students' healthcare services. These results also provide a foundation for research into the effectiveness of behavioural and therapeutic approaches for treating insomnia, which is increasingly common among young adults in academic settings. 

Limitations

1. The findings may not be generalizable beyond the Bangalore region or the 18-25 age group.
2. Reliance on self-reported data may introduce biases and inaccuracies.
3. The cross-sectional nature of the study cannot establish causality or track changes over time.
4. The use of only two tools for sleep assessment may affect the precision of results.
5. External factors such as socio-economic diversity may not have been fully accounted for.

Conclusion

This research provides important evidence that a significant proportion of college students in Bangalore suffer from insomnia, with heavy academic workloads contributing to poor sleep quality and adverse health outcomes.

Conflict of Interest

Nil