Psychological consequences of insufficient sleep in medical students

Abstract

Background

Insufficient sleep is a common public health issue among students, and it is necessary to investigate this phenomenon and its consequences. Therefore, the present study aimed to examine the psychological consequences (i.e., somatization, depression, anxiety, and hostility) of insufficient sleep in medical students.

Methods

The sample in this cross-sectional study consisted of 448 college students (with a mean age of 23.47 years; 56.7% female) from Kermanshah University of Medical Sciences at Iran. Symptom Checklist-90-Revised Form (SCL-90-R) and several self-report questionnaires (physical activity, bedtime, sleep duration, and daily nap) were used to collect data, and the results were analyzed using ANOVA and ANCOVA.

Results

The results showed statistically significant differences in the mean scores of anxiety (F = 10.84, η² = 0.070), depression (F = 7.52, η² = 0.050), somatization (F = 13.07, η² = 0.082), and hostility (F = 5.28, η² = 0.035) among groups based on sleep duration. These differences remained significant even after controlling for the effects of physical activity, bedtime and daytime napping (all p < 0.01).

Conclusion

According to the results, insufficient sleep and short sleep duration are significantly associated with elevated anxiety, depression, somatization, and hostility. A key limitation is the reliance on a single self-report item for assessing sleep duration, which is subject to recall bias. Future longitudinal studies with objective sleep measures be conducted to explore the causal links between sleep duration and mental health.

Introduction

Sleep plays an important role in mental health [1]. Psychological problems such as anxiety, depression, and stress are influenced by sleep-related behaviors and disturbances [2, 3]. One aspect of the sleep pattern is sleep duration, which was examined in the present study. Results of some studies showed that sleep duration negatively affects mood and it is involved in depression [4, 5]. It is also claimed that some sleep disorders (e.g., insomnia) are global health problems among college students and they are associated with various psychiatric issues, such as anxiety [6]. On the one hand, healthy and sufficient sleep is an important factor in the physical and mental health of the community, particularly college students. On the other hand, research showed that between 12 and 50% of college students meet criteria for one or more psychiatric disorders and they are a high-risk group [7, 8]. Therefore, more effort should be made in understanding and recognizing sleep problems and psychological outcomes in the targeted population.

Specifically, the prevalence of sleep disorders among medical students is higher than that of non-medical students due to various reasons, including the number of classes and lifestyle factors [9], and a high percentage of them have a sleep duration of less than 7 h [10]. Additionally, the prevalence of anxiety among students exceeds 23% [11], while the prevalence of depression in medical students has been reported to be over 27% [12]. A study’s results showed that more than 50% of medical students were in a critical state regarding somatization [13]. Extensive study is needed to investigate the causes of these problems _especially insufficient sleep_ in medical students.

Insufficient sleep differs from insomnia and is often mistakenly diagnosed as such. This study focuses on insufficient sleep. Often, there has been discussion about insufficient sleep, and it has even been claimed to be a public health concern [14]. Insufficient sleep syndrome is defined as a limited sleep pattern lasting at least three months on most days of the week, accompanied by complaints of daytime sleepiness. Furthermore, complaints of sleepiness have been shown to resolve following an increase in total sleep time [15]. A review study indicated that the insufficient sleep is related to a wide range of issues include inattention, reduced executive functioning, and poor academic performance to increased risk of obesity, cardiometabolic dysfunction, mood disorders, increased suicidal thoughts, a higher risk of risky behaviors, and heightened rates of traffic accidents, occupational injuries, and sports-related injuries [16]. Moreover, this sleep issue has adverse effects on memory, attention, alertness, judgment, decision-making, and overall cognitive abilities of the brain [17]. Insufficient sleep is highly prevalent in today’s society and represents a public health problem worldwide [18]. Medical students are among the groups vulnerable to insufficient sleep, experiencing many adverse effects [9]. Therefore, due to its importance, it was examined in the present study. In the absence of a concise diagnostic tool suitable for our study design, short sleep duration was employed as a key proxy measure for investigating the broader construct of insufficient sleep.

The results of a meta-analysis [19] revealed that short sleep duration is an independent predictor of developing mental disorders, particularly anxiety and depression. The findings of another meta-analysis [20] indicated that both short and long sleep durations are significantly associated with an increased risk of depression in adults. Results from a longitudinal study [21] showed that individuals with short sleep duration (≤ 4–5 h per night) had a higher risk of developing depression compared to those who slept 7 h per night. However, we still require a more precise and comprehensive understanding of the relationship between short sleep duration and mental health among Iranian university students. Especially medical students, who face academic stress and burnout [22], intense academic pressure, long clinical hours, and emotional distress [23] from patient care.

Additionally, evidence shows that physical activity plays a beneficial role in mental health [24, 25], and can improve sleep quality [26]. A regular exercise program can enhance the quality of life in medical students [27]. However, the question remains whether physical activity can compensate for the adverse effects of reduced sleep duration on mental health. This is one of the questions that will be examined in the present study.

We investigated insufficient sleep that is a significant public health issue among students, especially medical students [9], and can have considerable impacts on their psychological aspects and daily functioning [17]. Given the academic pressures and stressful environment faced by this group, sleep deprivation may lead to increased anxiety, depression, impaired concentration, and reduced quality of life [3, 28]. Therefore, investigating the psychological consequences of insufficient sleep in this vulnerable population is crucial. It can not only enhance our understanding of the problem but also inform the development of targeted interventions to improve mental health and sleep quality among medical students. However, there remains a gap in studies that specifically and comprehensively assess the psychological profile associated with varying sleep durations in this group while accounting for key behavioral factors. Accordingly, this study aimed to investigate the psychological consequences of short sleep duration in medical students. Specifically, it tested whether the means of anxiety, depression, somatization, and hostility differ significantly among groups with insufficient, sufficient, and long sleep durations. Furthermore, the potential confounding effects of physical activity, daily naps, and sleep schedule on these comparisons were controlled for in the analysis.

Methods

Design and context

This cross-sectional study was conducted among university students at Kermanshah University of Medical Sciences (KUMS), a public, degree-granting institution located in western Iran. Situated in Kermanshah province, KUMS admits students from diverse cities across Iran as well as from other countries, offering a wide range of academic programs in the medical and health sciences (including Medicine, Dentistry, Pharmacy, Nursing, Midwifery, Public Health, and Paramedical Sciences). The present research focused exclusively on Iranian-nationality students from these various programs and was carried out in the year 2024.

Participants and procedure

Initially, students were informed about the study and invited to participate voluntarily. After obtaining approval from the university’s research vice-chancellor and securing all necessary permits, a total of 460 paper-based questionnaires were distributed to students who expressed interest in participating (convenience/voluntary response sampling method). The research objectives were clearly explained to the selected individuals, and a trained staff member was present to provide any needed clarifications during questionnaire completion. Participants completed the questionnaires individually under the researcher’s supervision. All participants cooperated willingly and were assured that their data would remain anonymous and confidential.

The target sample size was determined based on the common rule of thumb in survey research, which recommends 10–15 participants per variable for adequate statistical power. Considering the number of variables included in our analysis, a minimum sample size of approximately 460 participants was targeted. The study sample included students aged 18 to 45 years, enrolled in various academic programs and disciplines across faculties affiliated with the university. Students currently using sleep medications or those of non-Iranian nationality were excluded from the study. Individuals were excluded if they reported a diagnosed primary sleep disorder (e.g., insomnia disorder, sleep apnea), a current or past major psychiatric illness, engagement in regular night shift work, or high daily caffeine intake (defined as consumption exceeding 400 mg per day, approximately equivalent to 4 cups of coffee). After excluding incomplete questionnaires, defined as those missing more than 5% of responses, 448 completed questionnaires were deemed eligible and included in the final analysis.

Ethical considerations

Ethical considerations were carefully observed in this study. The study objectives were clearly and understandably explained to the participants. Participation was entirely voluntary, with no coercion of any kind. Participants were assured that all results from surveys and tests would be kept strictly confidential, with confidentiality maintained as a fundamental principle. Identifiable personal information was not recorded; instead, codes were used solely to identify the data. Participants had the right to withdraw from the study at any stage, including during data collection. Informed consent was obtained from all participants, who signed the relevant consent forms. This study was received ethical approval from the Ethics Committee of Kermanshah University of Medical Sciences (IR.KUMS.MED.REC.1403.013).

Instruments

Demographic Information Questionnaire: A demographic questionnaire was used to assess characteristics such as age, gender, marital status, substance use, and medical history. Information regarding the use of stimulant/sedative medications and a history of psychiatric disorders was collected via a self-report demographic questionnaire. Participants’ responses to these items were used to apply the study's exclusion criteria.

Symptom Checklist-90-Revised (SCL-90-R): This questionnaire is designed to assess a wide range of psychological problems and psychiatric symptoms with a good psychometrics [29]. It consists of 90 items with a five-point response scale (0 = none, 1 = a little, 2 = moderate, 3 = a lot, 4 = very much). Each subscale score is calculated as the mean of its item scores, providing an index of the severity of psychological symptoms. The SCL-90-R has nine subscales: Somatization (12 items), Obsessive–Compulsive (9 items), Interpersonal Sensitivity (9 items), Depression (13 items), Anxiety (10 items), Hostility (6 items), Phobic Anxiety (7 items), Paranoid Proneness (6 items), and Psychoticism (4 items). It also contains seven additional items. The SCL-90-R has shown acceptable reliability and validity in Iranian context [30]. In the present study, the Persian version only for somatization (α = 0.91), depression (α = 0.92), anxiety (α = 0.92), and hostility (α = 0.86) items were utilized.

Physical activity: To measure physical activity levels, a two-item researcher-developed questionnaire was used. The first item asked participants to rate, “How would you describe the amount of physical activity you engage in?” Participants selected one option from the following: i- I am hardly active (score 1), ii- I am slightly active (score 2), iii- I am moderately active (score 3), iv- I am very active (score 4), and v- I am extremely active (score 5). The second item asked, “Do you engage in daily exercise or physical activities?” For this question, participants chose from: never (score 1), very rarely (score 2), rarely (score 3), sometimes (score 4), often (score 5), and very often (score 6). The total score, ranging from 2 to 11, represents the individual's overall level of physical activity, with higher scores indicating greater activity. Based on these scores, participants were categorized into four groups: no activity, low activity, moderate activity, and high activity.

Sleep duration: To measure sleep duration, the Pittsburgh Sleep Quality Index was used. This is a self-report instrument, and its psychometric properties have been validated within the Iranian culture [31]. Participants are asked, “During the past month, how many hours of actual sleep did you get each night?” and they provide a numerical response. In the present study, based on the recorded sleep duration responses, individuals were categorized into four groups. Sleep duration was assessed using the corresponding single-item question from the Pittsburgh Sleep Quality Index (PSQI). Participants' responses were categorized into four groups (1–5, 5–7, 7–9, and 9–12 h per night) based on the data distribution and to align with operational definitions frequently used in sleep research [32–34], where durations outside the 7–9-h range are often considered non-normative.

Daily nap: To assess daytime napping, two researcher-developed questions were asked of the participants. The first question was: “During the past month, have you taken naps during the day?” Respondents were asked to choose one of three options: i– no, ii– some days, iii– every day. The scoring method for the first item was as follows: a score of 1 was assigned to the option “No”, a score of 2 to the option “Some days”, and a score of 3 to the option “Every day”. The second question was: “If you have taken daytime naps, how long were they?” The response options for this question included five choices: i– I have not taken naps, ii– about 15 min, iii– between 15 and 30 min, iv– between 30 min and 1 h, and v– more than one hour. For scoring this item, option 1 was scored as 0, option 2 as 1, option 3 as 2, option 4 as 3, and option 5 as 4.

Bedtime: One of the questions in the PSQI [35] concerns bedtime, asking: “During the past month, what time have you usually gone to bed at night?” Based on the responses, participants were divided into four bedtime categories: before 9:00 PM, 9:00 PM–11:00 PM, 11:00 PM–2:00 AM, and after 2:00 AM. This categorization was adapted to align with the conceptual framework of circadian rhythm sleep–wake disorders in the International Classification of Sleep Disorders, 2nd Edition (ICSD-2) [36]. While the ICSD-2 does not prescribe these exact time boundaries, it emphasizes the clinical significance of habitual sleep schedules that are significantly advanced or delayed relative to conventional or socially acceptable times. Our categories were designed to operationalize this spectrum, distinguishing between early, conventional, late, and very late sleep schedules for analysis.

Data analysis

Descriptive statistics such as mean and standard deviation were used to characterize the sample based on the variables studied. After checking the statistical assumptions for the analysis of variance, one-way analysis of variance (ANOVA) was employed to compare anxiety, depression, somatization, and hostility across groups. To account for the effects of physical activity, sleep duration, and daytime napping when comparing group means, one-way analysis of covariance (ANCOVA) was used. The primary independent variable for the analysis of variance (ANOVA) and analysis of covariance (ANCOVA) was sleep duration, categorized into four groups: 1–5 h, 5–7 h, 7–9 h, and 9–12 h per night. Separate one-way ANOVAs were conducted to compare the mean scores of anxiety, depression, somatization, and hostility across these four sleep duration groups. For head-to-head comparisons of each class with other categories, we used the Bonferroni post hoc test.

To control for potential confounders, a series of one-way ANCOVAs were subsequently performed. In these analyses, the dependent variables (psychological scores) and the independent grouping variable (sleep duration categories) remained the same. The following variables were included as covariates: self-reported physical activity level, frequency of daily naps, and bedtime category (as defined earlier). This approach allowed us to examine the association between sleep duration and psychological outcomes while statistically adjusting for the influence of these key behavioral factors. All statistical analyses were performed using SPSS version 27 (IBM Corp., Armonk, NY, USA). All tests were two-tailed, and statistical significance was defined as a p-value less than 0.05.

Results

This study included a total of 448 participants, with 254 (56.7%) women and 194 (43.3%) men. The participants' ages ranged from 18 to 45 years, with a mean age of 23.5 ± 3.8. For a detailed breakdown of demographic variables, see Table 1. As shown in this Table, 14.8% of individuals have a sleep duration between 1 and 5 h, 52.7% have a sleep duration between 5 and 7 h, 29.6% have a sleep duration between 7 and 9 h, and 2.9% of individuals have a sleep duration of more than 9 h. Group one (with a sleep duration between 1 and 5 h) was considered the group with insufficient sleep, which includes 66 people (56.7% women), and 78.8% of them are in the age group of 18 to 35 years.

Table 1.

The sociodemographic characteristics of the sample

Variables	N (%)	Sleep duration (hours)
		1–5	5–7	7–9	9–12
Sex
Female	254 (56.7)	43.9	58.3	58.3	69.2
Male	194 (43.3)	56.1	41.7	41.7	30.8
Education
MD	274 (61.2)	77.3	62.6	50.8	61.5
BA	166 (37.1)	19.7	36.2	47.7	30.8
MA	8 (1.8)	3	1.3	1.5	7.7
Marriage
Single	404 (90.2)	89.4	89.8	90.2	100
Married	44 (9.8)	10.6	10.2	9.8	0
Age
18–35	353 (78.8)	78.8	76.2	81.8	92.3
25–35	89 (19.9)	21.2	21.7	17.4	7.7
35–45	6 (1.3)	0	2.1	0.8	0
Sum	448 (100)	14.8	52.7	29.6	2.9

Values are presented as %. Percentages are column-based, indicating the proportion of participants with a given characteristic within each sleep duration category

Table 2 and Fig. 1 show the mean and standard deviation of psychological variables by group (based on sleep duration). Visually, the results showed that there is a U-shaped relationship between sleep duration and anxiety level, such that short sleep (1–5 h) and long sleep (9–12 h) were associated with higher anxiety levels (11.89 and 17.46, respectively), while optimal sleep (7–9 h) had the lowest mean anxiety (7.29). ANOVA and post hoc test confirmed a significant difference between groups (F = 10.84, p < 0.001) with a small to moderate effect size (η2 = 0.07). The analysis results also showed a significant relationship between sleep duration and depression level (F = 7.53, p < 0.001) with a small effect size (η2 = 0.05). The mean depression scores in the short sleep group (1–5 h: M = 17.35) and the long sleep group (9–12 h: M = 22.38) were significantly higher than in the optimal sleep group (7–9 h: M = 12.21). Furthermore, the results indicate a significant relationship between sleep duration and somatization symptoms (F = 13.07, p < 0.001) with a medium effect size (η² = 0.082). The mean somatization scores in the short sleep group (1–5 h: M = 13.30) and the long sleep group (9–12 h: M = 20.00) were significantly higher than in the optimal sleep group (7–9 h: M = 7.72). The moderate sleep group (5–7 h) had a mean of 9.02, placing it at an intermediate level. These findings demonstrate a U-shaped observed (no statistical) pattern where both short and long sleep are associated with increased somatic symptoms, while 7–9 h of sleep is related to the lowest levels of these symptoms. The analysis results also reveal a significant difference in hostility levels between groups, albeit with a small effect size. Specifically, the insufficient sleep group exhibited higher average hostility compared to the optimal sleep group.

Table 2.

Mean and standard deviation of the variables according to sleep duration

Variable	Sleep duration				F	p	Eta2	Multiple comparisons*
	1–5 h	5–7 h	7–9 h	9–12 h
Anxiety	11.89 ± 8.30	8.92 ± 7.45	7.29 ± 6.89	17.46 ± 11.40	10.84	< 0.001	0.07	1 > 2, 1 > 3, 2 < 4, 3 < 4
Depression	17.35 ± 11.04	13.42 ± 9.28	12.21 ± 9.42	22.38 ± 13.99	7.52	< 0.001	0.05	1 > 2, 1 > 3, 2 < 4, 3 < 4
Somatization	13.30 ± 10.34	9.02 ± 8.50	7.72 ± 7.21	20 ± 11.16	13.07	< 0.001	0.08	1 > 2, 1 > 3, 2 < 4, 3 < 4
Hostility	7.01 ± 5.16	5.30 ± 4.52	4.88 ± 4.63	8.76 ± 5.83	5.28	0.001	0.035	1 > 3, 3 < 4

^*Post-hoc pairwise comparisons were performed using the Bonferroni correction to adjust for multiple comparisons

Fig. 1.

Mean variables in the study groups

To account for the effects of physical activity, bedtime and daily napping when comparing group means, a ANCOVA was conducted (see Table 3). The ANCOVA results, controlling for physical activity, bedtime, and daily napping, revealed significant differences between groups across psychological variables. For all variables—anxiety, depression, somatization, and hostility—the F values and significance levels (p < 0.01) confirmed a significant group effect after adjusting for covariates. Somatization exhibited the largest effect size (η² = 0.076 to 0.080), followed by anxiety (η² = 0.061 to 0.070), indicating these variables showed the greatest differences between groups. Depression and hostility, although statistically significant, demonstrated smaller effect sizes (η² = 0.032 to 0.049). Notably, the pattern of results was consistent across all three covariates (physical activity, bedtime and daily napping), underscoring the stability of these findings. These outcomes highlight that, even after controlling for lifestyle-related factors, significant psychological differences persist between groups.

Table 3.

Group mean comparisons after controlling for physical activity, bedtime and daily napping

Variable	Covariate: physical activity			Covariate: bedtime			Covariate: daily nap
	F	p	Eta2	F	p	Eta2	F	p	Eta2
Anxiety	9.48	< 0.001	0.061	11.007	< 0.001	0.070	10.48	< 0.001	0.067
Depression	6.31	< 0.001	0.041	7.40	< 0.001	0.049	7.24	< 0.001	0.047
Somatization	12.06	< 0.001	0.076	12.58	< 0.001	0.080	12.74	< 0.001	0.080
Hostility	5.01	0.002	0.033	4.80	0.003	0.032	5.05	0.002	0.034

Discussion

In the present study, nighttime sleep duration was considered as the independent variable. Our results showed a observed U-shaped relationship between sleep duration and anxiety, depression, somatization, and hostility. Specifically, the mean symptom levels were higher in individuals who slept less than 5 h per night and those who slept more than 9 h per night compared to others. Our findings indicated that the optimal sleep duration for nighttime sleep is between 7 and 9 h, with 29.6% of students falling into this group. However, the majority, 67.5%, suffer from insufficient sleep, defined as sleeping less than 7 h.

Various studies have examined sleep duration among students. One study reported that 34.3% of medical students sleep less than 7 h on typical weeknights [10]. Another study found that 39.2% of students sleep 6 to 7 h daily [37]. Additionally, a study reported the average sleep duration of medical students as 7.5 ± 2.1 h [38]. Causes of reduced sleep duration include excessive use of the internet and social media [39], academic pressure and stress [40], unhealthy lifestyle [41], heavy workload and patient contact [42], and the educational environment [43].

Research on the consequences of insufficient sleep is limited, A study found that sleeping less than 7 h per night is associated with depression among medical students [44]. Additionally, research has indicated that reduced sleep increases the risk of depression [45]. Therefore, the results of the present study are consistent with previous research.

Our findings showed the increased anxiety levels in students with short sleep duration. One potential explanation for this link could involve the effect of sleep on amygdala reactivity—a brain region central to processing negative emotions [46]. It is hypothesized that insufficient sleep might impair the brain's ability to modulate emotional responses, potentially reducing the amygdala's regulatory capacity and increasing vulnerability to stress and anxiety. However, these neurobiological pathways remain speculative within the context of our correlational study and require direct investigation in future research.

Moreover, our study showed that insufficient sleep is related to depressive symptoms. The results of a study [47] showed that sleep problems may lead to depression by increasing fatigue and reducing motivation and feelings of efficacy. Furthermore, reduced sleep disrupts neurotransmitters such as serotonin, dopamine, and norepinephrine, which play crucial roles in mood regulation [48]. These neurochemical changes can create a foundation for the development or exacerbation of depression.

Our results also indicated that individuals with shorter sleep durations exhibited higher levels of somatization, consistent with prior studies [49, 50]. Sleep deprivation impairs immune system function and increases chronic inflammation [51, 52], which may lead to various physical symptoms including chronic pain, fatigue, headaches, and other discomforts. Additionally, insufficient sleep negatively affects the central nervous system and can heighten sensitivity to pain and physical discomfort, manifesting as somatic complaints [53].

Furthermore, the present study found that insufficient sleep associated with increasing hostility and aggressive behaviors. This can be explained by reduced functioning of the prefrontal cortex, as sleep deprivation decreases the activity and capacity of this brain region [54], which is responsible for impulse control, emotion regulation, and logical decision-making. Impaired prefrontal cortex function increases impulsive and aggressive behaviors. Insufficient sleep reduces one’s ability to manage negative emotions [55] such as anger and dissatisfaction, thereby increasing the likelihood of hostile reactions.

Our study also revealed that, after controlling for lifestyle factors—including physical activity, bedtime, and daytime napping—significant psychological differences remained between the groups. In other words, physical activity and napping cannot offset the negative effects of insufficient sleep. This finding underscores the important principle that insufficient sleep has a detrimental impact on mental health, and other healthy lifestyle behaviors (such as regular exercise) cannot fully compensate for the adverse consequences of sleep deprivation. The results also indicate that daytime napping does not replace or compensate for nighttime sleep. Given that previous research has shown nighttime sleep plays a fundamental role in brain restoration, hormone regulation, emotional processing, and memory consolidation [56–59], no other behavior can fully replicate these complex restorative processes. Therefore, based on these findings, while exercise and physical activity are beneficial for general health and mood improvement, they cannot completely mitigate the harmful effects of insufficient sleep; rather, their positive effects complement adequate sleep.

The findings related to the long sleep duration group (more than 9 h) in this study, while statistically significant, should be interpreted with caution. The small size of this group (13 people) means that the reported averages lack sufficient statistical stability and may potentially be influenced by the extreme characteristics of a few specific participants. Therefore, these figures should not be considered as a reliable parametric estimate of the long-sleep population. However, the general trend of these findings, indicating higher levels of psychological distress in this group, is consistent with epidemiological evidence linking long sleep duration to adverse mental health outcomes.

Limitations

This study was cross-sectional, so causal inferences regarding the effects of insufficient sleep cannot be made. Data were collected at a single point in time, and students’ sleep patterns may vary throughout the semester (e.g., near exams). Thus, sleep should be assessed over longer periods and at different times. Another limitation was that participants were volunteers, which may have introduced selection bias. Additionally, the sample consisted only of Iranian students, so caution should be exercised in generalizing the results; these variables should be examined within other societies and cultural contexts. Finally, variables such as sleep duration, napping, and physical activity were measured using single-items (e.g., some PSQI items) and short self-report instruments that are prone to recall bias (the status during past month) and lack objective validation. Future research would benefit from employing objective measures (e.g., actigraphy and accelerometer) and validated instruments to increase the robustness and precision of the findings.

Conclusion

Based on the results of this study, it can be concluded that nighttime sleep duration has an observed U-shaped relationship with anxiety, depression, somatization, and hostility. Individuals with optimal sleep duration—between 7 and 9 h per night—exhibited lower average levels of anxiety, depression, somatic complaints, and hostility. The findings also showed that physical activity, bedtime, and daytime napping do not mitigate the harmful effects of insufficient sleep. Therefore, it is recommended that university policymakers and health planners develop strategies to reduce insufficient sleep among students. Sleep health awareness programs for university students, particularly in demanding fields like medicine, may be considered as a potential strategy. These programs could focus on providing education about sleep hygiene and the potential mental health impacts of short sleep duration.

Abbreviations

PSS

Perceived stress scale

PSQI

Pittsburgh sleep quality index

RMSEA

Root mean square error of approximation

SD

Standard deviation

Author contributions

A.Z. contributed equally to conceptualization and data curation, investigation, methodology, project administration, validation, and visualization. A.Z. also led to formal analysis and software development, funding acquisition, and the writing of the original draft. B.R. contributed equally to conceptualization, data curation, investigation, methodology, project administration, validation, visualization, reviewing, and editing. K.S. contributed equally to investigation, resources, visualization, validation, reviewing, and editing. A.F. equally to investigation, resources, visualization, validation, reviewing, and editing. S.K. contributed equally to investigation, methodology, resources, formal analysis, visualization, validation, reviewing, and editing. S.K. also led to reviewing and editing. All authors read and approved the final manuscript.

Funding

This project was financially supported by the Kermanshah University of Medical Sciences (Code: KUMS- 4030079).

Data availability

Data will be made available upon request from the corresponding author.

Declarations

Ethics approval and consent to participate

The study protocol is consistent with the Helsinki Declaration (https://www.wma.net/policies-post/wma-declaration-of-helsinki/). This research was approved by the ethics committee of the Kermanshah University of Medical Sciences (Code: IR.KUMS.MED.REC.1403.013). All participants provided informed consent to participate in the research.

Consent to publish

Not applicable.

Competing interest

The authors declare no competing interests.