Effect of hypnosis on psychological distress in female university students with premenstrual syndrome

Abstract

Objectives

This study aimed to investigate the effect of hypnosis on psychological distress in female university students with premenstrual syndrome.

Methods

In this parallel randomized controlled trial (1:1), 60 eligible female students with premenstrual syndrome in the dormitories of Kermanshah University of Medical Sciences (west of Iran), were selected randomly and allocated to the experimental, and control groups (n = 30 each), using a simple randomization method. The experiment group received a structured hypnosis intervention consisting of three 60-min group sessions conducted weekly, and no intervention was performed in the control group. Before, the intervention, two groups completed premenstrual syndrome screening and DASS-21 questionnaire. The DASS-21was completed after the intervention (three months after the last intervention session), by two groups. In this study, the participants and investigators were not blinded; however, the analysts were. The recruitment process took place from October to December 2020. Sixty participants fulfilled the study. The collected data were analyzed using SPSS (v24).

Results

After the intervention, the total mean scores for depression (3.40 ± 4.08 vs. 7.40 ± 3.15; mean difference: − 4.000 [95% CI − 5.566, − 2.434]; p < 0.0001), anxiety (2.67 ± 2.15 vs. 4.40 ± 2.72; mean difference: − 1.733 [95% CI − 2.924, − 0.543]; p = 0.004), and stress (4.63 ± 3.16 vs. 9.30 ± 2.57; mean difference: − 4.667 [95% CI − 6.159, − 3.175]; p < 0.0001) were significantly lower in the hypnosis group compared to the control group. No significant adverse events or side effects were observed.

Conclusion

Hypnotherapy relaxation among female students experiencing premenstrual syndrome resulted in reduction in symptoms of depression, stress, and anxiety but a larger sample size is required to fully test its merits.

Trial Registration Clinical Trials: Iranian Registry of Clinical Trials; https://irct.behdasht.gov.ir/trial/50699 (IRCT20151208025433N5), registered (2020-09-27). Registration timing: retrospective.

Introduction

Premenstrual syndrome (PMS) is characterized by a cluster of physical, emotional, and behavioral symptoms that arise due to hormonal fluctuations during the menstrual cycle [1].

The symptoms of PMS regularly occur during the luteal phase of the menstrual cycle and resolve by the end of menstruation [2].

PMS is associated with a range of emotional symptoms (e.g., irritability, anxiety, depression, mood swings) and physical symptoms (e.g., breast tenderness, bloating, headaches, fatigue). Many women experience these changes in the days before menstruation [3].

Research indicates that the prevalence of PMS varies across countries, affecting approximately 58.1% of women in Turkey, 64.2% of women in Brazil, and 56% of women in Iran [4–6].

It has been found that the estrogen hormone directly affects brain functions related to women’s affective and cognitive states, which are believed to be responsible for mood changes and cognitive functions. Studies have shown that estrogen levels are high during the follicular phase and low during the luteal phase. Accordingly, fluctuations in estrogen levels between the luteal and follicular phases lead to changes in cognitive skills and abilities, as well as variations in mood states [7]. Gamma-aminobutyric acid (GABA) and the autonomic nervous system also play a role in the pathogenesis of PMS [8].

In recent years, various studies have focused on the effectiveness of non-pharmacological methods in managing the symptoms of PMS [9–12]. Various mind–body interventions have also attracted the attention of specialists [13]. Hypnosis is one of the types of mind–body interventions. Hypnosis has been applied extensively to numerous medical and psychological conditions [14]. The effectiveness of hypnotherapy in facilitating the acceptance of new feelings and thoughts makes it suitable for treating habitual problems and controlling symptoms. Conditions such as smoking, overeating, anxiety, fears, conversion symptoms, and chronic pain can all be treated with hypnotherapy [15].

Asgariani et al. demonstrated that hypnosis was highly effective in alleviating PMS symptoms, with participants showing a significant reduction in symptom severity. Moreover, they reported that hypnosis was more effective than relaxation techniques [16]. Ramondo et al. found that adding hypnosis to CBT is more effective in improving major depressive disorder than cognitive-behavioral therapy alone [17].

Pourhamidi et al. found that cognitive behavioral hypnotherapy was more effective than cognitive-behavioral therapy in reducing anxiety [18]. Roberts et al. found that Hypnosis reduced symptoms of anxiety among postmenopausal women [19].

Given the limitations and side effects associated with pharmacological treatments, as well as the growing interest in physiological interventions to improve mental health, the present study was conducted to examine the effect of hypnosis on psychological distress in female university students with premenstrual syndrome. We hypothesized that female university students with premenstrual syndrome who receive hypnosis will have a lower degree of depression, anxiety, and stress symptoms than those in a control group.

Methods

Study setting, design, and participants

The study was conducted as a confirmatory randomized clinical trial with a control group, employing a pretest–posttest design. The level of the trial was established a priori based on the existing evidence supporting the potential psychological benefits of hypnosis and the need to formally test its effectiveness in a controlled setting. The study employed a predefined hypothesis, validated outcome measures, and a structured intervention protocol consistent with the characteristics of confirmatory clinical research.

The study population consisted of all female students living in the dormitories of Kermanshah University of Medical Sciences in 2020.

To recruit participants, all female students residing in the dormitories of Kermanshah University of Medical Sciences were initially screened using the Premenstrual Symptoms Screening Tool (PSST).

120 individuals were diagnosed using the PSST. Then, a list of 120 students identified with PMS was prepared alphabetically, and 60 individuals who met both inclusion and exclusion criteria, were randomly chosen from these lists using a random number table and subsequently randomly assigned into either the control group (n = 30) or the experimental group (n = 30) (Fig. 1).

Fig. 1.

CONSORT flochart of the study

To control the obtrusive variables, we matched the groups in terms of demographic variables.

The study reporting followed the Consolidated Standards of Reporting Trials (CONSORT) 2010 guidelines. The recruitment process took place from October to December 2020.

Sample size calculation

To determine the sample size, the formula for comparing two means was used based on stress outcomes reported in Sharifirad et al. [11]. Considering the post-intervention values reported in Sharifirad study, 13.85 ± 2.86 for the intervention group and 16.22 ± 1.98 for the control group were applied. Accordingly, the sample size—taking into account a 95% confidence interval and 90% test power— initial sample size was calculated to be 46 participants (23 in the hypnosis group and 23 in the control group). To account for potential dropouts, a 10% attrition rate was added. Additionally, to improve the statistical power and ensure the robustness of the findings, the final sample size for both the experimental and control groups was increased to 30 participants each, resulting in a total sample of 60. This number was documented in the study protocol and maintained throughout the research, ensuring adequate power to detect meaningful differences between the intervention and control groups.

In this equation, the parameters were set as follows: α = 0.05, β = 0.10, δ₁ = 1.98, δ₂ = 2.86, μ₁ = 16.22, and μ₂ = 13.85.

Inclusion and exclusion criteria

The inclusion criteria for participants were as follows: aged 18–27 years; regular menstruation cycles (26–31 days duration); normal menstrual flow duration (3–8 days); PSST score ≥ 18 (indicating moderate-to-severe PMS); anxiety subscale score between 8 and 14 (mild-to-moderate), depression subscale score between 10 and 20 (mild-to-moderate) and stress subscale score between 15 and 25(mild-to-moderate).

The exclusion criteria for participants comprised a history of smoking or narcotic use; a history of ovarian cysts or reproductive system surgery; a history of underlying diseases known to affect PMS symptoms (such as cardiac, respiratory, or renal diseases, hypertension, asthma, diabetes, epilepsy, migraine, thyroid disorders, anemia, and neuropsychological disorders); a history of mental illness or depression; prior use of antidepressants, tranquilizers, or hormonal medications; experiencing significant life events such as the loss of loved ones or divorce within the past three months; and a diagnosis of premenstrual dysphoric disorder (PMDD).

Randomization

To recruit participants, all students residing in the dormitories of Kermanshah University of Medical Sciences were initially screened using the Premenstrual Symptoms Screening Tool (PSST). A total of 120 individuals were diagnosed using the PSST. Then, a list of 120 students identified with PMS was prepared alphabetically, and 60 individuals who met both inclusion and exclusion criteria, were randomly chosen from these lists using a random number table and subsequently randomly assigned into either the control group (n = 30) or the experimental group (n = 30) in a 1:1 ratio using a simple randomization method by a third party uninvolved in the study (Fig. 1).

The randomization sequence was concealed from the researcher responsible for enrolling participants. To ensure this, 60 identical cards numbered 1–60 were prepared: odd-numbered cards assigned participants to the hypnosis group, while even-numbered cards assigned them to the no-intervention (control) group. Eligible participants drew one card blindly to determine their group, maintaining allocation concealment. Participants were not informed of the allocation method at any point during the study.

The groups were classified based on randomized allocation using simple randomization. This approach aligns with a similar previous study [20].

The intervention was administered by the third author. A third-party, blinded to the group allocation, was trained to collect data. In this study, neither the participants nor the investigators were blinded; however, the analysts were unaware of group assignments during data analysis. To minimize bias and control the exchange of information between the two groups, participants in the control group were selected from one dormitory, while those in the intervention group were selected from another dormitory.

Measures

The Premenstrual Syndrome Screening Tool (PSST) was employed for case confirmation, selected for its established validity, reliability, and efficiency in clinical screening. This 19-item instrument utilizes a 4-point Likert scale assessing symptom severity (0 = absent, 1 = Mild, 2 = Moderate, and 3 = Severe). A total score ≥ 18 served as the diagnostic threshold for PMS classification. The PSST has demonstrated excellent psychometric properties in the Iranian population, with a reported Cronbach’s alpha coefficient of 0.93 [21]. In the present study, the reliability of the questionnaire was assessed using the Cronbach’s alpha, resulting in values of 0.78.

Depression, stress, and anxiety levels were measured using the questionnaire (DASS-21). The DASS21, an evaluation tool for assessing depression, anxiety, and stress, was created in 1995 and comprises 21 items [22]. Items 3, 5, 10, 13, 16, 17, and 21 measure depression; items 2, 4, 7, 9, 15, 19, and 20 measure anxiety; and items 1, 6, 8, 11, 12, 14, and 18 measure stress. The DASS21 has been psychometrically validated in Iran, and Cronbach’s alpha reported as 0.79 for the anxiety subscale, 0.91 for stress, and 0.93 for depression, respectively [23].

In the present study, the reliability of the questionnaire was assessed using the Cronbach’s alpha, resulting in values of 0.86.

The questionnaire (DASS-21) was completed before and after the intervention (three months after the last intervention session), by two groups.

Intervention section

The intervention consisted of a structured, manualized group hypnotherapy program delivered over three weekly sessions, each lasting 60 min. Participants were randomly assigned to either the experimental group, which received the hypnotherapy intervention, or the control group, which received no active treatment during the study period but were offered one compensatory session afterward.

A total of 30 participants were divided into three groups (10 students per group). Sessions were administered by the third author, a PhD holder in psychology certified by the Iranian Clinical Hypnotism Scientific Association. All sessions took place in a dedicated hall within the university dormitory to ensure participant accessibility. Attendance was recorded for each session, and all participants completed the entire program without attrition.

The sessions covered the following topics:

Session 1: Psychoeducation and orientation.

The first session included: Psychoeducation on PMS, emphasizing both physiological and psychological symptom mechanisms. Orientation to hypnotherapy, including its goals for relaxation and symptom regulation. Treatment plan explanation, covering session frequency, duration, and participant expectations.

The hypnotherapist also introduced the concept of trance, addressed common misconceptions, and explained the role of focused attention in symptom management.

Session 2: Induction and therapeutic suggestions.

The second session began with reviewing participants’ practice experiences and addressing any concerns. Then, a standardized hypnotic induction was conducted, consisting of eye fixation, progressive muscle relaxation, and guided imagery. Deepening techniques, such as counting backward and focused breathing, were applied according to each participant’s responsiveness.

Once a trance state was achieved (confirmed through behavioral cues such as slowed breathing, facial relaxation, and subjective feedback), the hypnotherapist delivered a series of standardized therapeutic suggestions, including: “Your body and mind are entering a state of calm and balance.” “Each menstrual cycle, you will notice your symptoms becoming lighter and more manageable.” “You have the ability to control your focus and relax whenever you choose.”

Positive visualizations (e.g., imagining a warm, soothing light spreading through the body) were used to reinforce the suggestions. The session concluded with reorientation to full wakefulness.

Session 3: Self-hypnosis training and consolidation.

The final session focused on teaching self-hypnosis techniques to promote independent use after the intervention. Participants were trained in self-induction using relaxation and imagery cues, followed by personalized positive suggestions. Each participant practiced under supervision to ensure correct application.

Participants were instructed to practice self-hypnosis twice per week during the three-week intervention and throughout the three-month follow-up period. A researcher contacted participants weekly by phone to encourage adherence and address potential difficulties.

To ensure treatment fidelity, the hypnotherapist followed a written session manual. A second researcher (independent observer) attended 20% of randomly selected sessions using a standardized fidelity checklist evaluating adherence to induction steps, suggestion content, session structure, and timing. Deviations were discussed in supervision meetings to maintain protocol consistency.

Three months after the last session, participants completed the DASS-21 again (post-test).

Outcome measures

Primary outcome

Depression, anxiety and stress, before and after the completion of the intervention, the depression, anxiety, and stress scale (DASS21) was completed by the participants of the two groups.

Harms/adverse events section

One of the researchers made phone calls to the participants to check for any adverse effect and no significant adverse events or side effects were observed.

Statistical analysis

The statistical analysis utilized the Statistical Package for the Social Sciences (SPSS), version 25.0. The Kolmogorov–Smirnov (KS) test determined the normality of data distribution. Mean and standard deviation were used to describe quantitative variables. Paired.

t-test and Wilcoxon Signed Ranks test was used to evaluate within-group differences. To examine the mean scores of depression, anxiety, and stress before, and after the intervention between two groups, Independent t-test and Mann–Whitney test was employed.

Due to the significance difference in baseline anxiety scores between the two groups, ANCOVA was used to determine the effect of this covariate on the post-intervention anxiety scores. A significance level, or p-value, of less than 0.05 was set for all analyses.

The within-group analyses were conducted to explore pre–post changes within each group as an additional descriptive analysis. However, between-group comparisons remain the main analytic approach.

Protocol deviations

The study was conducted in accordance with the registered protocol; however, a few minor deviations occurred during implementation. First, due to scheduling difficulties among participants during academic examination periods, data collection was delayed beyond the originally planned timeline. Second, the primary outcome of the study—initially limited to depression—was expanded to include depression, anxiety, and stress to provide a more comprehensive assessment of emotional symptoms associated with Premenstrual Syndrome. Finally, the timing of the post-test assessment was modified from two weeks after the intervention to three months after the last hypnosis session in order to evaluate the more sustained effects of the intervention. These modifications did not affect the intervention procedures, randomization process, or the integrity of the outcome assessments.

Results

A total of 120 individuals were screened for eligibility, of whom 60 met inclusion criteria and were enrolled in the study. Participants were randomly assigned to either the experimental or control group (n = 30 per group). No attrition occurred during follow-up, resulting in complete data from all 60 enrolled participants being included in the final analysis (Fig. 1).

Table 1, lists the individual characteristics of the two groups. As listed, there are no meaningful differences between groups due to individual characteristics (p > 0.05).

Table 1.

Individual characteristics of female university students in the two groups

Variables		Intervention N = 30 Mean ± SD Or N (%)	Control N = 30 Mean ± SD Or N (%)	p-value
Age (years)		23.53 ± 5.04	25.60 ± 7.00	0.439*
Education level	Undergraduate	21 (70.0)	24 (80.0)	0.371**
	Postgraduate	9 (30.0)	6 (20.0)
Major	Clinical	22 (73.3)	17 (56.7)	0.176**
	Basic Sciences	8 (26.7)	13 (43.3)
Marital Status	Single	26(86.7)	25 (83.3)	1.000***
	Married	4 (13.3)	5 (16.7)

^*Mann–Whitney test

^**Chi-Square test

^***Fisher Exact test

The experimental group demonstrated significant improvements across all measured psychological outcomes. Depression scores decreased from 7.97 ± 4.08 at baseline to 3.40 ± 2.94 post-intervention (p = 0.001, paired t-test). Similarly, anxiety scores showed significant reduction from 6.33 ± 3.42 to 2.67 ± 2.15 (p = 0.001). Stress levels also improved significantly, declining from 9.70 ± 4.70 to 4.63 ± 3.16 (p = 0.001). As shown in Table 2, paired t-test or Wilcoxon Signed Ranks test revealed significant reductions in both anxiety and stress scores following the intervention (p < 0.05) (Table 2).

Table 2.

Mean scores of depression, anxiety, and stress in the two groups

Variable	Group	Pretest		Posttest		T	P-value
		Mean	SD	Mean	SD
Depression	Hypnotherapy	7.97	4.08	3.40	2.94	9.68	0.001*
	Control	7.60	3.15	7.40	3.11	1.18	0.246*
Anxiety	Hypnotherapy	6.33	3.42	2.67	2.15	4.72	0.001**
	Control	4.43	2.72	4.40	2.44	0.47	0.717**
Stress	Hypnotherapy	9.70	4.70	4.63	3.16	7.32	0.001*
	Control	8.87	2.52	9.30	2.57	− 1.71	0.103**

^*Paired t-test

^**Wilcoxon signed ranks test

Paired t-tests or Wilcoxon Signed Ranks test revealed no statistically significant changes in the control group across all measures. Depression scores remained stable (pre: 7.60 ± 3.15 vs. post: 7.40 ± 3.15; p = 0.246), as did anxiety scores (pre: 4.43 ± 2.72 vs. post: 4.40 ± 2.72; p = 0.717). Stress scores showed a marginal increase from 8.87 ± 2.52 to 9.30 ± 2.57, though this change was not statistically significant (p = 0.097) (Table 2). As presented in Table 2, Wilcoxon Signed Ranks test or Paired t-test indicated no significant differences in anxiety (p = 0.879) or stress scores (p = 0.097) between baseline and post-intervention assessments in the control group (p ≥ 0.05).

As shown in Table 3, the mean ± SD of pre-intervention depression in the experimental group was 7.97 ± 4.08, and in the control group, it was 7.60 ± 3.15. An independent t-test showed no significant difference between the groups (p = 0.699). The mean ± SD of pre-intervention stress in the experimental group was 9.70 ± 4.70, and in the control group, it was 8.87 ± 2.52. A Mann–Whitney test indicated no significant difference between the groups (p = 0.385). The mean ± SD of pre-intervention anxiety in the experimental group was 6.33 ± 3.42, and in the control group, it was 4.43 ± 2.72. The Mann–Whitney test showed a significant difference between the groups (p = 0.022).

Table 3.

Mean and standard deviation of depression, anxiety, and stress scores before, and after the intervention in the two groups

Variable	Time	Hypnotherapy	Control	Mean difference(95%CI)	P value
		M ± SD	M ± SD
Stress	Pretest	9.70 ± 4.70	8.87 ± 2.52	0.833 (− 1.132, 2.799)	0.385*
	Posttest	4.63 ± 3.16	9.30 ± 2.57	− 4.667 (− 6.159, − 3.175)	< 0.0001*
Anxiety	Pretest	6.33 ± 3.42	4.43 ± 2.72	1.900 (0.300, 3.500)	0.022*
	Posttest	2.67 ± 2.15	4.40 ± 2.44	− 1.733 (− 2.924, − 0.543)	0.004*
Depression	Pretest	7.97 ± 4.08	7.60 ± 3.15	0.367 (− 1.522, 2.255)	0.699**
	Posttest	3.40 ± 2.94	7.40 ± 3.11	− 4.000 (− 5.566, − 2.434)	< 0.0001**

^*Mann–Whitney test

^**Independent t-test

After the intervention, the total mean scores for depression (3.40 ± 4.08 vs. 7.40 ± 3.15; mean difference: − 4.000 [95% CI − 5.566, − 2.434]; p < 0.0001), anxiety (2.67 ± 2.15 vs. 4.40 ± 2.72; mean difference: − 1.733 [95% CI − 2.924, − 0.543]; p = 0.004), and stress (4.63 ± 3.16 vs. 9.30 ± 2.57; mean difference: − 4.667 [95% CI − 6.159, − 3.175]; p < 0.0001) were significantly lower in the hypnosis group compared to the control group (Table 3).

The results of the ANCOVA showed that, after controlling for baseline anxiety scores as a covariate, there was a statistically significant difference in post-intervention anxiety scores between the two groups (p = 0.008).

The mean PSST score before the intervention was 29.87 ± 8.33 in the intervention group and 29.47 ± 6.12 in the control group, with no statistically significant difference between the two groups (p = 0.833). However, following the intervention, the mean PSST score decreased to 14.27 ± 6.60 in the intervention group and was 29.83 ± 5.79 in the control group, demonstrating a statistically significant difference between the groups (p < 0.001). These results indicate substantially greater improvement in the intervention group compared to the control group.

Discussion

The present study suggests that hypnosis may alleviate symptoms of stress, anxiety, and depression among female university students with premenstrual syndrome. These findings are consistent with previous research reporting beneficial effects of hypnotherapy on psychological symptoms in various populations. For example, Moghtader et al. found that cognitive hypnotherapy was associated with a reduction in depressive symptoms among individuals with PMS compared to controls [20]. Similarly, Asghariani et al. observed significant reductions in PMS symptoms—including irritability, nervous tension, and low mood—following standard hypnotism compared to muscle relaxation [16]. Other studies have reported improvements in pain intensity and emotional distress when hypnotherapy incorporated cognitive flexibility and ego-strengthening suggestions [24], and relaxation-based hypnotherapy and virtual reality interventions have also been shown to reduce PMS symptoms [25].

Beyond PMS, evidence supports the broader anxiolytic and stress-reducing effects of hypnosis. Studies have shown that hypnosis is associated with reduced anxiety and pain in dental patients [26], as well as decreased competitive anxiety among athletes [27, 28].

In a review study, Leo et al. suggested that hypnosis and hypnotherapy are effective treatments for anxiety and may exert beneficial effects on the heart and cardiovascular system by reducing sympathetic activation and enhancing parasympathetic tone. These effects may, in turn, help prevent cardiovascular diseases linked to increased sympathetic activity [29].

Similarly, Seitz et al. proposed the integration of hypnotherapy as an adjunctive therapeutic approach to alleviate anxiety and mitigate symptoms associated with preeclampsia [30].

Furthermore, a recent meta-analysis of 17 trials investigating the role of hypnosis in managing various forms of anxiety (e.g., general, performance, dental, and medical/surgical anxiety) demonstrated that patients treated with hypnosis achieved greater anxiety reduction than 84% of participants in control groups who did not receive hypnosis [31].

Although these studies differ in population and design, they collectively support the possibility that hypnosis can influence both psychological and physiological processes relevant to PMS symptomatology.

Several mechanisms may underlie these effects. Psychologically, hypnosis may help restore a healthier mind–body connection, allowing individuals to achieve deeper relaxation and emotional regulation [20, 32].

Biologically, modulation of norepinephrine sensitivity during the luteal phase [33, 34], changes in anterior cingulate cortex activity [35], and increased endorphin secretion [36] have been proposed as potential pathways through which hypnosis may reduce premenstrual symptoms. However, these mechanisms remain largely hypothetical and warrant direct investigation.

Strengths and limitations of the study

This study has several strengths. Random assignment of participants to control and experimental groups enhanced internal validity, while full participant retention ensured completeness of data. All hypnotherapy sessions were delivered by a licensed psychologist with a PhD in clinical psychology and formal certification in hypnotherapy, ensuring treatment fidelity.

However, several limitations should be considered. The sample was restricted to dormitory students from universities in Kermanshah, which may limit generalizability to other populations. Neither participants nor researchers were blinded, increasing the risk of performance and detection bias. while the DASS-21 demonstrates strong psychometric properties as a screening tool, its reliance on self-reported measures of symptoms of depression, anxiety, and stress introduces the possibility of subjective response bias.

Outcomes were assessed only once at the three-month post-test, preventing evaluation of the long-term sustainability of effects. The control group received no intervention, raising the possibility that observed improvements were influenced by non-specific factors such as expectancy or group dynamics. Logistical constraints prevented immediate post-intervention assessments. The sample size was small (n = 60), reducing statistical power and increasing the risk of Type I and Type II errors. Students diagnosed with PMDD were excluded, limiting the applicability of results to this subgroup.

Future studies should include larger, more diverse samples, active or placebo control groups, and multiple follow-up assessments to enhance internal and external validity. Incorporating objective behavioral and physiological measures alongside self-reported outcomes would also strengthen the robustness of findings. Despite these limitations, the study provides preliminary evidence supporting the potential benefits of hypnosis in reducing stress, anxiety, and depression among female university students with premenstrual syndrome.

Conclusion

While hypnotherapy appears to be effective in reducing the psychological symptoms of PMS in this student population, more rigorous research with larger and more diverse samples is needed to confirm these preliminary findings. Larger multicenter studies with longer follow-up periods are recommended to assess sustained effects. The use of objective physiological measures (such as cortisol levels and hormone tests) in addition to psychological assessments is also suggested. It would also be useful to compare hypnotherapy with other interventions (such as cognitive-behavioral therapy or pharmacotherapy) in randomized controlled designs. The data from this study may be particularly applicable to young women in academic settings who suffer from PMS-related distress, populations with limited access to pharmacological treatments, and patients who prefer to use no pharmacological interventions. Future cross-cultural research should evaluate the efficacy of hypnotherapy for PMS, taking into account cultural influences on symptom perception and treatment adherence.

Abbreviations

NSAIDs

Nonsteroidal anti-inflammatory drugs

PMS

Premenstrual syndrome

DASS21

Depression anxiety stress scale

PSST

Premenstrual syndrome screening tool

GnRH

Gonadotropin-releasing hormone

Author contributions

S. H: conceptualization; methodology; project administration; supervision; visualization; writing, review, and editing. Y. Torabi: investigation; methodology; writing the original draft. F. D: methodology; writing, review, and editing. F. H: formal analysis; methodology; validation. All authors thoroughly read and approved the manuscript.

Funding

This research was funded by the Kermanshah University of Medicine Science. The funder did not have any role in the design of the study; collection, analysis, and interpretation of data; or writing of the manuscript.

Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

This study was approved by the Ethical Committee of the Kermanshah University of Medicine Science (approval number IR.KUMS.REC.1399.520) and In addition the study is registered with Clinical Trial Registration Center under the code: IRCT20151208025433N5. The participants were fully briefed on the study objectives and procedures and, and their informed written consent was obtained. They were assured that their information would remain confidential and that they could withdraw from the study at any stage of the research. No compensation (money or item), was provided to the research participant. The study was conducted in accordance with the Declaration of Helsinki and subsequent. The research objectives were explained to the participants, and informed written consent was obtained from them.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.