This study employs a systematic review design method, a secondary research approach that synthesises existing literature to answer research questions about suicidality in women with Premenstrual Dysphoric Disorder (PMDD). The study adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to ensure effective reporting, with validation from previous studies [20] [21] . The systematic review process consists of eight key steps:

This systematic review design is deemed the most suitable method for this research as it enables the comprehensive evaluation of individual studies regarding suicidality risks in women with PMDD. The method enhances the study’s accuracy, reproducibility, and potential for future updates [21] [22] . The structured approach makes the study reliable and valuable for future research and clinical practice.

The first step in the systematic review is to perform preliminary checks to ensure the relevance of the research topic. Existing studies will be identified and assessed based on their ability to answer the research questions.

This study will only consider articles published between January 2008 and April 2023, ensuring that the research reflects the latest studies, with a focus on the period following the inclusion of PMDD in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013.

As shown in Table 1 , Keywords such as “Premenstrual Dysphoric Disorder” (PMDD) and “suicidality” will be searched in study titles and abstracts. Boolean operators (“AND” and “OR”) will be used to combine keywords, such as (“Premenstrual Dysphoric Disorder” OR “PMDD”) AND “Suic*”. In databases that do not recognise truncated words, terms like “suicide,” “suicidal,” or “suicidality” will be used.

The SPIDER framework (Sample, Phenomenon of Interest, Design, Evaluation, Research type) will guide the creation of these criteria [23] [24] . The SPIDER framework ensures that the selected studies are relevant and focused on the research elements most pertinent to the study.

The Inclusion criteria for this study are:

1) Sample: studies that have included women of childbearing age across the globe.

2) Phenomenon of interest: studies that include data on women who experience PMDD.

3) Design: Various quantitative study designs will be included.

4) Evaluation: Studies which provide data on the prevalence or incidence of suicidality in PMDD, describe the experiences of suicidality in women with PMDD, or provide insight into the mechanism of suicidality in women with PMDD.

5) Research type: Qualitative, quantitative, or mixed methods and cross-sectional studies.

Exclusion Criteria:

1) Systematic reviews, commentaries, and meta-analyses;

2) Studies published before 2008;

3) Non-English publications;

4) Studies not reporting on suicidality as a primary or secondary outcome;

5) Trials lacking DSM/clinical diagnosis of PMDD.

A systematic literature search will be conducted once the inclusion and exclusion criteria are defined. The search will include databases focused on health-related issues, particularly those with titles pertinent to PMDD and suicidality.

All search results will be retrieved and managed using a reference management software to de-duplicate studies. Studies that meet the inclusion criteria will be selected for further analysis, ensuring that only relevant studies are included and thereby refining the research to answer the research questions effectively.

Data extraction will be done using systematic review software, ensuring that relevant information from the selected studies is accurately collected. This step is critical to synthesising the findings from individual studies and contributing to a comprehensive review of the topic.

The quality appraisal of selected studies will be conducted using the Critical Appraisal Skills Programme (CASP) tool, which helps assess the validity and trustworthiness of qualitative research. The CASP tool includes ten questions to evaluate the study’s validity, results, and relevance. The tool will guide the selection of studies with acceptable relevance (7 out of 10), ensuring that only high-quality studies are included in the final review [25] .

The quality and relevance of the selected studies will be evaluated and appraised using the Critical Appraisal Skills Programme (CASP) tool, which is widely used for evaluating qualitative research [25] . CASP includes ten questions assessing each study’s validity, results, and local applicability.

The study will employ a narrative synthesis approach to present the findings. A narrative synthesis allows for the grouping, summarising, and interpreting of data from qualitative and quantitative studies [26] [27] . The narrative synthesis will provide detailed insights into the experiences of women with PMDD, focusing on the association with suicidality. The approach will also highlight research gaps and limitations within the reviewed studies.

Given the heterogeneous nature of this study, which includes both qualitative and quantitative research, a narrative synthesis approach will be employed. This approach suits diverse study outcomes and allows grouping, summarising, and interpreting the findings [26] [27] . A narrative synthesis has been used successfully in previous systematic reviews on PMDD [28] . The narrative synthesis will provide detailed reports that contribute to understanding women’s experiences with PMDD and suicidality.

A meta-analysis will not be conducted due to the heterogeneous nature of the studies included in the review. This diversity in study outcomes renders it unsuitable for statistical pooling; therefore, the narrative synthesis approach will focus on qualitative and descriptive reporting.

A systematic search using key terms yielded 52 studies from several selected databases, including Web of Science (n = 23), Medline (n = 17), ScienceDirect (n = 10), and EBSCOhost (n = 2). After removing 22 duplicates, 30 studies remained for the title and abstract screening, excluding 10 articles due to irrelevance. Applying the inclusion and exclusion criteria, 13 other studies were excluded, including systematic reviews, meta-analyses, non-English articles, older studies, and trial-based studies. This left seven studies included in this review, published between 2011 and 2022, focusing on the relationship between PMDD and suicidality.

The selection process of studies included in this review is illustrated in Figure 1 .

The studies were conducted in various countries, including the United States, Nigeria, Brazil, France, Iran, South Korea, and South Korea. The methodologies included cross-sectional studies [9] [17] [29] , a randomised demographic study [12] , and cohort and control studies [10] [11] [18] . The studies included participants from different age ranges (13 - 64 years), ethnic backgrounds, and varied sample sizes ranging from 120 to 3965. All seven studies found a strong association between PMDD and suicidality, revealing that women with PMDD face a significantly higher risk of suicide compared to women without PMDD.

Table 2 summarises the characteristics of the seven studies included in this review.

As seen in Table 2 , Publication dates from the seven included studies ranged from 2011 to 2022; this indicates that the studies are up to date and in line with the inclusion criteria, which require studies to be less than 15 years old. Two studies were conducted in the United States of America [11] [29] . One of the two studies also recruited participants from Nigeria (N = 11). One of the studies was conducted online, using randomised online sources [12] . And one each in the following countries: Brazil [9] , France [18] , Iran [10] , and South Korea [17] .

Three out of seven of these studies were cross-sectional [9] [17] [29] . One of the studies was a randomised demographic study [12] . The other three studies were cohort and control studies [10] [11] [18] . All seven studies were a combination of both qualitative and quantitative research methods. The main objectives of each study were to identify the relationship between PMDD and suicidality. All seven studies assessed the association between suicidality and PMDD. And all seven studies revealed a close association between suicidality and PMDD.

These seven studies included participants from various age groups, ranging from 13 to 64 years, and women from different racial backgrounds, including Black women, White women, and Hispanic women. The sample sizes ranged from 120 participants to 3965 participants.

The outcomes of all seven studies were similar; they all revealed a significant positive relationship between suicidality and PMDD. There is a higher suicide risk in women with PMDD when compared with women without PMDD. Some studies also showed a close link between PMDD and other psychiatric mood disorders. All seven studies were appraised using the CASP tool, and the quality of the studies ranged from very good to excellent.

The studies collectively suggest that PMDD is significantly associated with suicidality, with several studies investigating different factors such as age, race, and economic background. Ogebe et al. [11] found that adolescents experiencing PMDD were more likely to have suicidal ideation, with a cultural element affecting the prevalence of PMDD and suicidality. The study, conducted in Nigeria and the United States, revealed that adolescents were more susceptible to PMDD than older women.

Similarly, Hong et al. [17] reported that the highest prevalence of PMDD occurred in young women aged 18 - 29 years. Their study, conducted in South Korea, also found that women with PMDD were significantly more likely to experience suicidal ideation compared to those without PMDD. However, Hong et al. [17] found no association between suicidality and factors such as financial status, occupation, or education.

In Brazil, De Carvalho et al. [9] found that PMDD was more common among older women (17.6%). This study also confirmed that women with PMDD were at higher risk for suicidality, especially those from lower socioeconomic backgrounds. These findings align with those of Ogebe et al. [11] , which also showed that lower socioeconomic status contributed to higher risks of suicidality in women with PMDD.

Shams-Alizadeh et al. [10] focused on women who had attempted suicide, comparing them to a control group of women without suicidality. The study revealed a significant association between PMDD and suicide attempts. However, it did not find a link between economic status and suicidality, differing from the findings of Ogebe et al. [11] and de Carvalho et al. [9] .

In a randomised demographic study, Eisenlohr-Moul et al. [12] surveyed 2698 online participants from organisations focusing on PMDD. The study found that women with PMDD, especially those with low incomes, had higher rates of suicidal ideation and suicide attempts. The study also highlighted that older women with PMDD faced increased risks due to a lack of early diagnosis and treatment.

Ducasse et al. [18] found that women with PMDD were more likely to experience mood instability, anger, and hostility, traits often associated with suicidality. The study, conducted in France, reported that 23% of women who attempted suicide were diagnosed with PMDD. It emphasised the importance of addressing other psychiatric conditions that might co-occur with PMDD.

Pilver et al. [29] , conducted in the United States with 3965 participants, also revealed a significant relationship between PMDD and suicidality. Women with PMDD were found to have higher rates of suicidal ideation, plans, and attempts compared to those without PMDD. The study also noted that race and ethnicity played a significant role in suicidality in PMDD, a finding similar to that of Ogebe et al. [11] .

All seven studies assessed PMDD alongside other psychiatric conditions, often using structured clinical interviews based on DSM-IV criteria. For example, Ogebe et al. [11] and de Carvalho et al. [9] utilised the MINI (Mini International Neuropsychiatric Interview) for psychiatric diagnosis. In contrast, Hong et al. [17] employed the WHO Composite International Diagnostic Interview. Other studies, such as Ducasse et al. [18] and Pilver et al. [29] , utilised the World Mental Health Composite International Diagnostic Interview for PMDD diagnosis. These studies consistently found that PMDD often co-occurs with other psychiatric disorders, which may exacerbate the risk of suicidality.

The seven studies consistently found a significant association between PMDD and suicidality. Suicidality was categorised into suicidal ideation, plans, and attempts, and the studies investigated these aspects using structured clinical psychiatric interviews, hospitalisation data, and standardised questionnaires. Four studies [10] [17] [18] [29] focused on suicide attempts, while three studies [9] [10] [12] examined suicidal ideation and plans. All studies indicated that women with PMDD were at a higher risk of suicidality.

Three studies explored the relationship between the menstrual cycle and suicidality in women with PMDD. While Ducasse et al. [18] and Shams-Alizadeh et al. [10] found no clear link, Ogebe et al. [11] reported that suicidality risk was heightened during the menstrual cycle for women with PMDD. This finding suggests that the timing of PMDD symptoms may influence the severity of suicidality in some women.

All seven studies investigated the prevalence of PMDD, with varying results based on factors such as age and socioeconomic status. Studies by Ogebe et al. [11] , Hong et al. [17] , de Carvalho et al. [9] , and Eisenlohr-Moul et al. [12] found that PMDD was prevalent across different age groups, with some studies indicating higher rates in younger women [17] , while others reported higher prevalence in older women [9] [12] . Social and economic factors also played a role in the prevalence and severity of PMDD, with lower-income women at higher risk for both PMDD and suicidality.

All seven studies analysed and examined the characteristics of women with PMDD. Findings from all studies revealed severe depression as one of the significant characteristics of women with PMDD. Results from the survey by Ducasse et al. [18] showed anger as a substantial characteristic of women with PMDD. Other characteristics of women with PMDD revealed in the studies include mood instability [11] . The different studies highlighted other factors such as hopelessness, irritability, paranoia, loss of interest in activities and eating disorders.

In conclusion, all seven studies affirmed a strong link between PMDD and suicidality, with variations in findings related to age, race, socioeconomic status, and other psychiatric conditions. Women with PMDD were found to have a significantly higher risk of suicidal thoughts, plans, and attempts, highlighting the importance of early diagnosis and appropriate interventions for this population.

The combined findings of all included studies are found in Table 3 .

Table 3 combined findings of included studies show the relationship between PMDD and Categories of Suicidality.

A global approach should be adopted to reduce suicide risks in women with PMDD. Simpler diagnostic methods need to be developed; This will make treatments more accessible and affordable. Establishing simple diagnostic methods will aid early detection. More education and enlightenment are necessary about PMDD, especially for young girls. Further research is needed to understand the causal mechanisms of PMDD, which would inform the development of preventive measures. Additionally, supporting women with PMDD, such as offering menstrual leave, could help reduce work-related stress, and this needs to be encouraged.

This research is relevant and timely, addressing a global health issue—the systematic review synthesised evidence from various studies, providing a comprehensive analysis of suicidality in PMDD. The research involved large sample sizes and represented global evidence on the topic. This work lays the foundation for future studies on suicidality in women with PMDD.

The short timeframe for the study limited the depth of research. The available studies on suicidality and PMDD were limited, and many diagnoses were retrospective or provisional. The inclusion criteria excluded studies older than 15 years, potentially missing relevant research. Some regions, such as Africa, had limited representation, and there was no data on completed suicides related to PMDD, making it difficult to estimate how many women die by suicide due to this condition.