The Association Between Neuroticism and Premenstrual Syndrome Symptoms

Background and objectives: Premenstrual syndrome includes physical and mental symptoms occurring cyclically during the secretory phase. The present study aimed to specify the association between neuroticism and the severity of premenstrual syndrome symptoms. Method: This cross-sectional study was conducted on 223 students of Kerman University of Medical Sciences in 2019 November 17. Chi-square and Fisher’s exact tests were used to analyze the relationship between qualitative variables; stepwise logistic regression was employed to assess the factors affecting the syndrome symptoms, and Mann–Whitney U test was used to compare the scores of the Daily Record of Severity of Problems chart in two groups. Findings: 223 female students completed the first stage information. The mean score of the questionnaire was 151.72±100.11. Moreover, 77.6% of the students had the syndrome. The severity of symptoms was mild, moderate, severe, and highly severe in 53.6, 42, 3.6, and 0.7%, respectively. There was a significant relationship between premenstrual syndrome and neuroticism scores. Students with PMS had higher scores in all of the subscales (neuroticism including anxiety, stress, despair,..) (P<0.001). Conclusion: It seems that there is a relationship between neuroticism (anxiety, stress, despair) and the severity of PMS symptoms. Therefore, it is recommended that therapists and counselors consider these factors to treat and mitigate the severity of PMS symptoms.


Introduction
Premenstrual syndrome (PMS) is the most common syndrome in all healthy women at their fertility ages and includes periodic and recurrent symptoms such as physical, emotional, and mental symptoms. These symptoms occur in the luteal phase and resolve with the start of bleeding (2-3 days after menstruation) and repeat for 2-3 menstrual periods. (1-2-3-4-5) This syndrome is seen in all cultures and has varying effects on women's status, interpersonal relationships, relationship with children (such as conflict with children), and social interactions. This should be considered that the prevalence and severity of PMS are different in different cultures; moreover, there is no certain criterion for detecting this syndrome, and its cause is unknown. Most women experience PMS at least once in their lives, and it may include a wide range of clinical findings from mild, moderate to severe occurring in a relatively regular manner. (1,3,6,8-9-10) The prevalence of this syndrome varies based on factors such as exercise, diet, culture, and underlying diseases. In general, it can be stated that approximately half of the women around the world suffer from this syndrome (2,11).
According to the research done in different countries, the prevalence of PMS has been reported with different rates. For instance, the prevalence of this syndrome in the USA among women at their fertility ages was 20-40%, and the prevalence of premenstrual dysphoric disorder (PMDD, recurrent physical and mental symptoms in the luteal phase which is a severe form of PMS. Although PMS and PMDD are categorized separately, they belong to the same clinical classification with a common basic feature) was reported to be 3-8%. Moreover, the prevalence of this syndrome has been reported to be 20-50% in most western studies. Although no comprehensive study has been conducted on this syndrome in Iran, sporadic studies have reported a prevalence of 50-80% among students of Shiraz University of Medical Sciences (5,11,(13)(14). All age groups can be affected by PMS, yet the most common ages are reported to be 25 to 45 (2).
From social and cultural viewpoints and according to so researchers, PMS represents the negative attitudes and beliefs regarding the unpleasant experience of bleeding in menstruation. In fact, premenstrual experiences are quite varying and women do not experience similar changes; moreover, an individual's experience might vary in different months (6).
So far, 200 symptoms have been identified for PMS, and as mentioned before, they include physical, emotional, and mental symptoms. Most studies state that the highest prevalence (91.7%) is attributed to physical symptoms and these symptoms are dominant (2,13).
Depression: One of the major problems and symptoms of people with PMS is depression. Depression is a common mental disorder affecting work performance, interpersonal relationships, and so on. The prevalence of depression in women is twice that in men. These patients are at risk of psychiatric disorders, and therefore, determining efficient preventive treatment for them is essential (15,(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16).
Neuroticism: Neuroticism is a stable personality trait associated with anxiety, stress, frustration, emotional instability and insecurity, a tendency to evasion, … (11). The aforementioned symptoms of neuroticism will be briefly explained (based on previous research): -Anxiety: Anxiety is a feeling of uneasiness and fear. This feeling mostly occurs when people cannot predict or control the outcome. The results of this study indicate that women with higher AS levels experience more PMS symptoms compared with those with lower AS levels (17-18).
-Stress: According to the DSM-5, stress is a specific or non-specific response of the body to any kind of pressure imposed on it and it involves a part of each individual's life. Research shows that external stress is an effective factor in causing PMS. In fact, stress leads to an increase in cortisol levels, and since cortisol and progesterone fight over common cell receptors, cortisol causes disorders in progesterone activity and leads to an increase in estrogen activity which in turn chronically leads to the initiation or aggravation of PMS symptoms (4,13,19-20-21).
Frustration: Frustration is an emotional state that is a subcategory of the basic emotion of sadness. Frustration leads to depression, despair, loss of motivation, and suicidal thoughts (22).
As mentioned previously, PMS is unknown, yet numerous hypotheses have been proposed about it, such as an increase in estrogen, a decrease in progesterone, over-secretion of prolactin, idiopathic hypoglycemia, vitamin A, B1, and B6 deficiency, an increase in aldosterone, prostaglandins disorders, diet, obesity, and lifestyle (1,9).
Consequently, the present study was conducted aiming to determine the association between neuroticism and PMS symptoms among the students of Kerman University of Medical Sciences in 2019 November 17.

Method
This cross-sectional study aimed to assess the correlation between three variables related to neuroticism and PMS. The study population consisted of all female students of different levels living in dormitories of Kerman University of Medical Sciences in the second semester of 2020 September 22-2021 July 20. The correlation coefficient between PMS and neuroticism was r=0.18. With a confidence level of 99% and test power of 91%, the sample size was estimated to be 239 using the software. After the approval of the ethics committee and permission from the Razi School of Nursing and Obstetrics, the students were randomly selected from the dormitory rooms. Inclusion criteria: Female students of Kerman University of Medical Sciences, Razi School of Nursing and Obstetrics in the defined period (3 months, from April 9 to July 11). Independent variables included age (years), education (associate/bachelor/master/doctorate), first menstruation age (years), length of each menstruation period (less than 3 days, between 3 and 8 days, more than 8 days), the interval between two menstrual periods (less than 24 days, between 24-35 days, more than 35 days), regular menstruation (yes/no), physical illness (yes/no), mental illness (yes/no), smoking (yes/no), medication use, incident (no/ marriage/ death of a relative), exercise (never/ sometimes/ regularly). The response variable was the condition of PMS (having/not having). The Daily Record of Severity of Problems chart, in which 11 symptoms were analyzed, was used to record the daily information about PMS symptoms. Choices included no symptom, minor changes, mild changes, moderate changes, severe changes, and highly severe changes; these answers were coded from o to 5 and the severity was measured. The score of each symptom was calculated from a week before the period to 4 days after it and then divided by 11. The mean score was calculated in percentage and the severity of each symptom was obtained. For values less than 30%, the severity was considered mild. Moderate severity was attributed to 30%, or values greater than 30% and less than 50%. For values between 50 and 60%, the severity was considered severe and highly severe if it was more than 60%.
The Daily Record of Severity of Problems chart is a universal standard and considered a valid guideline for determining the severity of PMS and its validity has been confirmed in previous studies in Iran. The reliability of the Daily Record of Severity of Problems chart was confirmed by Mohebbi Dehnavi et al (2016); moreover, its validity is evaluated using Cronbach's alpha (internal consistency) with a reliability coefficient of 0.77.
The data were reported using descriptive and analytical statistics measures. In terms of descriptive statistics, frequency, percentage, mean, and standard deviation were reported. In terms of analytical statistics, Chi-square and Fisher's exact tests were used to analyze the relationship between qualitative variables, stepwise logistic regression was employed to assess the factors affecting the syndrome symptoms (having/not having), and Mann-Whitney U test was used to compare the scores of the Daily Record of Severity of Problems chart in two groups. The normality of the response variable was measured using the Kolmogorov-Smirnov test. SPSS 20 was used to analyze the data.
Findings 223 female students completed the first stage. The mean age of participants was 21.56 ± 1.94. Most students (78.9%). The descriptive information of the variables was reported. Approximately 89.3% of the students had 3-to-8-day menstrual periods, and 80.7% had a 24-35-day interval between their two menstrual periods. 64.1% had irregular menstruation, 2.7% had physical illnesses, 1.8% had mental illnesses, 4% smoked cigarettes, and 9.9% were using medication. Moreover, 2.7% had used contraceptive pills and 36.3% different types of vitamins. Additional information is presented in table 1.
The mean age at menarche was 13.33±1.51. Almost 95.4% had experienced menstruation before 15. In this study, 10 and 23 were the earliest and latest ages of the first menstruation. Approximately 77.6% reported having PMS symptoms a week before menstruation. Logistic regression was used for simultaneous analysis of the effect of all variables on PMS symptoms. Table 2 presents the variables affecting PMS symptoms based on logistic regression. According to this test, the length of each menstruation period was the only variable with a significant relationship with PMS. Students with 3-8 and more than 8 days length of menstruation period had respectively a 12 and 15-fold risk of suffering from PMS compared with those with length of menstruation period of less than 3 days.  Table 3 also presents the mean score of participants with and without PMS. In students with the syndrome, the tenth (lethargy, fatigue…), fifth (anger or irritability…), and second (anxiety, nervous pressure…) questions had the highest means, respectively. However, in students without the syndrome, the fifth (anger or irritability…), tenth (lethargy, fatigue…), and first (frustration and hopelessness…) questions had the highest means, respectively. As seen, the mean of the total score and all of the symptoms were higher in students with the syndrome compared to those without it. Statistically, these scores were compared using the Mann-Whitney U test, and the results indicated that the difference was significant in all symptoms and total scores.  Table 4 presents the analysis of the effect of the total score and the score of each question on PMS symptoms using logistic regression. In this case, PMS and scores were analyzed as the response and independent variables, respectively. As seen in the table above, there was a significant relationship between the total score of the Daily Record of Severity of Problems chart and PMS symptoms. One score increase in the total score led to a 2% increase in the incidence of PMS. Moreover, the relationship between each question and PMS was analyzed, and all questions had significant relationships with PMS. For one score increase in the first (frustration…), second (anxiety, nervous pressure…), third (difficulty in concentrating…), fourth (problems in daily interactions…), fifth (anger or irritability…), sixth (breast tenderness…), seventh (sleep disorder…), eighth (increased appetite…), ninth (sensitivity to rejection…), tenth (lethargy, fatigue…), and eleventh (less participation…) questions, there was a 19, 20, 23, 25, 13, 22, 19, 17, 18, 17, and 21% increase in the incidence of PMS.

Discussion
The results of the present study aimed to determine the relationship between neuroticism and the severity of Premenstrual Syndrome symptoms in university students indicated that the mean total score and score of all the symptoms were greater in students with the syndrome compared with those without it. In the present study, 77.6% of the students had the syndrome. In the participants, the severity of the symptoms was mild, moderate, severe, and highly severe in 53.6%, 42%, 3.6%, and 0.7% of the students respectively. In the study conducted by Nisar et al. in 2008, the prevalence of different severities of PMS was mild, moderate, and severe in 59.5%, 29.2%, and 11.2% of patients respectively. In the study conducted by Silva et al. (2008) in Turkey on women whose menarche occurred at the age of 11, the prevalence of mild, moderate, and severe syndrome was reported 80.8%, 12.4%, and 5.8% respectively. Statistics obtained from numerous sources and studies in different countries indicate obvious differences in the prevalence of different severities of PMS symptoms, which is in part due to cultural differences and negative attitudes toward menstruation and the resulting limitations on women's response to menstruation and related issues among different societies.
The present study was conducted on medical students, who have a less negative attitude toward menstruation due to their high levels of medical knowledge and consider menstruation as a physiological and natural phenomenon. Therefore, they accurately describe symptoms associated with menstruation, which can be the reason for the significant statistical differences between the present study and other studies on the prevalence of different severities of symptoms in people with the syndrome. With proper control of neuroticism (stress, anxiety, and frustration, etc.) in university students, the incidence and severity of PMS symptoms will decrease. Through decreasing brain beta-endorphins and increasing adrenal cortisol, stress causes mood symptoms in individuals, especially those with PMS. In the study conducted by Kathleen et al. (2006), there was a significant relationship between the stress score (one of the neuroticism symptoms) and the severity of PMS symptoms in such a way that higher levels of stress were associated with more severe symptoms in patients, which was in line with the results of the present study. Moreover, Shu Haicheng et al. (2013) considered stress as a factor in developing the syndrome and increasing the severity of its symptoms and reported a significant relationship between these two variables. However, in the study conducted by Lee et al. (2005) on undergraduate students in Hong Kong China, no statistically significant relationship was observed between stress and PMS. According to research, anxiety sensitivity (AS) may be an important mental factor in experiencing physical and mental symptoms during the menstrual period. The results of these studies prove that women with higher levels of AS experience more symptoms of menstruation compared with women with lower AS levels; Moreover, in the present study, a statistically significant relationship was observed between these two variables. In the study conducted by Lustic et al., the most prevalent symptoms of PMS were irritability, anxiety, anger, and depression; similarly, in the present study anger and depression were also prevalent symptoms. Furthermore, this study indicated that appetite changes were observed in 17% of those with PMS, which was statically significant.
Compared with the studies conducted by Gman on PMS in 1995, it was proved that food high in carbohydrates (such as soft drinks) that increase tryptophan significantly reduce depression, anger, and restlessness in 90 to 180 minutes after ingestion. In the present study, these changes in appetite also reduced the symptoms. One of the causes of the relationship between the severity of PMS symptoms and neuroticism in the present study might be the fact that the study was conducted on medical students that are fully familiar with the medical discourse; therefore, they accurately reviewed their symptoms during these stages without overlooking any particular behavior. Moreover, the results of the present study are partly affected by the presence of specific issues in the students' lives that are full of various anxieties and stresses such as economic problems, specific conditions of students' residence, distance from family, incompatibility, and The present study had some limitations and considering them can lead to a better understanding of PMS and neuroticism in university students. For instance, selfreport was the basis for assessing neuroticism in samples; as a result, the responses may have been influenced by cultural and social factors in some cases. Although an attempt was made to control this limitation to some extent by further explaining the objectives of the study and establishing more communication, it was not possible to fully control this limitation.

Conclusion
People with lower levels of neuroticism have less severe PMS symptoms. Therefore, it is recommended to consider neuroticism (stress, anxiety, frustration, etc.) and its impact on different severities of the symptoms in people with PMS during counseling and treatment.