Study finds connection between depression severity and risk of endometriosis

By Pooja Toshniwal PahariaReviewed by Lily Ramsey, LLMNov 2 2023

In a recent study published in Scientific Reports, researchers investigated whether depression was associated with endometriosis.

Study: Association between depression and endometriosis using data from NHANES 2005–2006. Image Credit: AfricaStudio/Shutterstock.com

Background

Endometriosis is a complicated chronic inflammatory disorder marked by endometrial tissue (stroma and glands) developing beyond the uterus.

Despite multiple studies, the cause of this benign gynecological illness remains unknown. Endometriosis manifests clinically as pelvic discomfort, infertility, and menstrual cramps, inflicting significant social and financial consequences on people, families, and society.

Although surgical and medication treatments are now available for the treatment of endometriosis, they are inadequate due to the high recurrence rate. More research is needed to find better ways to prevent and manage endometriosis.

Depression has been linked to gynecological concerns such as sexual dysfunction and infertility in previous studies. However, studies on the relationship between depression prevalence and self-documented endometriosis are scarce, warranting further research.

About the study

In the present cross-sectional study, researchers investigated the influence of depression on the prevalence of self-documented endometriosis.

The team analyzed the 2005 to 2006 National Health and Nutrition Examination Survey (NHANES) data obtained from 100 individuals with self-reported endometriosis and 1,295 individuals without self-reported endometriosis. Only females 20 to 54 years of age were included. 

The Patient Health Questionnaire 9 (PHQ9) assessed depression severity. PHQ9 scores ≥10 indicated depression, which was further categorized as moderate (PHQ scores in the 10 to 14 range) and severe (PHQ9 scores ≥15).

Interviews were conducted at participants’ homes, followed by laboratory investigations and physical examinations at mobile examination centers (MECs). Self-documented endometriosis was ascertained using the rhq360 questionnaires administered at the MECs. 

Pregnancy history and age at menarche were included as disease-associated covariates using the rhq010 and rhq031 questionnaires.

Multivariable logistic regression modeling was performed to calculate the odds ratios (ORs). In addition, subgroup analyses were performed to assess heterogeneity.

Males and individuals with inadequate data concerning endometriosis, covariates [such as age, body mass index (BMI), marital status, race, poverty, level of education, poverty income ratio (PIR), alcohol intake, and smoking status], and PHQ9 were excluded.

The individuals were stratified by age as 20- to 29-year-olds, 30- to 40-year-olds, and 41- to 54-year-olds. Marital status subgroups included single, married, separated, or divorced. Educational attainment was documented as below high school, high school, and college or above. Income levels were classified as high (PIR equivalent to or above 3.0), medium (PIR equal to or above 1.35 but below 3.00), and low (PIR below 1.35).

Based on their smoking status, individuals were classified as never, current, or former smokers. Alcohol intake subgroups were non-consumers, mild consumers, moderate consumers, heavy consumers, and former consumers.

Based on BMI values (in kilograms per square meter), individuals were categorized as underweight (body mass index values below 18.5), normal (body mass index values ranging between 18.5 and 24.9), overweight (body mass index values ranging between 25 and 29.9 ), or obese (body mass index values equal to or above 30).

Results

The prevalence of endometriosis was 7.2%. A significant positive association was found between the PHQ9 scores and endometriosis (adjusted OR, 1.1).

Compared to individuals without depression, those with moderate depression were more likely to develop endometriosis (adjusted OR, 2.5). However, severe depression was not significantly linked to endometriosis.

Compared to individuals aged 20 to 29 years, those aged 41 to 54 years were positively linked with the prevalence of endometriosis (OR, 2.9). Compared to white individuals of non-Hispanic ethnicity, Mexican Americans were negatively associated with the development of endometriosis (OR, 0.2). 

White individuals were more likely to develop endometriosis compared to non-white individuals. However, due to accessibility to good medical care services, white individuals showed a better prognosis with lower mortality compared to other races.

Further, non-significant relationships were observed between medium and high-income categories and endometriosis. Individuals aged 41 to 54 years had a higher prevalence of endometriosis than those aged 20 to 29 years, which could be explained by the chronic-continuous-type morbidity patterns consistent with endometriosis.

Conclusions

The study findings showed that PHQ9 scores were strongly and positively correlated with endometriosis prevalence. 

Moderate depression was significantly and positively correlated with self-documented endometriosis prevalence. Race and age were identified factors that could independently increase the risk of endometriosis.

The findings indicate the need to monitor reproductive-age females for depressive symptoms and could inform endometriosis management.

Further research, including large-scale prospective cohort studies, is required to elucidate causal associations between the presence of depression and endometriosis and improve the generalizability of the study findings.