--- title: Which established risk factors genetically cause premenstrual disorder? description: Genetic analysis suggests three factors cause premenstrual disorder: earlier age at first period, higher BMI, and smoking. However, when tested in a smaller g url: https://niyora.com/research/papers/mendelian-randomization-of-risk-factors-for-premenstrual-disorders-2026/ --- - [Niyora](https://niyora.com/) - [Research](https://niyora.com/research/) - [Library](https://niyora.com/research/library/) - Which established risk factors genetically cause premenstrual disorder? Cohort study, 2026 # Which established risk factors genetically cause premenstrual disorder? Genetic analysis suggests three factors cause premenstrual disorder: earlier age at first period, higher BMI, and smoking. However, when tested in a smaller group, results were not consistent, so more research is needed to be sure. Moderate study design Genetic data from 72,297 women in large genetic studies and 5,674-5,937 women in LifeGene cohort in Sweden ## What they did Researchers used Mendelian randomization (a genetic method to test if something causes a disease) to analyze 8 known risk factors for premenstrual disorder. They used genetic data from large studies (GWAS) with 72,297 participants for premenstrual disorder, then validated findings in a smaller cohort (LifeGene, 5,674-5,937 women). ## What they found In the larger genetic analysis, smoking (odds ratio 1.25), earlier age at first period (odds ratio 0.94 per year), and higher BMI (odds ratio 1.19 per kg/m²) showed causal association with premenstrual disorder. No causal association was found for anemia, childhood abuse, asthma, diabetes, or endometriosis. When validated in the smaller study, results for BMI and menarche were directionally consistent but not statistically significant, and smoking showed no association. ## What it means for you Genetic evidence suggests smoking, BMI, and early puberty may cause premenstrual disorder, but the validation study did not fully confirm these findings. We need larger, better-powered studies to confirm which factors truly cause the condition. 72,297 Total premenstrual disorder participants in GWAS 1.25 Odds ratio for smoking 1.19 Odds ratio per kg/m² for BMI ## About the study Original title Mendelian randomization of risk factors for premenstrual disorders Authors Yang Y, Tang B, Hysaj E et al. Journal Npj mental health research Year 2026 Study design Cohort study Participants 5,674 What was tested Eight established risk factors tested for causal association with premenstrual disorder Open access Yes Read the paper [doi.org/10.1038/s44184-026-00231-4](https://doi.org/10.1038/s44184-026-00231-4) Original abstract The causal role of established risk factors for premenstrual disorders (PMDs) remains unclear. We used Mendelian randomization (MR) to assess causality for eight known-risk factors identified through a literature review. Summary statistics for these risk factors were from genome-wide association studies (GWAS) with sample size ranging from 129,017 to 1.2 million, and for PMDs from a GWAS of 72,297 participants. Findings were validated using one-sample MR in LifeGene cohort (n = 5674-5937). In two-sample MR, genetic liability to smoking initiation (OR = 1.25 (1.10-1.43)), earlier menarche (OR = 0.94 (0.89-0.98) per year), and higher BMI (OR = 1.19 (1.05-1.34) per kg/m 2 ) were associated with PMD risk. No causal association was indicated for anemia, childhood abuse, childhood asthma, diabetes, and endometriosis. In one-sample MR, point estimates for BMI (OR = 1.10 (0.88-1.38) per kg/m²) and earlier menarche (OR = 0.98 (0.83-1.15) per year) were directionally consistent with the two-sample MR findings, but the confidence intervals included null effects. However, a null association was observed for smoking (OR = 0.94 (0.77-1.16)). The two-sample MR supports causal role of earlier menarche, higher BMI, and smoking in risk of PMDs. The lack of replication in one-sample MR highlights the need for triangulating evidence from future well-powered and methodologically comparable studies to strengthen these findings. Reproduced under CC-BY. ## Topics [Premenstrual syndrome (PMS)](https://niyora.com/research/topics/condition-pms/)[Alcohol, smoking and substance use](https://niyora.com/research/topics/comorbidity-substance-use/)[Endometriosis](https://niyora.com/research/topics/comorbidity-endometriosis/)[Adolescents and young people](https://niyora.com/research/topics/life-area-adolescents/) Research tells you what helps on average. Niyora helps on the day it hits. Calm down, see it another way, and decide what to say, with a PMS and PMDD app built by a doctor. ## Related studies Cohort study, 2026 Do early-life exposures like antibiotics or breastfeeding affect PMS risk? Systematic review, 2025 Does alcohol use affect menstrual health in teenage girls? Cohort study, 2014 How common are PMS and dysmenorrhea in young women and do they change over time? Survey study, 2025 Are premenstrual symptoms linked to depression in teenage girls? Survey study, 2024 Is physical activity linked to PMS symptoms? Survey study, 2024 What factors are linked to PMS in school-age girls? Ask AI about this page Copy prompt ChatGPT ↗ Claude ↗ Perplexity ↗ Google AI Mode ↗ Grok ↗