Background: Endometriosis stage is not directly related to the burden of symptoms, and recurrence of symptoms occurs frequently. It is suggested that symptoms are associated with psychological distress, as in depression and anxiety disorders. Our aim was to explore the strength of the associations between endometriosis and depression or anxiety and to review correlating factors. Materials and Methods: A literature search was carried out using the electronic databases Embase, PubMed, Web-of-science, and PsycINFO. Search terms related to depression, anxiety, and endometriosis were combined resulting in 1,837 records. Articles were included when describing an association between patients with endometriosis and symptoms of depression or anxiety assessed by validated tools, structured psychiatric interviews, or a documented diagnosis. With 47 articles a systematic qualitative review was performed. Seventeen studies were eligible for meta-analysis. Results: Endometriosis patients experienced significantly more symptoms of depression (standardized mean difference [SMD] of 0.71 (95% confidence interval [CI] 0.36-1.06)) and anxiety (SMD 0.60 (95% CI 0.35-0.84)) compared with healthy controls, but no differences were found comparing endometriosis patients with other chronic pelvic pain patients (SMD -0.01 [95% CI -0.17 to 0.15] for depression and SMD -0.02 [95% CI -0.22 to 0.18] for anxiety). Besides the effect of pain, other correlating factors included age, quality of life, quality of sleep, fatigue, sexual function, gastrointestinal symptoms, comorbidity, self-esteem, emotional self-efficacy, coping style, social adjustment, pain imagery, and pain sensitization. Conclusion: This systematic review supports the assumption that symptoms of depression and anxiety occur frequently in endometriosis patients and are related to chronic pain. Correlating factors should further be investigated.
Keywords: anxiety; depression; endometriosis; pain; psychosomatic symptoms.