Depression
Depending on the outcome measure that was used, depressive symptoms occurred in 10-86% of patients with endometriosis. Symptoms were reported to be mild in 13-68% and moderate to severe in 2-64% of patients. In comparison, depressive symptoms occurred in 7-19% of healthy controls in the included studies. Chen et al (2016) reported an increased risk of developing a major depression (HR: 1.56, 95% CI:1.24-1.97) and any depressive disorder (HR: 1.44, 95% CI: 1.25-1.65) for women with endometriosis compared with healthy controls [31].
Most case-control studies, reported that symptoms of depression occurred significantly more often in endometriosis patients compared with healthy controls [28,30-32,35,39,43,46,51,56,62,66,68] but not compared with CPP patients without endometriosis [29,43,48,53,54,56,57,60,62,67]. On the contrary, four studies did not find a higher depression rate in endometriosis patients compared with healthy controls [38,44,57,71]. Two studies found no difference in depression symptoms in pain-free endometriosis patients compared with healthy controls [28, 35]. A study by Stratton et al (2015) found a higher rate for depression in CPP patients compared with endometriosis patients [68].
Figure 2a shows pooled data including 11 studies comparing 513 endometriosis patients with 600 healthy controls. Meta-analysis reveals a significant higher symptom score for depression in patients with endometriosis (SMD 0.71 (95% CI 0.36 – 1.06). Figure 2b shows pooled data including 11 studies comparing 284 endometriosis patients with 407 CPP patients without endometriosis. Meta-analysis shows no significant difference in depression scores between the two groups (SMD -0.01 (95% CI -0.17 – 0.15)). The mean scores and SD of age and results on validated outcome questionnaires per study are shown in Table 1 and 2.
Anxiety Depending on the outcome measurement, anxiety occurred in 10-79% of patients with endometriosis. Symptoms of anxiety were reported mild in 22-79% and moderate/severe in 23-64% of patients. In comparison, anxiety occurred in 6-14% of healthy controls in the studies included. Chen et al (2016) reported an increased risk for women with endometriosis of developing anxiety disorders (HR: 1.44, 95% CI: 1.22-1.70) compared with healthy controls [31].
Twelve studies reported higher anxiety scores (including state, trait and phobic anxiety) in endometriosis patients compared with healthy controls [28,31,32,35,39,43,44,46,51,56,66,68]. In nine studies no differences in anxiety scores were found between endometriosis patients and CPP patients [29,43,44,54,56,57,60,62,67]. However, four studies did not report any difference between endometriosis patients and healthy controls concerning anxiety scores [30,38,57,62]. Quiñones et al (2015) reported higher trait anxiety in endometriosis patients compared with healthy controls, but no difference in state anxiety. Two studies reported a controversial difference in anxiety scores between endometriosis patients and CPP patients without endometriosis [48,68].
Figure 2c shows pooled data including 12 studies comparing 544 endometriosis patients with 636 healthy controls. Meta-analysis shows significant higher anxiety scores in patients with endometriosis (SMD 0.60 (95% CI 0.35-0.84). Figure 2d shows pooled data including 11 studies comparing 284 endometriosis patients with 407 CPP patients without endometriosis. Meta-analysis reveals no significant difference in anxiety scores between these groups (SMD -0.02 (95%CI -0.22 – 0.18). In this meta-analysis the state anxiety score (but not the trait anxiety score) is used when the STAI questionnaire was assessed.