The mediating role of sexual dysfunction knowledge in the association between sexual function and depression: a large-scale national cross-sectional study in reproductive-aged population

BACKGROUND: Sexual dysfunction (SD) and depression are prevalent issues that significantly affect both physical and mental health. AIM: This study aimed to explore the association between sexual function (SF) and depression in reproductive-aged population and further examine the mediating role of knowledge regarding the effect of sexual dysfunction on fertility (KSDF). METHODS: This study enrolled a total of 10 761 participants aged 20-40 from 31 regions, including 5259 males and 5502 females, with a median age of 29.0 years. Basic demographic data were collected initially, followed by clinical data acquisition. OUTCOMES: The International Index of Erectile Function 5 (IIEF5), the Premature Ejaculation Diagnostic Tool (PEDT), the Female Sexual Function Index-19 (FSFI-19), the Patient Health Questionnaire-9, and the Disease Knowledge Questionnaire. RESULTS: The study revealed a significant bidirectional association between SF and depression among the population. Specifically, poorer SF was correlated with higher severity of depressive (IIEF5 [β = -0.155, P < .001], PEDT [β = 0.311, P < .001], and FSFI-19 [β = -0.059, P < .001]). Conversely, higher severity of depressive was associated with poorer SF (IIEF5 [β = -0.202, P < .001], PEDT [β = 0.249, P < .001], and FSFI-19 [β = -0.191, P < 0.001]). Furthermore, in males, the KSDF mediated the bidirectional associations between SF and depression. Specifically, the mediating proportions were as follows: KSDF mediated 3.00% of the association between IIEF5 and depression, and 2.20% of the association between PEDT and depression; similarly, for the association between depression and SF, KSDF mediated 2.50% of the association between depression and IIEF5 and 2.20% between depression and PEDT. However, no such mediation was observed in females. CLINICAL IMPLICATIONS: This provides new insights for the clinical management of these issues in the male reproductive-aged population. STRENGTHS AND LIMITATIONS: These findings suggest that enhancing this knowledge could interrupt bidirectional association between impaired SF and depression in this demographic, potentially alleviating both conditions without requiring additional interventions. However, cross-sectional study design does not allow us to draw corresponding causal conclusions. CONCLUSION: The current study further demonstrated a significant bidirectional association between SF and depression among the reproductive-aged population, and importantly, the KSDF was found to mediate this association in males.