Muscle dysmorphia (MD) symptoms are robustly associated with suicidal thoughts/behaviors. Risk factors for suicidal ideation, such as perceived burdensomeness and thwarted belongingness, may help explain the relationship between MD symptoms and suicidal ideation. The current study extended past cross-sectional research by testing if perceived burdensomeness and/or thwarted belongingness mediated longitudinal relationships between MD symptoms and suicidal ideation. Two hundred and sixty-nine U.S. men recruited from Prolific completed self-report measures at three timepoints separated by one month each. Analyses used an adapted version of a longitudinal three-wave mediation model to test study hypotheses. Perceived burdensomeness mediated longitudinal relationships between MD symptoms and suicidal ideation. Thwarted belongingness did not show significant relationships with MD symptoms or suicidal ideation. Results extend past research by demonstrating that perceived burdensomeness may be a mechanism underlying longitudinal relationships between MD symptoms and suicidal ideation while establishing temporal ordering. Clinicians may consider targeting perceived burdensomeness in cases of comorbid MD/suicidality by using techniques that promote interpersonal effectiveness.

肌肉畸形（MD）症状与自杀想法/行为密切相关。自杀意念的危险因素，例如感知到的负担和归属感受挫，可能有助于解释MD症状与自杀意念之间的关系。目前的研究扩展了过去的横断面研究，测试了感知到的负担和/或受挫的归属感是否介导了MD症状和自杀意念之间的纵向关系。从 Prolific 招募的 269 名美国男性在三个时间点完成了自我报告措施，每个时间点相隔一个月。分析使用纵向三波中介模型的改编版本来检验研究假设。感知的负担介导MD症状和自杀意念之间的纵向关系。归属感受挫与MD症状或自杀意念没有显着关系。结果表明，在建立时间顺序时，感知到的负担可能是MD症状与自杀意念之间纵向关系的潜在机制，从而扩展了过去的研究。临床医生可以考虑通过使用促进人际关系有效性的技术来针对共病MD/自杀病例中的感知负担。