The Relationship Between Negative Life Events and Anhedonia among Patients with Major Depressive Disorder: Chain Mediation of Insomnia and Dysfunctional Attitudes

Anhedonia is a common problem among patients with depression. Negative life events have been associated with the severity of anhedonia, potentially through insomnia and dysfunctional attitudes. This study aimed to investigate whether insomnia and dysfunctional attitudes mediate the relationship between negative life events and anhedonia among patients with major depressive disorder (MDD). This study involved 979 participants with MDD in a public hospital from December 2019 to December 2021. The Life Events Scale (LES), Insomnia Severity Index (ISI), Dysfunctional Attitude Scale (DAS), Snaith-Hamilton Pleasure Scale (SHAPS) were used to assess participants’ negative life events, insomnia, dysfunctional attitudes and anhedonia. Five hundred and twenty-three participants reported symptoms of anhedonia (SHAPS > 33, 53.4