The Relationship Between Sleep Quality And Suicidal Ideation: The Longitudinal Mediating Role Of Negative Emotions And Its Neural Mechanis

Suicide can occur at all stages of the lifespan,and has become the fourth leading cause of death in the global 15-29 age group.College students are in a unique developmental stage as they transition from adolescence to early adulthood.They face numerous opportunities and challenges in social,academic and employment settings,and are highly vulnerable to various psychological problems,including extreme behaviors such as self-injury and suicide.Suicidal ideation is often considered as the first step on the pathway to suicide and is one of the most potent predictors of future suicidal behavior.The incidence of suicidal ideation among college students in China ranges from 3.90% to 17.60%.Although many studies have investigated the influencing factors for suicidal ideation,there is still a lack of effective targets for clinical intervention.Poor sleep quality and negative emotion are both strongly associated with an increased risk of suicide in individuals,and they are easily detectable and modifiable.Therefore,this study investigates the impact of sleep quality and negative emotion on suicidal ideation among college students based on the escape theory of suicide,the stress vulnerability model,and the three-step theory of suicide.Additionally,this study uses resting-state functional magnetic resonance imaging to investigate the neural mechanism by which sleep quality affects suicidal ideation in college students.This study consisted of three sub-studies.In study 1,Pittsburgh Sleep Quality Index,Positive & Negative Affect Scale and Beck Scale for Suicide Ideation Chinese Version were used to measure sleep quality,negative emotion,and suicidal ideation among 557 college students.A mediation model was conducted to explore the relationships among them.In study 2,a longitudinal method was adopted,and questionnaires were used to evaluate the main factors among 324 college students at two time points.Cross-lagged and inter-temporal mediation models were constructed to test the relationship between T1 sleep quality and T2 suicidal ideation,as well as the mediating role of negative emotion in the relationship.In study 3,resting-state functional magnetic resonance imaging was used to scan the brains of 70 college students.The association between suicidal ideation and the amplitude of low-frequency fluctuations(ALFF)was explored,and a mediation model of sleep quality-brain-suicidal ideation was established.Based on the three sub-studies,the main results were as follow:(1)Sleep quality positively predicted suicidal ideation through the mediating effect of negative emotion;(2)T1 sleep quality significantly and positively predicted the development of T2 suicidal ideation through the mediating effect of T2 negative emotion;(3)Suicidal ideation was positively related to the regional ALFF in the frontal＿Inf＿Tri＿L and PCL＿L.Critically,mediation analysis further revealed that the ALFF of the frontal＿Inf＿Tri＿L plays a mediating role in the association between sleep quality and suicidal ideation.In summary,this study revealed that sleep quality is an effective short-term risk factor for suicidal ideation in college students.The effects of sleep quality on suicidal ideation may involve both psychological and neurobiological pathways.These results provided scientific basis for the early screening of suicidal risk in college students and the development of related prevention and control measures.