Association Between Sleep Disorders And Anhedonia Symptoms In Adolescents With Depression And Their EEG Characteristics

Objective:Major depressive disorder(MDD)is one of the most common health concerns worldwide.Adolescent period is the first stage of most mental disorders,during which the prevalence of MDD in adolescents significantly increases.The lifetime prevalence of MDD among adolescents aged 15 to 18 is between 11 and 14 percent,and about 20 percent of adolescents suffer from MDD by the age of 18.Adolescent MDD tends to cause heavy family burden and the impairment of social function,and also significantly increases the risk of suicide.Anhedonia,which means that an individual reduces the ability to experience pleasure or loses interests towards stimuli previously thought to be a reward,is core symptom of MDD.Anhedonia is particularly prominent in adolescents with MDD,predicting the high risk of suicidal or self-injury behavior and low response to antidepressant medications.However,the factors associated with anhedonia symptoms still need to be further explored.The sufficient sleep quality and quantity is essential for maintaining healthy cognitive and emotional function.Some researches suggested that up to 90% of people with depression have sleep disorders,and at least two-thirds of adolescents with depression have severe sleep disturbances.However,the relationship between sleep disturbance and anhedonia symptoms in adolescents with MDD remains unclear.In addition,the diagnosis of sleep disorders is mostly based on sleep diary,scale evaluation and polysomnography monitoring,which has their own advantages and disadvantages.With the widespread application of portable EEG monitoring,new directions have been provided for exploring EEG markers of sleep disorders.This study aims to explore the relationship between sleep disorder and anhedonia in adolescents with depression,discover potential EEG-related indicators,and provide a new direction for the early diagnosis and treatment of adolescent depression.Method:This is a cross-sectional study,and 200 adolescents with MDD met the DSM-5diagnostic criteria were included.The sample size set in current study was based on the results of the pilot and the analysis of the primary outcome indicators.The degree of depression,anxiety,anhedonia,sleep quality,social functioning,stress and quality of life of children and adolescents was assessed by Hamilton Depression Scale(HAMD),Hamilton Anxiety Scale(HAMA),Snath Hamilton Pleasure Scale(SHAPS),Pittsburgh Sleep Quality Index(PSQI),Sheehan Disability Scale(SDS),Stressor Scale for Middle School Students(SSMSS),and Quality of Life Scale for Children and Adolescents(QLSCA).After all enrolled patients completed the relevant scales,researchers used Pearlcare YY-106 portable EEG monitoring device(Zhejiang Pearlcare Medical Technology Co.,Ltd.)to collect prefrontal EEG signals with eyes closed for 20 minutes in a quiet environment.Patients were divided into two groups: "sleep disturbance(PSQI>7)" and "no sleep disturbance(PSQI≤7)" according to whether PSQI score was more than 7.Based on the different type of variables,a two-sample t-test or chi-square test was used to compare the baseline data between two groups.Correlation analysis of clinical variables using Pearson correlation analysis,univariate analysis and multiple linear regression model according to data type.MATLAB software was used to extract EEG data and analyze it further.Outcomes:1.The prevalence of sleep disorders in adolescents with MDD is 85.5%.Compared with depressed adolescents without sleep disorders,adolescents with sleep disorders get higher SHAPS scores,a higher proportion of patients with severe and extremely severe social skills/hobbies and family life on the SDS,and lower QLCSA scores.These results indicate that patients with sleep disorders had more severe symptoms of anhedonia,greater impact on social skills,hobbies and family life,and lower quality of life(P<0.05).2.The results of univariate analysis showed that the anhedonia symptom score was significantly correlated with sleep disturbance,anxiety,depression,stress events and quality of life(P<0.05).3.A multiple regression model was established to analyze the relationship between anhedonia symptoms and sleep disorders,and the results showed that compared with depressed adolescents without sleep disorders,the SHAPS score of patients with sleep disorders was 5.21 points higher in the model without any confounding factors and the difference was statistically significant(P<0.005).The SHAPS score was 5.34 points higher(P<0.05)after age and gender,4.58 points(P<0.05)higher after anxiety score,and then 3.67 points higher after depression score,and 2.91 points(P<0.05)higher after stressful event score,the results were statistically significant.4.The results of univariate analysis showed that the scores of life quality were significantly correlated with age,sex,presence or absence of sleep disturbance,anxiety,depression,and stress events(P<0.05).A multiple regression model was established to analyze the relationship between quality of life and sleep disorders,and the results showed that the QLSCA score of patients with sleep disorders was 10.9 points lower and statistically significant(P<0.001)compared with adolescents with depression without sleep disorders in the model without any confounding factors.The QLSCA score was 11.2 points lower(P<0.001)after age and sex,followed by an 8.96 point lower QLSCA score(P<0.001)after anxiety score,followed by a depression score of8.04 points lower(P<0.001),and a 6.14 lower QLSCA score after stressful events(P<0.001),the results were statistically significant.5.The results of Sheehan Disability Scale suggest that although there is no difference in the degree of influence among adolescents with or without sleep disorders in terms of academic disorders,it cannot be ignored that 60% of all patients have severe to extremely severe academic impacts.In addition,more depressed adolescents with sleep disorders were severely affected in terms of social skills and family responsibilities,and the difference between the two groups was statistically obvious(P<0.05).6.The results of the EEG related indicators suggest that the two-sample t-test of EEG alpha power in adolescents with or without sleep disorders found no significant difference between the two groups(P>0.05).But there is a difference in the theta and gamma power between the two groups.Depressed adolescents with sleep disorders had lower EEG theta power and higher gamma power(P<0.05).Conclusion:Among adolescents with MDD,patients with sleep disturbances had more severe symptoms of anhedonia,lower quality of life,and higher proportion of severe impact on social skills and family responsibilities than those without sleep disorders.In the process of EEG data analysis,it was found that the alpha power of adolescents with or without sleep disorders was not significantly different,but in adolescents with sleep disorders,the EEG theta power was lower and gamma power was higher.