Associations Of Non-Suicidal Self-Injury With Suicidal Ideation And Attempted Suicide Among Middle School Students And Gender Differences

ObjectiveThe aims at this study were to describe the distribution characteristics of non-suicidal self-injury(NSSI),suicidal ideation and attempted suicide among middle school students,and also to determine the relationships between NSSI frequency,methods and functions with suicidal ideation and attempted suicide and the gender differences.MethodsA total of 22 740 middle school students were selected for questionnaire survey from 42 schools in 6 cities including Shenyang,Shaoxing,Guiyang,Zhengzhou,Nanchang and Shenzhen of China by stratified cluster sampling method.Adolescent Non-suicidal Self-injury Assessment Questionnaire was used to obtain the occurrence and function of NSSI in last year.Items of suicidal ideation and attempted suicide from Youth Risk Behavior Surveillance System in America were used to get information about seriously considered suicide or suicidal behavior in recent year.Chi Square tests were used to compare the differences in the rates of NSSI,suicidal ideation and attempted suicide with different demographic characteristics among middle school students.After adjusting the grade,urban economic level,whether in boarding school on weekdays,residency,single child status,parents’ education level,family economicconditions,intimate partner numbers and mobile phone use dependency,multivariable Logistic regression models were used to analyze the relationships between frequency,methods and functions of NSSI with suicidal ideation and attempted suicide,and the relative risk ratio was calculated to compare the gender differences.ResultsThe prevalence of NSSI,suicidal ideation and attempted suicide were 7.9%(1729/21 831),17.7%(3867/21 831)and 5.0%(1083/21 831),respectively.The suicidal ideation and attempted suicide rates increased as NSSI frequency and severity increased(P < 0.001).Once demographic controls were introduced,NSSI frequency and severity of methods were positively correlated with suicidal ideation and attempted suicide(P <0.001).NSSI functions(excluding “to control oneself and calm oneself down”)were independent risk factor of suicidal ideation and attempted suicide(P < 0.01).Using NSSI to get even with others(OR = 2.59,95%CI: 1.58 ～ 4.24)and to hurt oneself and can’t stop(OR = 2.49,95%CI: 1.75 ～ 3.53)were most significantly associated with suicidal ideation.“I had a desire to hurt myself and can’t stop”(OR = 4.05,95%CI: 2.91～ 5.64)and “to attract attention”(OR = 3.31,95%CI: 2.24 ～ 4.89)showed the strongest relation to suicide attempts.With 5 ～ 10 NSSI,the risk of suicidal ideation and attempted suicide in female students was higher than that in male students [ROR(95%CI)= 1.54(1.19 ～ 1.99),1.81(1.26 ～ 2.60)].With NSSI ≥ 11 times,female students had a higher attempted suicide risk than male students(ROR = 1.62,95%CI: 1.04 ～ 2.53).NSSI without obvious tissue damages,the correlation between NSSI and suicide attempt in female students was stronger than that in male students(ROR = 1.69,95%CI: 1.10 ～ 2.59).Low frequency with obvious tissue damages group,girls have a higher risk of suicidal ideation than boys [ROR(95%CI)= 1.72(1.06 ～ 2.80),P = 0.029],low frequency without obvioustissue damage group,girls have a higher risk of attempted suicide than boys [ROR(95%CI)= 1.78(1.08 ～ 2.93),P = 0.024].In terms of “self-negative reinforcement”(ROR = 1.76,95%CI: 1.09 ～ 2.86),“emotional expression” dimension(ROR = 2.27,95%CI: 1.47 ～ 3.50)and “cope with sadness and disappointment”(ROR = 1.74,95%CI:1.13 ～ 2.66),NSSI was more strongly associated with suicidal ideation in females than in males.“I have a desire to hurt myself and I can’t stop” was found to be more associated with suicide attempts in boys than girls(ROR = 0.47,95%CI: 0.24 ～ 0.93).ConclusionsThese findings suggested that NSSI increased the risk of suicidal ideation and attempted suicide in middle school students.Overall,the relationship between NSSI and suicidal psychological behavior was stronger in girls than boys.Understanding different types of NSSI and formulating interventions by gender may effectively prevent the occurrence of suicidal psychological behaviors.