Prevalence and risk factors for non-suicidal self-injury among patients with depression or bipolar disorder in China

Backgrounds Non-suicidal self-injury is a serious health problem among patients with depression or bipolar disorder. However, few studies within the Chinese context have investigated the prevalence of NSSI and its risk factors in above populations. The purpose of this study was to investigate the prevalence of non-suicidal self-injury and its risk factors in patients with depression or bipolar disorder in China. Methods The final sample comprised of 394 inpatients(M-age = 29.71; SDage = 11.95) with depression or bipolar disorder from two psychiatric hospitals in Beijing, China. A General Demographic Data Form, the Non-suicidal Self-injury Questionnaire(NSSI-Q), Impulsivity Item and the Adverse Childhood Experiences-International Questionnaire(ACE-IQ) were completed by all patients. Results Of the 394 patients examined, 245(62.2%) of this sample reported NSSI in past year. Of the 245 patients with NSSI, 135(55.1%) were diagnosed with depression and 110(44.9%) were diagnosed with bipolar disorder. The most common methods of NSSI for female was "pinching"(23.1%) and "scratching"(22.8%), while for male it was "hiting hard objects"(12.7%). By multivariate regression analysis, young age, unemployment, a higher monthly family income, single, impulsivity, long duration of illness and ACEs were risk factors for NSSI in patients with depression and bipolar disorder(P<0.05). Conclusions Our study points to the fact that there was an unfortunate message about the prevalence of NSSI among patients with depression or bipolar disorder in China. It is necessary not only to raise the awareness of NSSI in families and society, but also to formulate targeted assessment and intervention. Moreover, future research should not only focus on individuals being hospitalized, but should be representative of individuals treated at home or in the community because there are no national statistics on NSSI among such patients in China.