Suicide attempt rate and the risk factors in young, first-episode and drug-naïve Chinese Han patients with major depressive disorder

Background In recent years, the rates of suicide among young people have been increasing, and major depressive disorder (MDD) is regarded to be its main cause. Many factors such as thyroid dysfunction and metabolic abnormalities are thought to mediate this process, but the conclusions are inconsistent. This study investigated the rate of suicide attempts and associated risk factors among young, first-episode and drug-naïve Chinese Han patients with MDD. Methods A total of 917 patients with MDD (aged 18 ~ 35 years) were recruited. Demographic and clinical data were collected and thyroid function, fasting blood glucose and lipid profiles were measured. The Hamilton Depression Rating Scale-17 items (HAMD-17), Hamilton Anxiety Rating Scale (HAMA), positive symptom subscale of Positive and Negative Syndrome Scale (PANSS) and clinical global impression of severity scale (CGI-S) were adopted to assess depression, anxiety, psychotic symptoms and disease severity respectively. Results The rate of suicide attempts was 19.5% in young MDD patients. There were significant differences in age ( p = 0.003), education level ( p = 0.001), age of onset ( p = 0.004) and disease duration ( p = 0.001) between patients with and without suicide attempts. Compared with patients without suicide attempts, patients with suicide attempts had significantly higher scores on the HAMD-17, HAMA, PANSS positive symptom subscale and CGI-S (all p < 0.001). Patients with suicide attempts had significantly higher levels of TSH ( p < 0.001), TgAb ( p = 0.004), TPOAb ( p < 0.001), TG ( p = 0.016), TC ( p < 0.001), LDL ( p < 0.001), and fasting glucose ( p < 0.001), but significantly lower levels of HDL ( p < 0.001). Logistic regression analysis showed that marital status (OR = 0.515, 95%CI: 0.280–0.950, p = 0.515), disease duration (OR = 1.100, 95%CI: 1.013–1.194, p = 0.024), HAMA score (OR = 1.313, 95%CI: 1.205–1.430, p < 0.001), CGI-S score (OR = 1.875, 95%CI: 1.339–2.624, p < 0.001), levels of FT3(OR = 0.717, 95%CI: 0.536–0.959, p = 0.025), TPOAb (OR = 1.004, 95%CI: 1.002–1.006, p < 0.001), TC (OR = 1.330, 95%CI: 1.011–1.750, p = 0.042) and LDL (OR = 0.736, 95%CI: 0.558–0.971, p = 0.030) were all independently associated with suicide attempts in young MDD patients. Conclusions In China, the rate of suicide attempts in young patients with MDD is quite high and thyroid dysfunction and metabolic abnormalities may be implicated in its pathogenesis.