Objective To investigate the relationship between the levels of T helper 17 (Th17) cell-related cytokines and the response to selective serotonin reuptake inhibitors (SSRIs) in patients with depression.

Methods A total of 98 patients with depression were selected as the study subjects, all of whom received SSRIs treatment. Based on the treatment response the reduction rate of the Hamilton Depression Rating Scale (HAMD), the patients were divided into responder group and non-responder group. The levels and change rates of Th17 cell-related cytokines before and after treatment were compared between the two groups. Pearson correlation analysis was used to explore the correlation between the HAMD reduction rate and the levels of Th17 cell-related cytokines. Multifactorial logistic regression analysis was employed to screen the influencing factors of the SSRIs treatment response. Receiver operating characteristic (ROC) curves were plotted to evaluate the predictive efficacy of Th17 cell-related cytokines for the treatment response.

Results After 12 weeks of SSRIs treatment, 64 patients (65.31%) had an HAMD reduction rate of ≥50% and were classified into responder group; the remaining 34 patients (34.69%) had an HAMD reduction rate of < 50% were classified into non-responder group. Before treatment, the level of transforming growth factor-β (TGF-β) in the responder group was lower than that in the non-responder group, while the levels of interleukin (IL)-17 and IL-6 were higher than those in the non-responder group, with statistically significant differences (P < 0.05). After treatment, the levels of TGF-β, IL-17, and IL-6 in the responder group were lower than those in the non-responder group, and the change rates of TGF-β and IL-17 in the responder group were higher than those in the non-responder group, with statistically significant differences (P < 0.05). Pearson correlation analysis showed that the HAMD reduction rate was positively correlated with the pre-treatment IL-6 level, pre-treatment IL-17 level, IL-17 change rate, and TGF-β change rate, and negatively correlated with the pre-treatment TGF-β level (P < 0.05). The results of multifactorial logistic regression analysis indicated that pre-treatment IL-6 and IL-17 were independent protective factors for the SSRIs treatment response in patients with depression, while pre-treatment TGF-β was an independent risk factor (P < 0.05). The ROC curves demonstrated that the areas under the curves for predicting the SSRIs treatment response using pre-treatment IL-6, IL-17, and TGF-β alone and their combination were 0.841, 0.694, 0.862, and 0.952, respectively.

Conclusion There are associations of Th17 cell-related cytokines (IL-17, IL-6, and TGF-β) with the SSRIs treatment response in patients with depression. The pre-treatment levels of IL-17, IL-6, and TGF-β can predict the SSRIs treatment response, and combined detection can further improve the predictive efficacy.