BackgroundGender differences in patients with major depressive disorder (MDD) are commonly reported; however, gender differences in first-episode and drug-naive (FEDN) MDD patients with comorbid suicide attempts have not been reported. This study aimed to examine potential gender differences in the prevalence and clinical correlates of comorbid abnormal thyroid function (ATF) in FEDN MDD patients with comorbid suicide attempts.MethodsA cross-sectional study of 1718 FEDN MDD patients was conducted. The demographic and clinical data were collected. The Hamilton Depression Scale (HAMD), the Hamilton Anxiety Scale (HAMA) and Positive and Negative Syndrome Scale (PANSS) were used to assess depression, anxiety and psychotic symptoms, respectively. Thyroid function parameters and blood glucose levels were measured.ResultsThere was no gender difference in the prevalence of ATF between male (78.6%, 88/112) and female MDD patients (74.8%, 175/234) with comorbid suicide attempts. In the male and female subgroups, duration of disease, HAMD score, HAMA score, anti-thyroglobulin (TgAb), thyroid peroxidases antibody (TPOAb), diastolic blood pressure (DBP), systolic blood pressure (SBP), glucose level and the rate of psychotic symptoms were higher in patients with ATF than those without ATF in MDD with comorbid suicide attempt (all P < 0.05). There was a gender main effect only on SBP (F = 7.35, P = 0.007). Furthermore, binary logistic regression analysis showed that HAMD score, DBP and glucose levels were independently with ATF in both male and female MDD patients with comorbid suicide attempts. However, anxiety symptoms, psychotic symptoms and TPOAb levels were significantly associated with ATF only in female MDD patients with comorbid suicide attempts.ConclusionOur study showed no gender differences in the prevalence of ATF in FEDN MDD patients with comorbid suicide attempts. Depression, DBP and glucose levels were associated with ATF in both male and female MDD patients with comorbid suicide attempts, whereas anxiety, psychotic symptoms and TPOAb level were correlated with ATF only in female MDD patients with suicide attempts.