Participants
Participants diagnosed with MDD using DSM-IV-TR were included in psychiatric inpatients in a tertiary hospital in Taiyuan, Shanxi Province, China. The inclusion criteria consisted of: (1) age: between 18 and 65 years old; (2) Hamilton Depression Rating Scale (HDRS) score >14. The exclusion criteria consisted of: (1) any history of neurological diseases, other physical diseases and presence of comorbidities of other disorders; (2) any other mental disorders, e.g., schizophrenia, schizoaffective disorder, substance use disorder, OCD, panic disorder, generalized anxiety disorder, social phobia, post-traumatic stress disorder, Axis II personality disorders, or mental retardation; (3) Pregnancy or breastfeeding. Axis II personality disorders were excluded by using Structured Clinical Interview for DSM-IV and Axis II Personality Disorders (SCID-II) Interview. This study screened the cases in the hospital from October 2015 to October 2020, of which 1391 were diagnosed as MDD, 1088 of them aged 18-65, 362of them were diagnosed with UD and 169 of them were diagnosed with BD. 229 subjects were excluded because of lack of information on UA serum levels and HAMD score.Thus, we included for analyses 302 subjects, 142 with BD and 160 with MDD.See Figure 1.The general demographic information collected includes gender, age, years of education, age of first onset, etc.
For each patient, the drug treatment regimen is divided into mood stabilizer, antipsychotics or antidepressants. The mood stabilizer agents were lithium, valproate, lamotrigine, e.The antipsychotic agents were risperidone, aripiprazole, clozapine, olanzapine, quetiapine, paliperidone, and amisulpride. The antidepressant agents were vortioxetine, ,escitalopram, sertraline, fluoxetine, desvenlafaxine, venlafaxine, paroxetine, duloxetine, trazodone, ,mirtazapine, and fluvoxamine.
Clinical Assessment
24-item Hamilton Depression Rating Scale (HDRS) is used to assess the severity of depresssive symptoms (22), assessed by the psychologist in hospital. The HAMD scale is divided into seven structural parts: anxiety/somatization (items 10–12, 15, 17,20), cognitive disturbance (items 2, 3, 9,19-21), psychomotor retardation (items 1, 7, 8, 14), sleep disturbance (items 4–6), weight loss (item 16), diurnal variation (item 18), and hopelessness (22-24).
Assessing serum UA
Serum UA was measured during routine and standard blood examination of hospitalized patients, and measured by uricase colorimetry.
Data analysis
All the data were analyzed with SPSS Statistics for Windows (version 21.0; IBM, Armonk, NY). For the characteristics of the study sample, measurement data were described as means ± standard deviations (SD) and count data were described in numbers of cases (%). Sociodemographics, clinical characteristics, serum uric acid, HAMD scores were compared using two independant sample t-test and the chi-squared test. Changes in serum uric acid at different timepoints were analyzed by paired T-test.