Between September 2009 and February 2010, 82 Korean HIV-infected patients were recruited to the study from two university hospitals. Two trained monitors collected demographic, clinical, laboratory, and pharmacological data using structured case report forms that gathered information on age, sex, marital status, employment status, comorbidities, route of HIV transmission, opportunistic diseases, HAART regimens, duration of HAART treatment, and adherence to treatment. Unemployment was defined as a situation in which a subject of working age could not obtain a job but would like to be in full-time employment. Temporary employment was regarded as unemployment, while housewives were considered employed. Adherence to clinic visits was evaluated by reviews of electronic medical records that revealed the number of missed clinical appointments (per year) and the cumulative loss of time to follow-up (days per month). HAART was classified into three regimens: the boosted protease inhibitor (PI)-based regimen, the unboosted protease inhibitor (PI)-based regimen, and the non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen. CD4 T-cell counts and HIV-1 RNA loads were serially recorded, with values noted at the time of HIV diagnosis, at the time of study entry (baseline), and 6 months (± 2 weeks) later.

The primary endpoint of the current study was to estimate the prevalence of depression and accompanying anxiety disorders among HIV-infected patients. In addition, subjects with depression were compared to those without depression with respect to demographics, comorbidities, CD4 T-cell count, RNA copy numbers, HAART regimen, and adherence.

This study was approved by the ethics committee of each involved institution (Korea University Guro Hospital and Inha University Hospital) and was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. All subjects provided written informed consent prior to enrollment.

Depression was measured using the Beck Depression Inventory (BDI), a 21-question multiple-choice self-report inventory. The BDI is one of the most commonly used instruments in research and practice to measure the presence and severity of depression [11,12]. We used cutoff scores as recommended by Han et al., which were based on data from a Korean sample, with scores of ≥21 indicating depression [12]. Anxiety symptoms were evaluated with the State-Trait Anxiety Inventory (STAI) developed by Spielberger et al. in 1970, which has been translated and standardized for use in Korea [13]. The STAI consists of two self-evaluation scales designed to separately assess state anxiety and trait anxiety. The state anxiety scale evaluates transitory state anxiety, in which unpleasant feelings, tension, and intensity vary according to the situation. The trait anxiety scale assesses a long-term personality characteristic. In this study, the state anxiety scale was evaluated and clinically significant levels of state anxiety were defined as scores ≥ 50. All patients filled out the questionnaires independently.

We conducted descriptive analyses and comparisons to examine the demographic and clinical characteristics of depressive patients. Data processing and evaluation were performed using SPSS 12.0 (SPSS Inc., Chicago, IL, USA). For categorical variables, analysis was performed using either the chi-square test or Fisher's exact test. Continuous variables were compared using the Student's t-test or Mann-Whitney U-test, as appropriate. All P-values were two-tailed, and P < 0.05 was considered to be statistically significant.