Background: Psychological distress is the major comorbidity among tuberculosis (TB) patients. However, its magnitude, associated factors, and effect on treatment outcome have not been adequately studied in low-income countries. Objective: This study aimed to determine the magnitude of psychological distress and its effect on treatment outcome among TB patients on treatment. Design: A follow-up study was conducted in Addis Ababa, Ethiopia, from May to December 2014. Patients (N=330) diagnosed with all types of TB who had been on treatment for 1-2 months were enrolled consecutively from 15 randomly selected health centers and one TB specialized hospital. Data on sociodemographic variables and economic status were collected using a structured questionnaire. The presence of psychological distress was assessed at baseline (within 1-2 months after treatment initiation) and end point (6 months after treatment initiation) using the 10-item Kessler (K-10) scale. Alcohol use and tobacco smoking history were assessed using WHOAlcohol Use Disorder Identification Test and Australian Smoking Assessment Checklist, respectively. The current WHO TB treatment outcome definition was used to differentiate the end result of each patient at completion of the treatment. Results: The overall psychological distress was 67.6% at 1-2 months and 48.5% at 6 months after treatment initiation. Multiple logistic regression analysis revealed that past TB treatment history [adjusted odds ratio (AOR): 3.76; 95% confidence interval (CI): 1.67-8.45], being on anti-TB and anti-HIV treatments (AOR: 5.35; 95% CI: 1.83-15.65), being unmarried (AOR: 4.29; 95% CI: 2.45-7.53), having alcohol use disorder (AOR: 2.95; 95% CI: 1.25-6.99), and having low economic status (AOR: 4.41; 95% CI: 2.44-7.97) were significantly associated with psychological distress at baseline. However, at 6 months after treatment initiation, only being a multidrug-resistant tuberculosis (MDR-TB) patient (AOR: 3.02; 95% CI: 1.17-7.75) and having low economic status (AOR: 3.75; 95% CI: 2.08-6.74) were able to predict psychological distress significantly. Past TB treatment history (AOR: 2.13; 95% CI: 1.10-4.12), employment status (AOR: 2.06; 95% CI: 1.06-7.00), and existence of psychological distress symptoms at 6 months after treatment initiation (AOR: 2.87; 95% CI: 1.05-7.81) were found to be associated with treatment outcome. Conclusions: The overall magnitude of psychological distress was high across the follow-up period; this was more pronounced at baseline. At baseline, past TB treatment history, being on anti-TB and anti-HIV treatments, being unmarried, and having symptoms of alcohol use disorder were associated with psychological distress. However, both at baseline and end point, low economic status was associated with psychological distress. Screening and treatment of psychological distress among TB patients across the whole treatment period is needed, and focusing more on patients who have been economically deprived, previously treated for TB, and on MDR-TB treatment are important.
