Depression is prevalent among patients with ankylosing spondylitis (AS), according to research results published in Psychiatry Investigation, and additional research is needed to identify the most effective strategies for depression treatment and prevention in this patient population.
Researchers conducted a systematic literature review to determine the prevalence of depression in patients with AS; they also compared depression prevalence and scores in patients with AS compared with those without AS. Eligible studies were observational (cross-sectional or prospective), including baseline data of randomized controlled trials, and measured depression by self-reported symptom scales, physician diagnosis, or structured diagnostic interview.
Of the 598 studies identified, 31 met the eligibility criteria and were included in the current study. These studies included a total of 8106 patients (75.9% men) with a mean age of 39.2 years; mean disease duration of study participants was 10.64 years.
Depression assessments were conducted in multiple different ways: 13 studies assessed depression using the Hospital Anxiety and Depression Scale, 5 used the 21 Item-Beck Depression Inventory, 6 used the Zung Self-Rating Depression Scale, 3 assessed depression by a structured interview, and 3 studies used other screening tools.
In individual studies, the prevalence estimates of depression varied from 3% to 66% of patients with AS. Overall, the pooled prevalence of depression was 35% (95% CI, 28%-43%) with high between-study heterogeneity (I²=98.8%; P <.001). According to the Hospital Anxiety and Depression Scale, the prevalence estimate was 9%, and thresholds were 11% to 49% for the 21-Item Beck Depression Inventory. Major depressive disorder prevalence was 13%, according to structured interviews.
A total of 8 studies compared depression prevalence estimates in AS with non-AS groups, resulting in a pooled risk ratio of 1.76 (n=3006; 95% CI, 1.21-2.55). In 7 studies that compared depression in the two groups, depression scores were higher in patients with AS than in those without AS (standardized mean difference, 0.43; 95% CI, 0.19-0.67).
Sensitivity analyses found that when excluding studies with less sample representativeness, depression prevalence estimates tended to decrease. Pooled standardized mean difference decreased in patients with AS vs in those without AS when studies using only samples of men were excluded. Subgroup analysis results found that studies with a sample size <200 had higher depression prevalence estimates (52%; 95% CI, 44%-60%) compared with primary analysis (42%; 95% CI, 39%-45%), according to the Hospital Anxiety and Depression Scale, and also higher pooled risk ratios in patients with AS.
Study limitations included a substantial amount of heterogeneity among the studies, and inadequate data to conduct subgroup analyses by sex, disease duration, and age.
“One-third of [patients] with AS experienced symptoms of depression,” the researchers concluded. “Further research is needed to identify effective strategies for preventing and treating depression among [patients with AS].”
Zhang L, Wu Y, Liu S, Zhu W. Prevalence of depression in ankylosing spondylitis: a systematic review and meta-analysis. Psychiatry Investig. 2019;16(8):565-574.