PURLS / PEER REVIEWED

Antidepressant Tx for Anxiety Disorders: How Long?

Clinician Reviews. 2019 December;29(12)

References

1. Batelaan NM, Bosman RC, Muntingh A, et al. Risk of relapse after antidepressant discontinuation in anxiety disorders, obsessive-compulsive disorder, and post-traumatic stress disorder: systematic review and meta-analysis of relapse prevention trials. BMJ. 2017;358:j3927. Erratum in: BMJ. 2017;358:j4461.
2. National Institute of Mental Health. Prevalence of any anxiety disorder among adults. www.nimh.nih.gov/health/statistics/any-anxiety-disorder.shtml#part_155094. Updated November 2017. Accessed November 26, 2019.
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Results. Relapse was more likely in the stopping group (odds ratio [OR], 3.11; n = 28 studies). Heterogeneity for relapse rate was low (I² = 8.07%). Subgroup analyses by type of antidepressant, mode of discontinuation, and exclusion of patient comorbidities yielded similar results. Relapse prevalence was 16.4% in the continuation group and 36.4% in the stopping group. Additionally, time to relapse was shorter when antidepressants were discontinued (hazard ratio [HR], 3.63; n = 11 studies). Again, the heterogeneity for relapse rate was low (I2 = 0%). The original publications did not consistently report medication tolerance or withdrawal symptoms, preventing analysis of these. Dropout rates were higher in the stopping group (OR, 1.31; n = 27 studies).

WHAT’S NEW

No more guessing about how long to treat

Previously, there was limited evidence to guide decisions about the duration of antidepressant treatment for anxiety disorders. This study provides evidence that stopping antidepressants before completing 1 year of treatment increases the risk for relapse.

CAVEATS

In a word: Bias

While the authors used standard and appropriate methodologies for this type of study, some significant threats to validity remained. All but 2 studies in the analysis were industry funded. Publication bias is another potential issue, even though the authors identified and included 6 unpublished studies, 4 of which had negative results.

Additionally, the authors graded 11 of 28 trials as having a high likelihood of selective reporting bias, meaning that important portions of the original studies’ results may not have been published. Most studies were at high risk for attrition bias, resulting in loss of information when patients dropped out of the study. While this happened more often in the stopping groups, it is still possible that there are unidentified harms or unexpected outcomes in the medication groups.

While PTSD and OCD are no longer considered anxiety disorders, subgroup analyses found no difference in relapse rates between these diagnoses and the others included in the studies. Finally, a treatment duration longer than 52 weeks has not been studied, so the optimal treatment duration is unknown.

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