Anxiety symptoms are prevalent in bipolar disorder (BD) even during periods of remission and impede treatment efficacy, prognosis and functional capacity. This highlights a pressing clinical need to identify novel effective anxiety treatments. This systematic review aimed to evaluate the evidence within the field.
Following PRISMA guidelines, we conducted a systematic search on PubMed, PsycInfo, EMBASE and Cochrane Library for randomised controlled trials (RCTs) targeting anxiety in remitted BD patients.
We identified 10 RCTs investigating the effects of psychological or pharmacological treatments on anxiety in remitted BD patients. Two studies of transdiagnostic personalised cognitive behavioural therapy (CBT) found a treatment-related reduction in anxiety. This evidence was preliminary given small sample size and use of self-report measures in a single-blind trial design, respectively. The remaining six psychological intervention trials provided more preliminary evidence due to several methodological challenges. The two pharmacological studies found anxiolytic effects of add-on olanzapine or methylene blue to lithium treatment, respectively. Nevertheless, this evidence should be interpreted with caution given high drop-out rates and substantial side-effects that may have impeded blinding.
We did not conduct a quantitative meta-analysis.
There is preliminary evidence for beneficial effects of modified CBT and add-on pharmacotherapy on residual anxiety in BD. Future trials should pre-screen participants for anxiety, define one clinician-rated anxiety measurement as a primary outcome, and employ intention-to-treat analysis to assess treatment effect. This will advance treatment development and enable personalised approaches to address residual anxiety in BD, which has great clinical relevance.

Copyright © 2020. Published by Elsevier B.V.