Background: Inhibition of frowning via injections of botulinum toxin A (BTX) into
the glabellar region has shown beneficial effects in the treatment of major depression.
Preliminary research suggests that improvements in the affective domain are not depression-specific,
but may also translate to other psychiatric disorders. Aim: This 16-week, single-blind,
two-center randomized controlled trial investigated the influence of BTX on clinical
symptoms of borderline personality disorder (BPD). Methods: Fifty-four patients with
BPD were randomly assigned to treatment with BTX (n = 27) or a minimal acupuncture
(ACU) control condition (n = 27). Clinical outcomes were followed at 2, 4, 6, 8, 12,
and 16 weeks. Primary endpoint was the relative score change on the Zanarini Rating
Scale for Borderline Personality Disorder (ZAN-BPD) 8 weeks after baseline relative
to the control group and adjusted for treatment center. Secondary and additional outcome
variables were self-rated borderline symptoms, comorbid symptoms of depression, psychological
distress, and clinical global impression. Results: Participants showed significant
improvements at the primary efficacy endpoint in both treatment groups (BTX: M = -0.39,
SD = 0.39; ACU: M = -0.35, SD = 0.42), but no superior effect of the BTX condition
in comparison with the control intervention was found-F(1,5323) = 0.017, p = 0.68).
None of the secondary or additional outcomes yielded significant group differences.
Side effects were mild and included headache, transient skin or muscle irritations,
and dizziness. Conclusion: Evidence regarding the efficacy of BTX for BDP remains
limited, and the design of adequate control conditions presents an opportunity for
further research.
