Clinical effects of glabellar botulinum toxin injections on borderline personality disorder: A randomized controlled trial

Botulinum Toxin Injections for Psychiatric Disorders: A Systematic Review of the Clinical Trial Landscape

Botulinum toxin type A (BONT-A) has shown promise in improving the mood-related symptoms of psychiatric disorders by targeting muscles linked to the expression of negative emotions. We conducted a systematic review of past and ongoing efficacy trials of BONT-A therapy for psychiatric disorders to identify relevant trends in the field and discuss the refinement of therapeutic techniques. A comprehensive search for published clinical trials using BONT-A injections for psychiatric disorders was performed on 4 May 2023 through OVID databases (MEDLINE, Embase, APA PsycINFO). Unpublished clinical trials were searched through the ClinicalTrials.gov and International Clinical Trial Registry Platform public registries. The risk of bias was assessed using the JBI Critical Appraisal tools for use in systematic reviews. We identified 21 studies (17 published, 4 unpublished clinical trials) involving 471 patients. The studies focused on evaluating the efficacy of BONT-A for major depressive, borderline personality, social anxiety, and bipolar disorders. BONT-A was most commonly injected into the glabellar area, with an average dose ranging between 37.75 U and 44.5 U in published studies and between 32.7 U and 41.3 U in unpublished trials. The results indicated significant symptom reductions across all the studied psychiatric conditions, with mild adverse effects. Thus, BONT-A appears to be safe and well-tolerated for psychiatric disorders of negative affectivity. However, despite the clinical focus, there was a noted shortage of biomarker-related assessments. Future studies should focus on pursuing mechanistic explorations of BONT-A effects at the neurobiological level.

Effects of glabellar botulinum toxin injections on resting-state functional connectivity in borderline personality disorder

Meta-analyses suggest a sustained alleviation of depressive symptoms through glabellar botulinum toxin (BTX) injections. This can be explained by the disruption of facial feedback loops, which may moderate and reinforce the experience of negative emotions. Borderline personality disorder (BPD) is characterized by excessive negative emotions. Here, a seed-based resting-state functional connectivity (rsFC) analysis following BTX (N = 24) or acupuncture (ACU, N = 21) treatment in BPD is presented on areas related to the motor system and emotion processing. RsFC in BPD using a seed-based approach was analyzed. MRI data were measured before and 4 weeks after treatment. Based on previous research, the rsFC focus was on limbic and motor areas as well as the salience and default mode network. Clinically, after 4 weeks both groups showed a reduction of borderline symptoms. However, the anterior cingulate cortex (ACC) and the face area in the primary motor cortex (M1) displayed aberrant rsFC after BTX compared to ACU treatment. The M1 showed higher rsFC to the ACC after BTX treatment compared to ACU treatment. In addition, the ACC displayed an increased connectivity to the M1 as well as a decrease to the right cerebellum. This study shows first evidence for BTX-specific effects in the motor face region and the ACC. The observed effects of BTX on rsFC to areas are related to motor behavior. Since symptom improvement did not differ between the two groups, a BTX-specific effect seems plausible rather than a general therapeutic effect.

Botulinum Toxin Therapy for Psychiatric Disorders in Clinical Practice: A Retrospective Case Study

Inhibiting the facial expression of negative emotions via botulinum toxin A (BTX) has been shown to mitigate symptoms of clinical depression in randomized controlled trials. This retrospective case study sought to reproduce the beneficial effects of BTX in a naturalistic setting for major depressive disorder and collect casuistic data on its effect on other mental disorders. Moreover, we describe symptom development across multiple treatment cycles with BTX, and assess the implementation of additional injection targets in the lower face region. Participants were N = 51 adult psychiatric outpatients mainly seeking treatment for depression. Over 50% suffered from comorbid psychiatric conditions, predominantly generalized anxiety disorder (GAD) or borderline personality disorder (BPD). A pre-post case series design was adapted. All participants received BTX-injections in the glabellar region on at least one occasion. Some received additional injections in the mouth region and over multiple treatment cycles. Treatment response was followed up by self-rated scales at varying time intervals post treatment. The results showed that BTX may yield favorable outcomes across multiple and comorbid mental disorders, especially, however, for patients suffering from depression. It potentially prevents the recurrence of clinical symptoms if applied regularly. Adding additional regions of the face does not seem to be superior over applying it to the glabellar region alone. The results add to the growing evidence that BTX therapy is effective in alleviating symptoms of depression. Positive effects can be sustained and reinstated, when applied over multiple treatment cycles. Observed symptom reduction in other psychiatric disorders was less pronounced. Further research is needed to understand the mechanisms by which BTX therapy reduces psychiatric symptoms.

Botulinum Toxin Treatment for Depression: A New Paradigm for Psychiatry

Multiple randomized double-blind placebo-controlled trials have shown that botulinum toxin A (BoNT/A), when injected into the frown musculature, is an antidepressant. This review outlines the conceptual narrative behind this treatment modality, starting with theory developed by Charles Darwin. We develop the concept of emotional proprioception and discuss how the muscles of facial expression play an important role in relaying valenced information to the brain's emotional neuroanatomical circuit. We review the role of facial frown musculature as the brain's barometer and transmitter of negatively valanced emotional information. The direct connections between the corrugator muscles and the amygdala are reviewed, and these provide a neuroanatomical circuit that is a logical target for treatment with BoNT/A. The centrality of amygdala dysfunction in the pathogenesis of many psychiatric disorders, and the evidence that BoNT/A modulates amygdala activity, provides the mechanistic link between BoNT/A and its antidepressant activity. Animal models of BoNT/A's antidepressant effects confirm the evolutionary conservation of this emotional circuit. The clinical and theoretical implications of this evidence, as it relates to the potential treatment of a broad range of psychiatric disorders by BoNT/A, is discussed. The ease of administration, long duration, and favorable side effect profile of this therapy is reviewed in the context of existing antidepressant treatments.

Pharmacological interventions for people with borderline personality disorder

BACKGROUND

Among people with a diagnosis of borderline personality disorder (BPD) who are engaged in clinical care, prescription rates of psychotropic medications are high, despite the fact that medication use is off-label as a treatment for BPD. Nevertheless, people with BPD often receive several psychotropic drugs at a time for sustained periods.

OBJECTIVES

To assess the effects of pharmacological treatment for people with BPD.

SEARCH METHODS

For this update, we searched CENTRAL, MEDLINE, Embase, 14 other databases and four trials registers up to February 2022. We contacted researchers working in the field to ask for additional data from published and unpublished trials, and handsearched relevant journals. We did not restrict the search by year of publication, language or type of publication.

SELECTION CRITERIA

Randomised controlled trials comparing pharmacological treatment to placebo, other pharmacologic treatments or a combination of pharmacologic treatments in people of all ages with a formal diagnosis of BPD. The primary outcomes were BPD symptom severity, self-harm, suicide-related outcomes, and psychosocial functioning. Secondary outcomes were individual BPD symptoms, depression, attrition and adverse events.

DATA COLLECTION AND ANALYSIS

At least two review authors independently selected trials, extracted data, assessed risk of bias using Cochrane's risk of bias tool and assessed the certainty of the evidence using the GRADE approach. We performed data analysis using Review Manager 5 and quantified the statistical reliability of the data using Trial Sequential Analysis.

MAIN RESULTS

We included 46 randomised controlled trials (2769 participants) in this review, 45 of which were eligible for quantitative analysis and comprised 2752 participants with BPD in total. This is 18 more trials than the 2010 review on this topic. Participants were predominantly female except for one trial that included men only. The mean age ranged from 16.2 to 39.7 years across the included trials. Twenty-nine different types of medications compared to placebo or other medications were included in the analyses. Seventeen trials were funded or partially funded by the pharmaceutical industry, 10 were funded by universities or research foundations, eight received no funding, and 11 had unclear funding. For all reported effect sizes, negative effect estimates indicate beneficial effects by active medication. Compared with placebo, no difference in effects were observed on any of the primary outcomes at the end of treatment for any medication. Compared with placebo, medication may have little to no effect on BPD symptom severity, although the evidence is of very low certainty (antipsychotics: SMD -0.18, 95% confidence interval (CI) -0.45 to 0.08; 8 trials, 951 participants; antidepressants: SMD -0.27, 95% CI -0.65 to 1.18; 2 trials, 87 participants; mood stabilisers: SMD -0.07, 95% CI -0.43 to 0.57; 4 trials, 265 participants). The evidence is very uncertain about the effect of medication compared with placebo on self-harm, indicating little to no effect (antipsychotics: RR 0.66, 95% CI 0.15 to 2.84; 2 trials, 76 participants; antidepressants: MD 0.45 points on the Overt Aggression Scale-Modified-Self-Injury item (0-5 points), 95% CI -10.55 to 11.45; 1 trial, 20 participants; mood stabilisers: RR 1.08, 95% CI 0.79 to 1.48; 1 trial, 276 participants). The evidence is also very uncertain about the effect of medication compared with placebo on suicide-related outcomes, with little to no effect (antipsychotics: SMD 0.05, 95 % CI -0.18 to 0.29; 7 trials, 854 participants; antidepressants: SMD -0.26, 95% CI -1.62 to 1.09; 2 trials, 45 participants; mood stabilisers: SMD -0.36, 95% CI -1.96 to 1.25; 2 trials, 44 participants). Very low-certainty evidence shows little to no difference between medication and placebo on psychosocial functioning (antipsychotics: SMD -0.16, 95% CI -0.33 to 0.00; 7 trials, 904 participants; antidepressants: SMD -0.25, 95% CI -0.57 to 0.06; 4 trials, 161 participants; mood stabilisers: SMD -0.01, 95% CI -0.28 to 0.26; 2 trials, 214 participants). Low-certainty evidence suggests that antipsychotics may slightly reduce interpersonal problems (SMD -0.21, 95% CI -0.34 to -0.08; 8 trials, 907 participants), and that mood stabilisers may result in a reduction in this outcome (SMD -0.58, 95% CI -1.14 to -0.02; 4 trials, 300 participants). Antidepressants may have little to no effect on interpersonal problems, but the corresponding evidence is very uncertain (SMD -0.07, 95% CI -0.69 to 0.55; 2 trials, 119 participants). The evidence is very uncertain about dropout rates compared with placebo by antipsychotics (RR 1.11, 95% CI 0.89 to 1.38; 13 trials, 1216 participants). Low-certainty evidence suggests there may be no difference in dropout rates between antidepressants (RR 1.07, 95% CI 0.65 to 1.76; 6 trials, 289 participants) and mood stabilisers (RR 0.89, 95% CI 0.69 to 1.15; 9 trials, 530 participants), compared to placebo. Reporting on adverse events was poor and mostly non-standardised. The available evidence on non-serious adverse events was of very low certainty for antipsychotics (RR 1.07, 95% CI 0.90 to 1.29; 5 trials, 814 participants) and mood stabilisers (RR 0.84, 95% CI 0.70 to 1.01; 1 trial, 276 participants). For antidepressants, no data on adverse events were identified.

AUTHORS' CONCLUSIONS

This review included 18 more trials than the 2010 version, so larger meta-analyses with more statistical power were feasible. We found mostly very low-certainty evidence that medication may result in no difference in any primary outcome. The rest of the secondary outcomes were inconclusive. Very limited data were available for serious adverse events. The review supports the continued understanding that no pharmacological therapy seems effective in specifically treating BPD pathology. More research is needed to understand the underlying pathophysiologic mechanisms of BPD better. Also, more trials including comorbidities such as trauma-related disorders, major depression, substance use disorders, or eating disorders are needed. Additionally, more focus should be put on male and adolescent samples.

Neuronal effects of glabellar botulinum toxin injections using a valenced inhibition task in borderline personality disorder

Previous studies have indicated that glabellar botulinum toxin (BTX) injections may lead to a sustained alleviation of depression. This may be accomplished by the disruption of a facial feedback loop, which potentially mitigates the experience of negative emotions. Accordingly, glabellar BTX injection can attenuate amygdala activity in response to emotional stimuli. A prototypic condition with an excess of negative emotionality and impulsivity accompanied by elevated amygdala reactivity to emotional stimuli is borderline personality disorder (BPD). In order to improve the understanding of how glabellar BTX may affect the processing of emotional stimuli and impulsivity, we conducted a functional magnetic resonance imaging (fMRI) study. Our hypotheses were (1) glabellar BTX leads to increased activation in prefrontal areas during inhibition performance and (2) BTX decreases amygdala activity during the processing of emotional stimuli in general. Using an emotional go-/no-go paradigm during fMRI, the interference of emotion processing and impulsivity in a sample of n = 45 women with BPD was assessed. Subjects were randomly assigned to BTX treatment or serial acupuncture (ACU) of the head. After 4 weeks, both treatments led to a reduction in the symptoms of BPD. However, BTX treatment was specifically associated with improved inhibition performance and increased activity in the motor cortex. In addition, the processing of negative emotional faces was accompanied by a reduction in right amygdala activity. This study provides the first evidence that glabellar BTX injections may modify central neurobiological and behavioural aspects of BPD. Since the control treatment produced similar clinical effects, these neurobiological findings may be specific to BTX and not a general correlate of symptomatic improvement.

Treatment of Depression with Botulinum Toxin

Injection of botulinum toxin (BoNT) into the glabellar region of the face is a novel therapeutic approach in the treatment of depression. This treatment method has several advantages, including few side effects and a long-lasting, depot-like effect. Here we review the clinical and experimental evidence for the antidepressant effect of BoNT injections as well as the theoretical background and possible mechanisms of action. Moreover, we provide practical instructions for the safe and effective application of BoNT in the treatment of depression. Finally, we describe the current status of the clinical development of BoNT as an antidepressant and give an outlook on its potential future role in the management of mental disorders.