Influence of study characteristics, methodological rigour and publication bias on efficacy of pharmacotherapy in obsessive-compulsive disorder: a systematic review and meta-analysis of randomised, placebo-controlled trials

QUESTION

We examined the effect of study characteristics, risk of bias and publication bias on the efficacy of pharmacotherapy in randomised controlled trials (RCTs) for obsessive-compulsive disorder (OCD).

STUDY SELECTION AND ANALYSIS

We conducted a systematic search of double-blinded, placebo-controlled, short-term RCTs with selective serotonergic reuptake inhibitors (SSRIs) or clomipramine. We performed a random-effect meta-analysis using change in the Yale-Brown Obsessive-Compulsive Scale (YBOCS) as the primary outcome. We performed meta-regression for risk of bias, intervention, sponsor status, number of trial arms, use of placebo run-in, dosing, publication year, age, severity, illness duration and gender distribution. Furthermore, we analysed publication bias using a Bayesian selection model.

FINDINGS

We screened 3729 articles and included 21 studies, with 4102 participants. Meta-analysis showed an effect size of -0.59 (Hedges' G, 95% CI -0.73 to -0.46), equalling a 4.2-point reduction in the YBOCS compared with placebo. The most recent trial was performed in 2007 and most trials were at risk of bias. We found an indication for publication bias, and subsequent correction for this bias resulted in a depleted effect size. In our meta-regression, we found that high risk of bias was associated with a larger effect size. Clomipramine was more effective than SSRIs, even after correcting for risk of bias. After correction for multiple testing, other selected predictors were non-significant.

CONCLUSIONS

Our findings reveal superiority of clomipramine over SSRIs, even after adjusting for risk of bias. Effect sizes may be attenuated when considering publication bias and methodological rigour, emphasising the importance of robust studies to guide clinical utility of OCD pharmacotherapy.

PROSPERO REGISTRATION NUMBER

CRD42023394924.

Electroencephalography for predicting antidepressant treatment success: A systematic review and meta-analysis

BACKGROUND

Patients suffering from major depressive disorder (MDD) regularly experience non-response to treatment for their depressive episode. Personalized clinical decision making could shorten depressive episodes and reduce patient suffering. Although no clinical tools are currently available, machine learning analysis of electroencephalography (EEG) shows promise in treatment response prediction.

METHODS

With a systematic review and meta-analysis, we evaluated the accuracy of EEG for individual patient response prediction. Importantly, we included only prediction studies that used cross-validation. We used a bivariate model to calculate prediction success, as expressed by area-under the curve, sensitivity and specificity. Furthermore, we analyzed prediction success for separate antidepressant interventions.

RESULTS

15 studies with 12 individual patient samples and a total of 479 patients were included. Research methods varied considerably between studies. Meta-analysis of results from this heterogeneous set of studies resulted in an area under the curve of 0.91, a sensitivity of 83 % (95 % CI 74-89 %), and a specificity of 86 % (95 % CI 81-90 %). Classification performance did not significantly differ between treatments. Although studies were all internally validated, no externally validated studies have been reported. We found substantial risk of bias caused by methodological shortcomings such as non-independent feature selection, though performance of non-biased studies was comparable.

LIMITATIONS

Sample sizes were relatively small and no study used external validation, increasing the risk of overestimation of accuracy.

CONCLUSIONS

Electroencephalography can predict the response to antidepressant treatment with high accuracy. However, future studies with more rigorous validation are needed to produce a clinical tool to guide interventions in MDD.

PROSPERO REGISTRATION NUMBER

CRD42021268169.

'Rapid speed of response to ECT in bipolar depression: A chart review

OBJECTIVE

To validate a faster speed of response to electroconvulsive therapy (ECT) for bipolar depression (BPD) compared to major depressive disorder (MDD) METHOD: Retrospective chart review on an ECT cohort in an academic hospital setting. Speed of response was defined by the number of ECT treatments needed for response or remission.

RESULTS

Sixty-four depressed patients were included, of whom 53 (MDD: 40, BPD: 13) could be analyzed. The bipolar group responded faster with a mean difference of 3.3 fewer ECT treatments to meet response criteria (MDD 10.4 vs. BPD 7.1, p = 0.054). When using mixed effects regression models for the response/remitter group (n = 35), a faster response for the bipolar group (AIC 252.83 vs 258.55, χ² = 11.72, p = 0.008) was shown. Other factors, such as psychotic features or comorbidity, did not influence the speed of response.

CONCLUSION

This chart review of an ECT cohort in an naturalistic academic hospital setting shows an evident and clinically relevant faster speed of response in bipolar depression.

Conscious perception and the modulatory role of dopamine: no effect of the dopamine D2 agonist cabergoline on visual masking, the attentional blink, and probabilistic discrimination

RATIONALE

Conscious perception is thought to depend on global amplification of sensory input. In recent years, striatal dopamine has been proposed to be involved in gating information and conscious access, due to its modulatory influence on thalamocortical connectivity.

OBJECTIVES

Since much of the evidence that implicates striatal dopamine is correlational, we conducted a double-blind crossover pharmacological study in which we administered cabergoline-a dopamine D2 agonist-and placebo to 30 healthy participants. Under both conditions, we subjected participants to several well-established experimental conscious-perception paradigms, such as backward masking and the attentional blink task.

RESULTS

We found no evidence in support of an effect of cabergoline on conscious perception: key behavioral and event-related potential (ERP) findings associated with each of these tasks were unaffected by cabergoline.

CONCLUSIONS

Our results cast doubt on a causal role for dopamine in visual perception. It remains an open possibility that dopamine has causal effects in other tasks, perhaps where perceptual uncertainty is more prominent.

[Electroconvulsion therapy for persistent depression in the Netherlands; very low application rate]

Of all depressive disorders, 20% has a persistent course. For persistent depressive patients, electroconvulsive therapy (ect) is recommended for this patient population, since it is the most potent treatment for depression. The Dutch depression guideline advises the use of ect for persistent depressive disorder at approximately 12 months after inadequate efficacy of psychotherapy and/or pharmacological treatment.<br/> AIM: To quantify the use of electroconvulsive therapy in persistent depressive patients in the Netherlands.<br/> METHOD: Quantitative research using the Dutch registration system (diagnosis-treatment-combination; dbc) information system (dis) of the Dutch Healthcare Authority (nza).<br/> RESULTS: Of the patients within the dbc system (in 2014) with the main diagnosis of unipolar depression, 23,597 (26%) were registered for more than two years and could be classified as having a persistent depressive episode. Of these latter patients, only 278 (1.2%) received ect.<br/> CONCLUSION: In the Netherlands, only 1.2% of patients with a persistent depression received ect, whereas this treatment could have been considered for 26% of this group. The low application rate might be caused by professionals' inadequate knowledge about ect and the premature use of the handicap model.

[Reaction on 'Persistant underuse of ECT for persistant depressive disorder?']

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