Background: Placebo and nocebo effects are widely reported across psychiatric conditions, yet have seldom been examined in the context of gambling disorder. Through meta-analysis, we examined placebo effects, their moderating factors, and nocebo effects, from available randomised, controlled pharmacological clinical trials in gambling disorder. Methods: We searched, up to 19 February 2024, a broad range of databases, for double-blind randomised controlled trials (RCTs) of medications for gambling disorder. Outcomes were gambling symptom severity and quality of life (for efficacy), and drop outs due to medication side effects in the placebo arms. Results: We included 16 RCTs (n = 833) in the meta-analysis. The overall effect size for gambling severity reduction in the placebo arms was 1.18 (95%CI 0.91-1.46) and for quality of life improvement was 0.63 (0.42-0.83). Medication class, study sponsorship, trial duration, baseline severity of gambling and publication year significantly moderated effect sizes for at least some of these outcome measures. Author conflict of interest, placebo run-in, gender split, severity scale choice, age of participants or unbalanced randomisation did not moderate effect sizes. Nocebo effects leading to drop out from the trial were observed in 6% of participants in trials involving antipsychotics, while this was less for other medication types. Conclusion: Placebo effects in trials of pharmacological treatment of gambling disorder are large, and there are several moderators of this effect. Nocebo effects were measureable and may be influenced by medication class being studied. Practical implications of these new findings for the field are discussed, along with recommendations for future clinical trials.

Placebo and nocebo effects in gambling disorder pharmacological trials: A meta-analysis / Ioannidis, K.; Huneke, N. T. M.; Solly, J. E.; Fusetto Veronesi, G.; Tzagarakis, C.; Parlatini, V.; Westwood, S. J.; Del Giovane, C.; Baldwin, D. S.; Grant, J. E.; Cortese, S.; Chamberlain, S. R.. - In: ACTA NEUROPSYCHIATRICA. - ISSN 0924-2708. - (2024), pp. 1-11. [10.1017/neu.2024.52]

Placebo and nocebo effects in gambling disorder pharmacological trials: A meta-analysis

Del Giovane C.;
2024

Abstract

Background: Placebo and nocebo effects are widely reported across psychiatric conditions, yet have seldom been examined in the context of gambling disorder. Through meta-analysis, we examined placebo effects, their moderating factors, and nocebo effects, from available randomised, controlled pharmacological clinical trials in gambling disorder. Methods: We searched, up to 19 February 2024, a broad range of databases, for double-blind randomised controlled trials (RCTs) of medications for gambling disorder. Outcomes were gambling symptom severity and quality of life (for efficacy), and drop outs due to medication side effects in the placebo arms. Results: We included 16 RCTs (n = 833) in the meta-analysis. The overall effect size for gambling severity reduction in the placebo arms was 1.18 (95%CI 0.91-1.46) and for quality of life improvement was 0.63 (0.42-0.83). Medication class, study sponsorship, trial duration, baseline severity of gambling and publication year significantly moderated effect sizes for at least some of these outcome measures. Author conflict of interest, placebo run-in, gender split, severity scale choice, age of participants or unbalanced randomisation did not moderate effect sizes. Nocebo effects leading to drop out from the trial were observed in 6% of participants in trials involving antipsychotics, while this was less for other medication types. Conclusion: Placebo effects in trials of pharmacological treatment of gambling disorder are large, and there are several moderators of this effect. Nocebo effects were measureable and may be influenced by medication class being studied. Practical implications of these new findings for the field are discussed, along with recommendations for future clinical trials.
2024
1
11
Placebo and nocebo effects in gambling disorder pharmacological trials: A meta-analysis / Ioannidis, K.; Huneke, N. T. M.; Solly, J. E.; Fusetto Veronesi, G.; Tzagarakis, C.; Parlatini, V.; Westwood, S. J.; Del Giovane, C.; Baldwin, D. S.; Grant, J. E.; Cortese, S.; Chamberlain, S. R.. - In: ACTA NEUROPSYCHIATRICA. - ISSN 0924-2708. - (2024), pp. 1-11. [10.1017/neu.2024.52]
Ioannidis, K.; Huneke, N. T. M.; Solly, J. E.; Fusetto Veronesi, G.; Tzagarakis, C.; Parlatini, V.; Westwood, S. J.; Del Giovane, C.; Baldwin, D. S.; ...espandi
File in questo prodotto:
File Dimensione Formato  
unpaywall-bitstream-699391792.pdf

Open access

Tipologia: VOR - Versione pubblicata dall'editore
Dimensione 827.5 kB
Formato Adobe PDF
827.5 kB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Licenza Creative Commons
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/1368006
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 1
  • ???jsp.display-item.citation.isi??? 1
social impact