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Solaja I, Haldane K, Mason N, Weiss B, Xu X, Xu M, Nikolin S, Jayasena T, Millard M, Brett J, Bayes A, Loo CK, Martin DM. Who are you after psychedelics? A systematic review and a meta-analysis of the magnitude of long-term effects of serotonergic psychedelics on cognition/creativity, emotional processing and personality. Neurosci Biobehav Rev 2024; 158:105570. [PMID: 38311046 DOI: 10.1016/j.neubiorev.2024.105570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 01/29/2024] [Accepted: 01/31/2024] [Indexed: 02/06/2024]
Abstract
This systematic review and a meta-analysis synthesised the results from contemporary, randomized and non-randomized controlled studies to assess lasting (one week minimum) changes on cognition/creativity, emotional processing and personality from serotonergic psychedelics. PubMed, Embase and PsycInfo were searched in July 2022. Risk of bias was assessed using Rob 2.0 and ROBINS-I. Ten studies met the eligibility criteria which involved 304 participants. No statistically significant effects were found for the majority outcome measures across the three constructs. A meta-analysis of emotional recognition outcomes found an overall significant effect for faster reaction times in the active treatment groups for disgust (SMD=-0.63, 95% CI=[-1.01 to -0.25], I2 = 65%) and sadness (SMD=-0.45, 95% CI=[-0.85 to -0.06], I2 = 60%). Future research should include larger samples, better control conditions, standardized doses and longer follow-up periods to confirm these preliminary findings.
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Affiliation(s)
- Ivana Solaja
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia.
| | | | - Natasha Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Brandon Weiss
- Centre for Psychedelic Research, Division of Academic Psychiatry, Imperial College London, London, UK
| | - Xiaomin Xu
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Mei Xu
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Stevan Nikolin
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia; Black Dog Institute, Sydney, Australia
| | - Tharusha Jayasena
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | | | | | - Adam Bayes
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia; Black Dog Institute, Sydney, Australia
| | - Colleen K Loo
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia; Black Dog Institute, Sydney, Australia
| | - Donel M Martin
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia; Black Dog Institute, Sydney, Australia
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2
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Goodwin GM, Croal M, Marwood L, Malievskaia E. Unblinding and demand characteristics in the treatment of depression. J Affect Disord 2023; 328:1-5. [PMID: 36781142 DOI: 10.1016/j.jad.2023.02.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 02/13/2023]
Abstract
Blinding of treatment allocation in clinical trials in psychiatry is regarded as an ideal. The potential impact of unblinding chimes with a general concern for psychological research: so-called demand characteristics can undermine confidence in findings from experimental and clinical studies. Scepticism can result in nihilism. The reliance on subjective report of symptoms in clinical trials of drug efficacy in depression provides an important example. It is regularly implied that if subjective effects, including specific adverse reactions, unblind participants to an active treatment then evidence for its efficacy is suspect. In fact, the strong association between dose and subjective effects does not translate into a strong relationship with efficacy in randomised controlled trials (RCTs) of conventional antidepressant drugs; this observation falsifies the proposition that unblinding is the principal mechanism driving RCT outcomes in studies of depression. Instead, changes in brain function, that occur soon after treatment starts, do predict treatment outcomes and align with our understanding of neurotransmitter effects from neuroscience. Psychedelic experience for the treatment of depression must be unblinding, but the effect results directly from serotonergic receptor activation and changes in brain connectivity. Where such effects are part of a novel mechanism of action, a strong dose response relationship would be expected, irrespective of unblinding. We highlight the importance of exploring blinding as a mechanism, confirming dose-related outcomes, and dissociating unblinding effects from efficacy. Unblinding does not necessarily invalidate the subjective experience of sustained recovery from depression.
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Affiliation(s)
| | - Megan Croal
- COMPASS Pathfinder Ltd, London, United Kingdom
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3
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Huneke NTM. Is superiority to placebo the most appropriate measure of efficacy in trials of novel psychotropic medications? Eur Neuropsychopharmacol 2022; 62:7-9. [PMID: 35810615 DOI: 10.1016/j.euroneuro.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/06/2022] [Accepted: 06/09/2022] [Indexed: 11/04/2022]
Affiliation(s)
- Nathan T M Huneke
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK; Academic Centre, College Keep, University Department of Psychiatry, 4-12 Terminus Terrace, Southampton SO14 3DT, UK.
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Lindberg F, Nelson I, Ranstam J, Riker DK. Early intervention with a glycerol throat spray containing cold-adapted cod trypsin after self-diagnosis of common cold: A randomised trial. PLoS One 2022; 17:e0270699. [PMID: 35789217 PMCID: PMC9255730 DOI: 10.1371/journal.pone.0270699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 05/21/2022] [Indexed: 11/18/2022] Open
Abstract
Background
A glycerol throat spray containing cold-adapted cod trypsin (GCTS) deactivates common cold virus in vitro and decreases pharyngeal rhinovirus load after inoculation in humans. We relied on early self-diagnosis and evaluated two different scales to detect a treatment effect in naturally occurring common colds.
Methods
Adults were enrolled in this randomised, prospective, parallel group, single-blind study to begin treatment six times daily at first sign of a common cold or were assigned to a non-treated group. Jackson’s symptom scale and the 9-item Wisconsin Upper Respiratory Symptom Survey (WURSS)-21 quality of life (QoL) domain were recorded daily by subjects and area under the curve over 12 days (AUC1-12) calculated.
Results
Treatment resulted in reduced symptoms with an AUC1-12 of 45.1 ± 32.5 for Jackson scores compared to 53.8 ± 35.7 in the controls (p = 0.023). AUC1-12 for the 9-item WURSS-21 QoL domain was likewise improved, 113.6 ± 107.7 and 152.7 ± 126.3 (p = 0.006), respectively. During the first four days fewer of the treated subjects (35.3%) used rescue medication than did the control group (50.4%, p = 0.014).
Conclusions
Reduction in common cold symptoms was seen with treatment with a glycerol throat spray containing cold-adapted cod trypsin. This effect was best detected with the 9-item WURSS-21 QoL domain.
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Affiliation(s)
| | | | | | - Donald K. Riker
- On Point Advisors, LLC, Scottsdale, AZ, United States of America
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Baker J, Gamer M, Rauh J, Brassen S. Placebo induced expectations of mood enhancement generate a positivity effect in emotional processing. Sci Rep 2022; 12:5345. [PMID: 35351936 PMCID: PMC8964732 DOI: 10.1038/s41598-022-09342-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/21/2022] [Indexed: 11/09/2022] Open
Abstract
A perceptual bias towards negative emotions is a consistent finding in mood disorders and a major target of therapeutic interventions. Placebo responses in antidepressant treatment are substantial, but it is unclear whether and how underlying expectancy effects can modulate response biases to emotional inputs. In a first attempt to approach this question, we investigated how placebo induced expectation can shape the perception of specific emotional stimuli in healthy individuals. In a controlled cross-over design, positive treatment expectations were induced by verbal instructions and a hidden training manipulation combined with an alleged oxytocin nasal spray before participants performed an emotion classification task on happy and fearful facial expressions with varying intensity. Analyses of response criterion and discrimination ability as derived from emotion-specific psychometric functions demonstrate that expectation specifically lowered participants’ threshold for identifying happy emotions in general, while they became less sensitive to subtle differences in emotional expressions. These indications of a positivity bias were directly correlated with participants’ treatment expectations as well as subjective experiences of treatment effects and went along with a significant mood enhancement. Our findings show that expectations can induce a perceptual positivity effect in healthy individuals which is probably modulated by top-down emotion regulation and which may be able to improve mood state. Clinical implications of these promising results now need to be explored in studies of expectation manipulation in patients with mood disorders.
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Kaltenboeck A, Ruzickova T, Breunhölder V, Zghoul T, Cowen PJ, Harmer CJ. No antidepressant-like acute effects of bright light on emotional information processing in healthy volunteers. Psychopharmacology (Berl) 2022; 239:277-286. [PMID: 34743231 PMCID: PMC8770384 DOI: 10.1007/s00213-021-06003-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 10/12/2021] [Indexed: 01/10/2023]
Abstract
RATIONALE Bright light treatment (BLT) is an efficacious antidepressant intervention, but its mechanism of action is not well understood. Antidepressant drugs acutely affect how emotional information is processed, pushing the brain to prioritise positive relative to negative input. Whether BLT could have a similar effect is not known to date. OBJECTIVE To test whether BLT acutely influences emotional information processing similar to antidepressant drugs, using an established healthy volunteer assay. METHODS Following a double-blind, parallel-group design, 49 healthy volunteers (18-65 years, 26 females) were randomly allocated to 60-min BLT (≥ 10,000 lux) or sham-placebo treatment early in the morning in autumn/winter. Immediately after treatment, emotional information processing was assessed using the Oxford Emotional Test Battery, a validated set of behavioural tasks tapping into emotional information processing in different cognitive domains. Participants also completed questionnaires before and after treatment to assess changes in subjective state. RESULTS The BLT group did not show significantly more positively biased emotional information processing compared to the placebo group (p > 0.05 for all measures). After adjustment for pre-treatment scores, there were also no significant post-treatment differences between groups in subjective state (p > 0.05 for all measures). CONCLUSIONS BLT did not show immediate effects on emotional information processing in an established healthy volunteer assay. Thus, BLT might exert its clinical effects through a different (cognitive) mechanism than other antidepressant interventions. Future studies should corroborate this finding including clinical populations and more intensive treatment regimes, and control for potential chronobiological effects.
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Affiliation(s)
- Alexander Kaltenboeck
- Department of Psychiatry, University of Oxford, Oxford, UK. .,Clinical Division of Social Psychiatry, Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria.
| | - Tereza Ruzickova
- grid.4991.50000 0004 1936 8948Department of Psychiatry, University of Oxford, Oxford, UK
| | - Veronika Breunhölder
- grid.4305.20000 0004 1936 7988School of Mathematics and Maxwell Institute for Mathematical Sciences, University of Edinburgh, Edinburgh, UK
| | - Tarek Zghoul
- grid.4991.50000 0004 1936 8948Department of Psychiatry, University of Oxford, Oxford, UK ,grid.416938.10000 0004 0641 5119Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK
| | - Philip J. Cowen
- grid.4991.50000 0004 1936 8948Department of Psychiatry, University of Oxford, Oxford, UK ,grid.416938.10000 0004 0641 5119Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK
| | - Catherine J. Harmer
- grid.4991.50000 0004 1936 8948Department of Psychiatry, University of Oxford, Oxford, UK ,grid.416938.10000 0004 0641 5119Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK
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Dawson GR, Post A, Smart TS, Browning M, Harmer CJ. Accuracy in recognising happy facial expressions is associated with antidepressant response to a NOP receptor antagonist but not placebo treatment. J Psychopharmacol 2021; 35:1473-1478. [PMID: 34608842 DOI: 10.1177/02698811211044684] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Clinical trials with putative antidepressants can be difficult to execute as it can take up to 8 weeks before differences emerge between drug and placebo, and long expensive trials often fail. Implementation of early response biomarkers could aid this process significantly with potential to identify new treatments. AIMS In a secondary analysis, we examined the association of early effects on emotional processing with later clinical outcome following treatment with the novel NOP antagonist LY2940094 versus placebo. We hypothesised that early induction of positive bias would be associated with reduced severity of depression after 8 weeks of treatment. METHODS This was a multicentre, randomised, double-blind, parallel-group, fixed-dose, placebo-controlled, 8 week study to assess sensitivity of the facial emotional recognition task (FERT) to early changes in emotional bias induced by LY2940094. Patients who met diagnostic criteria for major depression were randomised to receive LY2940094 (N = 70) or placebo (N = 66). At week 1 and 6, the FERT was completed by 33 patients in the LY2940094 group and 34 in the placebo group. RESULTS Patients identified happy faces with higher accuracy (Wald χ2(1,33) = 14.25, p < 0.001) after 1 week treatment with LY290094 compared to placebo (Wald χ2(1,32) = 0.83, p = 0.36) and this correlated with eventual treatment response measured by the Hamilton Depression Rating Scale 7 weeks later. CONCLUSION These data suggest that emotional processing biomarkers may be sensitive to early effects of antidepressant treatment indicative of later clinical response. Further studies in this area may be useful in developing new treatments and clinical trial designs for predicting antidepressant response.
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Affiliation(s)
| | | | | | - Michael Browning
- University Department of Psychiatry, Warneford Hospital, Oxford, UK.,Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK
| | - Catherine J Harmer
- University Department of Psychiatry, Warneford Hospital, Oxford, UK.,Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, UK
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Abstract
BACKGROUND Both acute and chronic pain can disrupt reward processing. Moreover, prolonged prescription opioid use and depressed mood are common in chronic pain samples. Despite the prevalence of these risk factors for anhedonia, little is known about anhedonia in chronic pain populations. METHODS We conducted a large-scale, systematic study of anhedonia in chronic pain, focusing on its relationship with opioid use/misuse, pain severity, and depression. Chronic pain patients across four distinct samples (N = 488) completed the Snaith-Hamilton Pleasure Scale (SHAPS), measures of opioid use, pain severity and depression, as well as the Current Opioid Misuse Measure (COMM). We used a meta-analytic approach to determine reference levels of anhedonia in healthy samples spanning a variety of countries and diverse age groups, extracting SHAPS scores from 58 published studies totaling 2664 psychiatrically healthy participants. RESULTS Compared to healthy samples, chronic pain patients showed higher levels of anhedonia, with ~25% of patients scoring above the standard anhedonia cut-off. This difference was not primarily driven by depression levels, which explained less than 25% of variance in anhedonia scores. Neither opioid use duration, dose, nor pain severity alone was significantly associated with anhedonia. Yet, there was a clear effect of opioid misuse, with opioid misusers (COMM ⩾13) reporting greater anhedonia than non-misusers. Opioid misuse remained a significant predictor of anhedonia even after controlling for pain severity, depression and opioid dose. CONCLUSIONS Study results suggest that both chronic pain and opioid misuse contribute to anhedonia, which may, in turn, drive further pain and misuse.
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Affiliation(s)
- Eric L Garland
- Center on Mindfulness and Integrative Health Intervention Development, University of Utah, Salt Lake City, UT, USA
- College of Social Work, University of Utah, Salt Lake City, UT, USA
| | | | - Marie Eikemo
- Department of Psychology, University of Oslo, Norway
| | - Gernot Ernst
- Department of Psychology, University of Oslo, Norway
- Kongsberg Hospital, Norway
| | - Siri Leknes
- Department of Psychology, University of Oslo, Norway
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9
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Twenty years after ‘Listening to Prozac but hearing placebo’. Do we hear placebo even louder? HEALTH PSYCHOLOGY REPORT 2019. [DOI: 10.5114/hpr.2019.83383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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10
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Godlewska BR. Cognitive neuropsychological theory: Reconciliation of psychological and biological approaches for depression. Pharmacol Ther 2018; 197:38-51. [PMID: 30578809 DOI: 10.1016/j.pharmthera.2018.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
New antidepressants and individualized approaches to treatment, matching specific therapies to individual patients, are urgently needed. For this, a better understanding of processes underpinning the development of depressive symptoms and response to medications are required. The cognitive neuropsychological model offers a novel approach uniquely combining biological and psychological approaches to explain how antidepressants exert their effect, why there is a delay in the onset of their clinical effect, and how changes in emotional processing are an essential step for a clinical antidepressant effect to take place. The paper presents the model and its underpinnings in the form of research in both healthy and depressed individuals, as well as the potential for its practical use.
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Affiliation(s)
- Beata R Godlewska
- Psychopharmacology Research Unit, University Department of Psychiatry (PPRU), University of Oxford, Oxford, UK.
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11
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Walsh AEL, Huneke NTM, Brown R, Browning M, Cowen P, Harmer CJ. A Dissociation of the Acute Effects of Bupropion on Positive Emotional Processing and Reward Processing in Healthy Volunteers. Front Psychiatry 2018; 9:482. [PMID: 30386259 PMCID: PMC6198095 DOI: 10.3389/fpsyt.2018.00482] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 09/13/2018] [Indexed: 01/14/2023] Open
Abstract
Background: Previous research indicates that antidepressants can restore the balance between negative and positive emotional processing early in treatment, indicating a role of this effect in later mood improvement. However, less is known about the effect of antidepressants on reward processing despite the potential relevance to the treatment of anhedonia. In this study, we investigated the effects of an acute dose of the atypical antidepressant (dual dopamine and noradrenaline reuptake inhibitor) bupropion on behavioral measures of emotional and reward processing in healthy volunteers. Methods: Forty healthy participants were randomly allocated to double-blind intervention with either an acute dose of bupropion or placebo prior to performing the Emotional Test Battery (ETB) and a probabilistic instrumental learning task. Results: Acute bupropion significantly increased the recognition of ambiguous faces as happy, decreased response bias toward sad faces and reduced attentional vigilance for fearful faces compared to placebo. Bupropion also reduced negative bias compared to placebo in the emotional recognition memory task (EMEM). There was no evidence that bupropion enhanced reward processing or learning. Instead, bupropion was associated with reduced likelihood to choose high-probability wins and increased score on a subjective measure of anhedonia. Conclusions: Whilst acute bupropion decreases negative and increases positive emotional processing, it has an adverse effect on reward processing. There seems to be a dissociation of the acute effects of bupropion on positive emotional processing and reward processing, which may have clinical implications for anhedonia early in treatment.
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Affiliation(s)
- Annabel E L Walsh
- NIHR Oxford Health Biomedical Research Centre, Warneford Hospital, Oxford, United Kingdom.,Psychopharmacology and Emotion Research Laboratory, Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Nathan T M Huneke
- Psychopharmacology and Emotion Research Laboratory, Department of Psychiatry, University of Oxford, Oxford, United Kingdom.,University Department of Psychiatry, University of Southampton, Southampton, United Kingdom
| | - Randi Brown
- Psychopharmacology and Emotion Research Laboratory, Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Michael Browning
- Psychopharmacology and Emotion Research Laboratory, Department of Psychiatry, University of Oxford, Oxford, United Kingdom.,Oxford Health NHS Foundation Trust, Warneford Hospital, Oxford, United Kingdom
| | - Phil Cowen
- Psychopharmacology and Emotion Research Laboratory, Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Catherine J Harmer
- NIHR Oxford Health Biomedical Research Centre, Warneford Hospital, Oxford, United Kingdom.,Psychopharmacology and Emotion Research Laboratory, Department of Psychiatry, University of Oxford, Oxford, United Kingdom
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