-
Physiology & Behavior Jun 2024The roles of metabolic signals, including Glucagon-like peptide 1 (GLP-1), have been implicated in multiple domains outside metabolic regulation. There is a growing... (Review)
Review
INTRODUCTION
The roles of metabolic signals, including Glucagon-like peptide 1 (GLP-1), have been implicated in multiple domains outside metabolic regulation. There is a growing interest in repurposing Glucagon-like peptide 1 receptor agonists (GLP-1RAs) as therapeutics for motivation and reward-related behavioural disturbances. Herein, we aim to systematically review the extant evidence on the potential effects of GLP-1RAs on the reward system.
METHODS
The study followed PRISMA guidelines using databases such as OVID, PubMed, Scopus, and Google Scholar. The search focused on "Reward Behavior" and "Glucagon Like Peptide 1 Receptor Agonists" and was restricted to human studies. Quality assessment achieved by the NIH's Quality Assessment of Controlled Intervention Studies RESULTS: GLP-1RAs consistently reduced energy intake and influenced reward-related behaviour. These agents have been associated with decreased neurocortical activation in response to higher rewards and food cues, particularly high-calorie foods, and lowered caloric intake and hunger levels.
DISCUSSION
GLP-1RAs show promise in addressing reward dysfunction linked to food stimuli, obesity, and T2DM. They normalize insulin resistance, and might also modulate dopaminergic signalling and reduce anhedonia. Their effects on glycemic variability and cravings suggest potential applications in addiction disorders.
PubMed: 38945189
DOI: 10.1016/j.physbeh.2024.114622 -
European Neuropsychopharmacology : the... Jun 2024Ketamine, an N-methyl-D-aspartate receptor antagonist, is a racemic mixture of esketamine and arketamine used to treat unipolar and bipolar depression. Preliminary... (Review)
Review
Ketamine, an N-methyl-D-aspartate receptor antagonist, is a racemic mixture of esketamine and arketamine used to treat unipolar and bipolar depression. Preliminary reports indicate that it may be beneficial for depressed patients reporting symptoms of anhedonia. In this systematic review we aim to assess and analyze the existing body of evidence regarding the therapeutic effects of ketamine on the domain of anhedonia. Electronic databases (PubMed, APA Psycinfo and Web of Science) were searched from inception to November 2023. Protocol was registered in PROSPERO under the identifier CRD42023476603. A total of twenty-two studies, including four randomized-controlled trials and eighteen open-label trials were included. All studies reported alleviation of anhedonia symptoms following ketamine or esketamine administration, regardless of the number of infusions. Several important limitations were included, first and foremost low number of placebo-controlled randomized-controlled trials. This review indicates a potential anti-anhedonic effect of ketamine in patients with depression. Several trials used neuroimaging techniques which confirm ketamine's effect on functional connectivity correlating with the improvement in anhedonia. Despite considerable variations in methodology and the specific brain regions investigated, these studies collectively point towards ketamine's neuroplastic effects in mitigating anhedonia.
PubMed: 38917771
DOI: 10.1016/j.euroneuro.2024.04.014 -
PsyCh Journal May 2024
PubMed: 38692578
DOI: 10.1002/pchj.767 -
Antioxidants (Basel, Switzerland) Mar 2024The aging of the global population has increased the prevalence of neurodegenerative conditions. (BM), an herb with active compounds, such as bacosides A and B,... (Review)
Review
Investigating the Neuroprotective and Cognitive-Enhancing Effects of : A Systematic Review Focused on Inflammation, Oxidative Stress, Mitochondrial Dysfunction, and Apoptosis.
The aging of the global population has increased the prevalence of neurodegenerative conditions. (BM), an herb with active compounds, such as bacosides A and B, betulinic acid, loliolide, asiatic acid, and quercetin, demonstrates the potential for brain health. Limited research has been conducted on the therapeutic applications of BM in neurodegenerative conditions. This systematic review aims to project BM's beneficial role in brain disorders. BM has anti-apoptotic and antioxidant actions and can repair damaged neurons, stimulate kinase activity, restore synaptic function, improve nerve transmission, and increase neuroprotection. The included twenty-two clinical trials demonstrated that BM can reduce Nuclear Factor-κB phosphorylation, improve emotional function, cognitive functions, anhedonia, hyperactivity, sleep routine, depression, attention deficit, learning problems, memory retention, impulsivity, and psychiatric problems. Moreover, BM can reduce the levels of pro-inflammatory biomarkers and oxidative stress. Here, we highlight that BM provides notable therapeutic benefits and can serve as a complementary approach for the care of patients with neurodegenerative conditions associated with brain disorders. This review adds to the growing interest in natural products and their potential therapeutic applications by improving our understanding of the mechanisms underlying cognitive function and neurodegeneration and informing the development of new therapeutic strategies for neurodegenerative diseases.
PubMed: 38671841
DOI: 10.3390/antiox13040393 -
Journal of Affective Disorders Jul 2024Major depressive disorder (MDD) is a heterogeneous group of mood disorders. A prominent symptom domain is anhedonia narrowly defined as a loss of interest and ability to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Major depressive disorder (MDD) is a heterogeneous group of mood disorders. A prominent symptom domain is anhedonia narrowly defined as a loss of interest and ability to experience pleasure. Anhedonia is associated with depressive symptom severity, MDD prognosis, and suicidality. We perform a systematic review and meta-analysis of extant literature investigating the effects of anhedonia on health-related quality of life (HRQoL) and functional outcomes in persons with MDD.
METHODS
A literature search was conducted on PubMed, OVID databases, and SCOPUS for published articles from inception to November 2023, reporting on anhedonia and patient-reported outcomes in persons with MDD. The reported correlation coefficients between anhedonia and self-reported measures of both HRQoL and functional outcomes were pooled using a random effects model.
RESULTS
We identified 20 studies that investigated anhedonia with HRQoL and/or functional outcomes in MDD. Anhedonia as measured by the Snaith-Hamilton Pleasure Scale (SHAPS) scores had a statistically significant correlation with patient-reported HRQoL (r = -0.41 [95 % CI = -0.60, -0.18]) and functional impairment (r = 0.39 [95 % CI = 0.22, 0.54]).
LIMITATIONS
These preliminary results primarily investigate correlations with consummatory anhedonia and do not distinguish differences in anticipatory anhedonia, reward valuation or reward learning; therefore, these results require replication.
CONCLUSIONS
Persons with MDD experiencing symptoms of anhedonia are more likely to have worse prognosis including physical, psychological, and social functioning deficits. Anhedonia serves as an important predictor and target for future therapeutic and preventative tools in persons with MDD.
Topics: Humans; Anhedonia; Depressive Disorder, Major; Quality of Life
PubMed: 38657767
DOI: 10.1016/j.jad.2024.04.086 -
Trauma, Violence & Abuse Mar 2024High rates of nonresponse to evidence-based treatment for posttraumatic stress disorder (PTSD) have fueled the search for improved intervention. Evidence suggests that... (Review)
Review
High rates of nonresponse to evidence-based treatment for posttraumatic stress disorder (PTSD) have fueled the search for improved intervention. Evidence suggests that improvements in dispositional mindfulness (i.e., tendency to attend to the present with nonjudgment and nonreactivity) may help reduce PTSD symptoms. While some research suggests that transdiagnostic mindfulness-based interventions particularly target avoidance symptoms, the association between dispositional mindfulness and avoidance has yet to be systematically examined. To address this gap, we examined peer-reviewed studies that reported quantitative associations between avoidance and dispositional mindfulness among trauma-exposed adults, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2009 guidelines. Sixteen studies were identified for final review from PsycINFO and PubMed databases. Results suggest that mindfulness has a weak relationship with effortful avoidance. This weak relationship may be obscured in studies where effortful avoidance is measured among other symptoms (e.g., anhedonia). Mindfulness appeared to have stronger associations with symptoms of hyperarousal and negative alterations in cognition and mood. An important clinical implication is that high effortful avoidance may manifest among patients who report strong mindfulness skills. It may be helpful for clinicians to carefully assess how mindfulness is being used to cope.
PubMed: 38523454
DOI: 10.1177/15248380231221278 -
CNS Neuroscience & Therapeutics Mar 2024Noninvasive brain stimulation (NIBS) techniques are a promising tool for treating the negative symptoms of schizophrenia. Growing evidence suggests that different... (Meta-Analysis)
Meta-Analysis
Is it more effective for anhedonia and avolition? A systematic review and meta-analysis of non-invasive brain stimulation interventions for negative symptoms in schizophrenia.
BACKGROUND
Noninvasive brain stimulation (NIBS) techniques are a promising tool for treating the negative symptoms of schizophrenia. Growing evidence suggests that different dimensions of negative symptoms have partly distinct underlying pathophysiological mechanisms. Previous randomized controlled trials (RCTs) have shown inconsistent impacts of NIBS across dimensions.
OBJECTIVE
This systematic review and meta-analysis evaluated the effects of NIBS on general negative symptoms, and on specific domains, including blunted affect, alogia, asociality, anhedonia, and avolition.
DATA SOURCES
PubMed, Web of Science, Embase, Cochrane CENTRAL, PsycINFO, OpenGrey, and Clinicaltrials.gov from the first date available to October, 2023.
RESULTS
Among 1049 studies, we identified eight high-quality RCTs. NIBS significantly affects general negative symptoms (SMD = -0.54, 95% CI [-0.88, -0.21]) and all five domains (SMD = -0.32 to -0.63). Among dimensions, better effects have been shown for improvement of avolition (SMD = -0.47, 95% CI [-0.81, -0.13]) and anhedonia (SMD = -0.63, 95% CI [-0.98, -0.28]). Subgroup analyses of studies that applied once daily stimulation or >10 sessions showed significantly reduced negative symptom severity.
CONCLUSION
NIBS exerts distinct effects across multiple dimensions of negative symptom, with treatment effects related to stimulation frequency and total sessions. These results need to be confirmed in dedicated studies.
Topics: Humans; Anhedonia; Brain; PubMed; Schizophrenia; Electric Stimulation Therapy
PubMed: 38432851
DOI: 10.1111/cns.14645 -
Frontiers in Behavioral Neuroscience 2023Cannabis is one of the most widely used psychoactive substances globally. Cannabis use can be associated with alterations of reward processing, including affective... (Review)
Review
RATIONALE
Cannabis is one of the most widely used psychoactive substances globally. Cannabis use can be associated with alterations of reward processing, including affective flattening, apathy, anhedonia, and lower sensitivity to natural rewards in conjunction with higher sensitivity to cannabis-related rewards. Such alterations have been posited to be driven by changes in underlying brain reward pathways, as per prominent neuroscientific theories of addiction. Functional neuroimaging (fMRI) studies have examined brain reward function in cannabis users via the monetary incentive delay (MID) fMRI task; however, this evidence is yet to be systematically synthesised.
OBJECTIVES
We aimed to systematically integrate the evidence on brain reward function in cannabis users examined by the MID fMRI task; and in relation to metrics of cannabis exposure (e.g., dosage, frequency) and other behavioural variables.
METHOD
We pre-registered the review in PROSPERO and reported it using PRISMA guidelines. Literature searches were conducted in PsycINFO, PubMed, Medline, CINAHL, and Scopus.
RESULTS
Nine studies were included, comprising 534 people with mean ages 16-to-28 years, of which 255 were people who use cannabis daily or almost daily, and 279 were controls. The fMRI literature to date led to largely non-significant group differences. A few studies reported group differences in the ventral striatum while participants anticipated rewards and losses; and in the caudate while participants received neutral outcomes. A few studies examined correlations between brain function and withdrawal, dosage, and age of onset; and reported inconsistent findings.
CONCLUSIONS
There is emerging but inconsistent evidence of altered brain reward function in cannabis users examined with the MID fMRI task. Future fMRI studies are required to confirm if the brain reward system is altered in vulnerable cannabis users who experience a Cannabis Use Disorder, as postulated by prominent neuroscientific theories of addiction.
PubMed: 38379938
DOI: 10.3389/fnbeh.2023.1323609 -
Translational Psychiatry Jan 2024The sucrose preference test is a popular test for anhedonia in the chronic unpredictable stress model of depression. Yet, the test does not always produce consistent... (Meta-Analysis)
Meta-Analysis
Reliability of sucrose preference testing following short or no food and water deprivation-a Systematic Review and Meta-Analysis of rat models of chronic unpredictable stress.
The sucrose preference test is a popular test for anhedonia in the chronic unpredictable stress model of depression. Yet, the test does not always produce consistent results. Long food and water deprivation before the test, while often implemented, confounds the results by introducing unwanted drives in the form of hunger and thirst. We assessed the reliability of the test when only short or no fasting was used. We searched PubMed, Embase, and Web of Science for studies in rats exposed to chronic unpredictable stress that used no more than 6 h of food and/or water deprivation before the test. Sweet consumptions, for stressed and control/antidepressant-treated animals, in 132 studies were pooled using random effects models. We found a decrease in sweet consumption in stressed rats, compared to controls, that was halved when a non-caloric sweetener was used and significantly reduced when sucrose consumption was corrected for body weight. What is more, the length of food and water deprivation was found to confound the effect. The effect was reversed when the stressed rats were treated with antidepressants. Methodological strategies meant to control for recognized sources of bias when conducting the test were often missing, and so was a clear and complete report of essential study information. Our results indicate that not only is food and water deprivation before the test unnecessary, but not recommended. Even in absence of long fasting, we found evidence of an additional effect on sweet consumption that is unrelated to anhedonia. Without properly controlling for non-hedonic drivers of consumption, the test is unreliable as a proxy measure of anhedonia. Strengthening the methodological rigor and addressing the confounding effect of metabolic factors in the sucrose preference test prevents misleading conclusions that harm the translatability of the associated research and perpetuates the use of animals for little gain.
Topics: Animals; Rats; Anhedonia; Food; Reproducibility of Results; Stress, Psychological; Sucrose; Water Deprivation
PubMed: 38242881
DOI: 10.1038/s41398-024-02742-0 -
PsyCh Journal Apr 2024Anhedonia is a transdiagnostic symptom found in patients with schizophrenia and depression. Current pharmacological interventions for anhedonia are unsatisfactory in a... (Meta-Analysis)
Meta-Analysis Review
Anhedonia is a transdiagnostic symptom found in patients with schizophrenia and depression. Current pharmacological interventions for anhedonia are unsatisfactory in a considerable proportion of patients. There has been growing interest in applying noninvasive brain stimulation (NIBS) to patients with anhedonia. However, evidence for the efficacy of NIBS for anhedonia remain inconsistent. This study systematically identified all studies that measured anhedonia and applied NIBS in patients with schizophrenia or depression. We conducted a search using the various databases in English (PubMed, EBSCOHost (PsycInfo/PsycArticles), Web of Science) and Chinese (China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform) languages, and reviewed original research articles on NIBS published from January 1989 to July 2023. Our search had identified 15 articles for quantitative synthesis, with three concerning schizophrenia samples, 11 concerning samples with depression, and one concerning both clinical samples. We conducted a meta-analysis based on the 15 included studies, and the results suggested that NIBS could improve anhedonia symptoms in schizophrenia patients and patients with depression, with a medium-to-large effect size. Our findings are preliminary, given the limited number of included studies. Future NIBS research should measure anhedonia as a primary outcome and should recruit transdiagnostic samples.
Topics: Humans; Schizophrenia; Anhedonia; Depression; Brain; China
PubMed: 38151800
DOI: 10.1002/pchj.723