The processing of rewards and losses are crucial to everyday functioning. Considerable interest has been attached to investigating the anticipation and outcome phases of reward and loss processing, ...but results to date have been inconsistent. It is unclear if anticipation and outcome of a reward or loss recruit similar or distinct brain regions. In particular, while the striatum has widely been found to be active when anticipating a reward, whether it activates in response to the anticipation of losses as well remains ambiguous. Furthermore, concerning the orbitofrontal/ventromedial prefrontal regions, activation is often observed during reward receipt. However, it is unclear if this area is active during reward anticipation as well. We ran an Activation Likelihood Estimation meta‐analysis of 50 fMRI studies, which used the Monetary Incentive Delay Task (MIDT), to identify which brain regions are implicated in the anticipation of rewards, anticipation of losses, and the receipt of reward. Anticipating rewards and losses recruits overlapping areas including the striatum, insula, amygdala and thalamus, suggesting that a generalised neural system initiates motivational processes independent of valence. The orbitofrontal/ventromedial prefrontal regions were recruited only during the reward outcome, likely representing the value of the reward received. Our findings help to clarify the neural substrates of the different phases of reward and loss processing, and advance neurobiological models of these processes.
Abstract The past few decades have seen a marked change in the composition of commonly smoked cannabis. These changes primarily involve an increase of the psychoactive compound ∆9 ...-tetrahydrocannabinol (THC) and a decrease of the potentially therapeutic compound cannabidiol (CBD). This altered composition of cannabis may be linked to persistent neuroanatomic alterations typically seen in regular cannabis users. In this review, we summarize recent findings from human structural neuroimaging investigations. We examine whether neuroanatomic alterations are 1) consistently observed in samples of regular cannabis users, particularly in cannabinoid receptor–high areas, which are vulnerable to the effects of high circulating levels of THC, and 2) associated either with greater levels of cannabis use (e.g., higher dosage, longer duration, and earlier age of onset) or with distinct cannabinoid compounds (i.e., THC and CBD). Across the 31 studies selected for inclusion in this review, neuroanatomic alterations emerged across regions that are high in cannabinoid receptors (i.e., hippocampus, prefrontal cortex, amygdala, cerebellum). Greater dose and earlier age of onset were associated with these alterations. Preliminary evidence shows that THC exacerbates, whereas CBD protects from, such harmful effects. Methodologic differences in the quantification of levels of cannabis use prevent accurate assessment of cannabis exposure and direct comparison of findings across studies. Consequently, the field lacks large “consortium-style” data sets that can be used to develop reliable neurobiological models of cannabis-related harm, recovery, and protection. To move the field forward, we encourage a coordinated approach and suggest the urgent development of consensus-based guidelines to accurately and comprehensively quantify cannabis use and exposure in human studies.
Global concern about problematic usage of the internet (PUI), and its public health and societal costs, continues to grow, sharpened in focus under the privations of the COVID-19 pandemic. This ...narrative review reports the expert opinions of members of the largest international network of researchers on PUI in the framework of the European Cooperation in Science and Technology (COST) Action (CA 16207), on the scientific progress made and the critical knowledge gaps remaining to be filled as the term of the Action reaches its conclusion.
A key advance has been achieving consensus on the clinical definition of various forms of PUI. Based on the overarching public health principles of protecting individuals and the public from harm and promoting the highest attainable standard of health, the World Health Organisation has introduced several new structured diagnoses into the ICD-11, including gambling disorder, gaming disorder, compulsive sexual behaviour disorder, and other unspecified or specified disorders due to addictive behaviours, alongside naming online activity as a diagnostic specifier. These definitions provide for the first time a sound platform for developing systematic networked research into various forms of PUI at global scale. Progress has also been made in areas such as refining and simplifying some of the available assessment instruments, clarifying the underpinning brain-based and social determinants, and building more empirically based etiological models, as a basis for therapeutic intervention, alongside public engagement initiatives.
However, important gaps in our knowledge remain to be tackled. Principal among these include a better understanding of the course and evolution of the PUI-related problems, across different age groups, genders and other specific vulnerable groups, reliable methods for early identification of individuals at risk (before PUI becomes disordered), efficacious preventative and therapeutic interventions and ethical health and social policy changes that adequately safeguard human digital rights. The paper concludes with recommendations for achievable research goals, based on longitudinal analysis of a large multinational cohort co-designed with public stakeholders.
•Research advances in Problematic Use of the Internet (PUI) and key evidence gaps.•Narrative review by experts and public stakeholders from the European COST Action.•PUI is growing; Vulnerable groups include children and young people.•Reliable methods for early detection, recognition and prevention are needed.•Longitudinal study of PUI, health and wellbeing will inform effective policy change.
Aerobic exercise (AE) has been widely praised for its potential benefits to cognition and overall brain and mental health. In particular, AE has a potent impact on promoting the function of the ...hippocampus and stimulating neuroplasticity. As the evidence-base rapidly builds, and given most of the supporting work can be readily translated from animal models to humans, the potential for AE to be applied as a therapeutic or adjunctive intervention for a range of human conditions appears ever more promising. Notably, many psychiatric and neurological disorders have been associated with hippocampal dysfunction, which may underlie the expression of certain symptoms common to these disorders, including (aspects of) cognitive dysfunction. Augmenting existing treatment approaches using AE based interventions may promote hippocampal function and alleviate cognitive deficits in various psychiatric disorders that currently remain untreated. Incorporating non-pharmacological interventions into clinical treatment may also have a number of other benefits to patient well being, such as limiting the risk of adverse side effects. This review incorporates both animal and human literature to comprehensively detail how AE is associated with cognitive enhancements and stimulates a cascade of neuroplastic mechanisms that support improvements in hippocampal functioning. Using the examples of schizophrenia and major depressive disorder, the utility and implementation of an AE intervention to the clinical domain will be proposed, aimed to reduce cognitive deficits in these, and related disorders.
Although lower brain volume has been routinely observed in individuals with substance dependence compared with nondependent control subjects, the brain regions exhibiting lower volume have not been ...consistent across studies. In addition, it is not clear whether a common set of regions are involved in substance dependence regardless of the substance used or whether some brain volume effects are substance specific. Resolution of these issues may contribute to the identification of clinically relevant imaging biomarkers. Using pooled data from 14 countries, the authors sought to identify general and substance-specific associations between dependence and regional brain volumes.
Brain structure was examined in a mega-analysis of previously published data pooled from 23 laboratories, including 3,240 individuals, 2,140 of whom had substance dependence on one of five substances: alcohol, nicotine, cocaine, methamphetamine, or cannabis. Subcortical volume and cortical thickness in regions defined by FreeSurfer were compared with nondependent control subjects when all sampled substance categories were combined, as well as separately, while controlling for age, sex, imaging site, and total intracranial volume. Because of extensive associations with alcohol dependence, a secondary contrast was also performed for dependence on all substances except alcohol. An optimized split-half strategy was used to assess the reliability of the findings.
Lower volume or thickness was observed in many brain regions in individuals with substance dependence. The greatest effects were associated with alcohol use disorder. A set of affected regions related to dependence in general, regardless of the substance, included the insula and the medial orbitofrontal cortex. Furthermore, a support vector machine multivariate classification of regional brain volumes successfully classified individuals with substance dependence on alcohol or nicotine relative to nondependent control subjects.
The results indicate that dependence on a range of different substances shares a common neural substrate and that differential patterns of regional volume could serve as useful biomarkers of dependence on alcohol and nicotine.
Background and aims
Following the recognition of ‘internet gaming disorder’ (IGD) as a condition requiring further study by the DSM‐5, ‘gaming disorder’ (GD) was officially included as a diagnostic ...entity by the World Health Organization (WHO) in the 11th revision of the International Classification of Diseases (ICD‐11). However, the proposed diagnostic criteria for gaming disorder remain the subject of debate, and there has been no systematic attempt to integrate the views of different groups of experts. To achieve a more systematic agreement on this new disorder, this study employed the Delphi expert consensus method to obtain expert agreement on the diagnostic validity, clinical utility and prognostic value of the DSM‐5 criteria and ICD‐11 clinical guidelines for GD.
Methods
A total of 29 international experts with clinical and/or research experience in GD completed three iterative rounds of a Delphi survey. Experts rated proposed criteria in progressive rounds until a pre‐determined level of agreement was achieved.
Results
For DSM‐5 IGD criteria, there was an agreement both that a subset had high diagnostic validity, clinical utility and prognostic value and that some (e.g. tolerance, deception) had low diagnostic validity, clinical utility and prognostic value. Crucially, some DSM‐5 criteria (e.g. escapism/mood regulation, tolerance) were regarded as incapable of distinguishing between problematic and non‐problematic gaming. In contrast, ICD‐11 diagnostic guidelines for GD (except for the criterion relating to diminished non‐gaming interests) were judged as presenting high diagnostic validity, clinical utility and prognostic value.
Conclusions
This Delphi survey provides a foundation for identifying the most diagnostically valid and clinically useful criteria for GD. There was expert agreement that some DSM‐5 criteria were not clinically relevant and may pathologize non‐problematic patterns of gaming, whereas ICD‐11 diagnostic guidelines are likely to diagnose GD adequately and avoid pathologizing.
Error processing and inhibitory control enable the adjustment of behaviors to meet task demands. Functional magnetic resonance imaging studies report brain activation abnormalities in patients with ...obsessive-compulsive disorder (OCD) during both processes. However, conclusions are limited by inconsistencies in the literature and small sample sizes. Therefore, the aim here was to perform a meta-analysis of the existing literature using unthresholded statistical maps from previous studies.
A voxelwise seed-based d mapping meta-analysis was performed using t-maps from studies comparing patients with OCD and healthy control subjects (HCs) during error processing and inhibitory control. For the error processing analysis, 239 patients with OCD (120 male; 79 medicated) and 229 HCs (129 male) were included, while the inhibitory control analysis included 245 patients with OCD (120 male; 91 medicated) and 239 HCs (135 male).
Patients with OCD, relative to HCs, showed longer inhibitory control reaction time (standardized mean difference = 0.20, p = .03, 95% confidence interval = 0.016, 0.393) and more inhibitory control errors (standardized mean difference = 0.22, p = .02, 95% confidence interval = 0.039, 0.399). In the brain, patients showed hyperactivation in the bilateral dorsal anterior cingulate cortex, supplementary motor area, and pre-supplementary motor area as well as right anterior insula/frontal operculum and anterior lateral prefrontal cortex during error processing but showed hypoactivation during inhibitory control in the rostral and ventral anterior cingulate cortices and bilateral thalamus/caudate, as well as the right anterior insula/frontal operculum, supramarginal gyrus, and medial orbitofrontal cortex (all seed-based d mapping z value >2, p < .001).
A hyperactive error processing mechanism in conjunction with impairments in implementing inhibitory control may underlie deficits in stopping unwanted compulsive behaviors in the disorder.
While lifestyle medicine can be highly effective for treating a range of mental illnesses these approaches are grossly underutilised and have not been systematically implemented into health care ...systems. Understanding the acceptability of lifestyle medicine is a critical first step to remediate this. This study evaluated the acceptability of lifestyle medicine relative to pharmacotherapy and psychotherapy, and explore perspectives of people with and without lived experience of mental illness.
Six hundred and forty-nine adult Australian residents (62.6% female; 53.6% with a lifetime diagnosis of mental illness) completed an online survey based on the Theoretical Framework of Acceptability assessing the acceptability of lifestyle medicine, pharmacotherapy and psychotherapy for treating mental illness.
Most participants felt positive about lifestyle medicine (76.9%) and felt that such approaches aligned with their personal values (74.9%). They understood how lifestyle medicine worked (86.4%) and believed it would be effective (69.6%). Lived experience of mental illness was associated with greater perceived burden and lower self-efficacy to engage in lifestyle medicine activities (both p < 0.001). While there was a clear preference for psychotherapy and lifestyle medicine over pharmacotherapy, pharmacotherapy was perceived as least effortful (p < .001) and participants were least confident in their ability to engage in lifestyle medicine (p < 0.05).
The findings indicate strong acceptability of lifestyle medicine for mental illness, a preference for non-pharmacological treatment approaches, and an understanding of the challenges associated with making long-term healthy lifestyle modifications amongst people who have lived experience of mental illness.
Abstract Background While there is evidence to suggest that major depressive disorder (MDD) is associated with structural brain abnormalities, the precise nature of these abnormalities remains ...unclear. Aims To review recent structural magnetic resonance imaging (MRI) research findings in MDD while considering the potential influence of key clinical and demographic variables. Method A selective review of all T1-weighted structural MRI studies published between 2000 and 2007 in adult samples of MDD patients. Results Volumetric reductions of the hippocampus, basal ganglia and OFC and SGPFC are consistently found in MDD patients, with more persistent forms of MDD (e.g., multiple episodes or repeated relapses, longer illness duration) being associated with greater impact on regional brain volumes. Gender, medication, stage of illness, and family history all affect the nature of the findings in a regionally specific manner. Limitations Overall, differences between the samples in factors such as illness severity, medication, gender and family history of mental illness makes difficult to identify their confounding effects on the observed neuroanatomical changes. Also, the tracing protocols used for particular brain regions were different amongst the reviewed studies, making difficult to compare their findings. Conclusions The data support the notion that MDD involves pathological alterations of limbic and cortical structures, and that they are generally more apparent in patients with more severe or persistent forms of the illness.
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