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Journal of Psychiatric Research Dec 2023Transcranial alternating current stimulation (tACS) is an innovative noninvasive technique in brain stimulation that involves applying a low-intensity electrical current... (Review)
Review
BACKGROUND
Transcranial alternating current stimulation (tACS) is an innovative noninvasive technique in brain stimulation that involves applying a low-intensity electrical current to the scalp. And increasing evidence has revealed its potential in schizophrenia treatment.
OBJECTIVE
This systematic review aimed to evaluate the efficacy of tACS as a novel neurostimulation technique for improving cognitive impairment and alleviating psychotic symptoms in schizophrenia. Additionally, this review attempted to explore the impact of stimulation parameters on the effectiveness of tACS treatment.
METHODS
A systematic literature search was conducted across five databases, including Web of Science, Embase, PubMed, CENTRAL, and PsycINFO, to identify studies investigating the use of tACS in schizophrenia. Only studies that involved the experimental use of tACS in patients with schizophrenia were included in this review.
RESULTS
Nineteen studies were included in this review. The most frequently used current intensities were 2 mA and 1 mA, and the most commonly used frequencies were alpha (10 Hz), theta (4.5 Hz and 6 Hz), and gamma (40 Hz). Some studies showed that tACS may have a potential therapeutic effect by improving cognitive functions in various cognitive domains and/or ameliorating negative symptoms, hallucinations, and delusions in patients with schizophrenia, while others showed no significant change. These studies also implicated that tACS treatment is safe and well tolerated.
CONCLUSIONS
Overall, this systematic review suggests that tACS has promise as a novel, effective, and adjunctive treatment approach for treating schizophrenia. Future research is needed to determine the optimal parameters of tACS for treating this complex disorder.
Topics: Humans; Schizophrenia; Transcranial Direct Current Stimulation; Hallucinations; Cognition
PubMed: 37897837
DOI: 10.1016/j.jpsychires.2023.10.021 -
Psychological Medicine Oct 2022Psychotic symptoms, that we defined as delusions or hallucinations, are common in bipolar disorders (BD). This systematic review and meta-analysis aims to synthesise the... (Meta-Analysis)
Meta-Analysis Review
Psychotic symptoms, that we defined as delusions or hallucinations, are common in bipolar disorders (BD). This systematic review and meta-analysis aims to synthesise the literature on both lifetime and point prevalence rates of psychotic symptoms across different BD subtypes, including both BD type I (BDI) and BD type II (BDII). We performed a systematic search of Medline, PsycINFO, Embase and Cochrane Library until 5 August 2021. Fifty-four studies ( = 23 461) of adults with BD met the predefined inclusion criteria for evaluating lifetime prevalence, and 24 studies ( = 6480) for evaluating point prevalence. Quality assessment and assessment of publication bias were performed. Prevalence rates were calculated using random effects meta-analysis, here expressed as percentages with a 95% confidence interval (CI). In studies of at least moderate quality, the pooled lifetime prevalence of psychotic symptoms in BDI was 63% (95% CI 57.5-68) and 22% (95% CI 14-33) in BDII. For BDI inpatients, the pooled lifetime prevalence was 71% (95% CI 61-79). There were no studies of community samples or inpatient BDII. The pooled point prevalence of psychotic symptoms in BDI was 54% (95 CI 41-67). The point prevalence was 57% (95% CI 47-66) in manic episodes and 13% (95% CI 7-23.5) in depressive episodes. There were not enough studies in BDII, BDI depression, mixed episodes and outpatient BDI. The pooled prevalence of psychotic symptoms in BDI may be higher than previously reported. More studies are needed for depressive and mixed episodes and community samples.Prospero registration number: CRD 42017052706.
Topics: Adult; Humans; Bipolar Disorder; Prevalence; Psychotic Disorders; Hallucinations; Mania
PubMed: 36016504
DOI: 10.1017/S003329172200201X -
Psychopharmacology May 2024Synthetic cathinones (SC), commonly referred to as "bath salts", are stimulants resembling the natural alkaloid cathinone found in the khat plant. These substances have... (Meta-Analysis)
Meta-Analysis Review
RATIONALE
Synthetic cathinones (SC), commonly referred to as "bath salts", are stimulants resembling the natural alkaloid cathinone found in the khat plant. These substances have the potential to induce serious health risks such as hallucinations, delusions, paranoia and agitation which can lead to substance-induced psychotic disorders. Despite growing concerns, there is a limited understanding of the association between SC consumption and the devolvement of such psychopathologies.
METHODS
We conducted a systematic review to investigate the frequency of substance-induced psychotic disorder (SIPD) and associated conditions in humans following synthetic cathinone consumption. We qualitatively and quantitatively analyzed SC exposure cases.
RESULTS
A total of 32 studies were included, with a diverse range of demographics, synthetic cathinone types, and consumption patterns. The proportion of individuals developing psychotic symptoms was reported at 0.380 (Random-effects model, 95% CI 0.289 - 0.475). Additionally, the significant heterogeneity in diagnostic approaches limited our ability to provide a precise estimate of prevalence.
CONCLUSIONS
Synthetic cathinone consumption is associated with the risk of developing psychotic symptoms as indicated by the prevalence of hallucinations and/or delusions. Due to the lack of information on classifying factors, particularly duration of symptoms, we are unable to conclude synthetic cathinone-induced psychosis. Further research is warranted to elucidate the underlying mechanism linking synthetic cathinone consumption and psychosis. This review underscores the urgency of addressing the growing health risks posed by synthetic cathinone use. Additionally, it highlights the necessity of proper quantification of psychotic symptoms through scales and reporting of classification criteria to accurately diagnose SIPD.
Topics: Humans; Synthetic Cathinone; Central Nervous System Stimulants; Substance-Related Disorders; Psychoses, Substance-Induced; Hallucinations
PubMed: 38446172
DOI: 10.1007/s00213-024-06569-x -
Children (Basel, Switzerland) Jan 2021This review aims to evaluate the effectiveness of virtual reality-based interventions (VR-based interventions) on cognitive deficits in children with attention deficit... (Review)
Review
This review aims to evaluate the effectiveness of virtual reality-based interventions (VR-based interventions) on cognitive deficits in children with attention deficit hyperactivity disorder (ADHD). A systematic review and meta-analysis were performed according to the PRISMA statement and the Cochrane Handbook guidelines for conducting meta-analyses. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the quality of the evidence. Clinical trials published up to 29 October 2020, were included. The meta-analysis included four studies, with a population of 125 participants with ADHD. The magnitude of the effect was large for omissions (SMD = -1.38; = 0.009), correct hits (SMD = -1.50; = 0.004), and perceptual sensitivity (SMD = -1.07; = 0.01); and moderate for commissions (SMD = -0.62; = 0.002) and reaction time (SMD = -0.67; = 0.03). The use of VR-based interventions for cognitive rehabilitation in children with ADHD is limited. The results showed that VR-based interventions are more effective in improving sustained attention. Improvements were observed in attentional vigilance measures, increasing the number of correct responses and decreasing the number of errors of omission. No improvements were observed in impulsivity responses.
PubMed: 33494272
DOI: 10.3390/children8020070 -
Journal of Behavior Therapy and... Jun 2021Voice-hearing exists on a continuum and research studies have utilised experimental paradigms in an attempt to induce unusual auditory experiences in clinical and... (Review)
Review
BACKGROUND AND OBJECTIVES
Voice-hearing exists on a continuum and research studies have utilised experimental paradigms in an attempt to induce unusual auditory experiences in clinical and non-clinical samples. The aim of the current review was to systematically identify, review and appraise voice-hearing induction paradigms in order to guide researchers.
METHODS
Five databases were searched for studies in which an experimental manipulation was used with the aim of inducing an auditory experience akin to voice-hearing. Papers were assessed for quality and the voice-hearing paradigms critically appraised.
RESULTS
Forty-nine studies, included in 41 papers, were reviewed. Studies were organised into five groups based on the type of voice-hearing paradigm used: sensory deprivation/limitation; hallucination suggestion; combined suggestion and ambiguous stimulus; signal detection and voice detection tasks; and auditory discrimination/transformation. Signal and voice detection tasks were found to be the most robust paradigms. The quality of paradigms was assessed, and their strengths and limitations evaluated, including evidence in relation to their utility, ecological validity and usability.
LIMITATIONS
The current review excluded case studies, grey literature and studies which were not written in the English language, and as such voice-hearing paradigms may have been missed.
CONCLUSIONS
Voice-hearing paradigms vary in their ecological validity and experimental robustness. A challenge for future research is to develop a paradigm in which internally generated material can be attributed externally in a way that more closely represents inner speech and the experience of voice-hearing.
Topics: Auditory Perception; Hallucinations; Humans; Voice
PubMed: 33348277
DOI: 10.1016/j.jbtep.2020.101635 -
Annals of Physical and Rehabilitation... Jul 2021Although previous narrative reviews have highlighted a potential association between visuospatial neglect (VSN) and balance disorders, to what extent different areas of... (Review)
Review
BACKGROUND
Although previous narrative reviews have highlighted a potential association between visuospatial neglect (VSN) and balance disorders, to what extent different areas of balance and mobility could be affected is still unclear.
OBJECTIVES
This systematic review updates previous literature findings and systematically reviews sitting balance, standing balance and mobility outcomes.
METHODS
PubMed, Web of Science, ScienceDirect, Naric-Rehabdata, PEDro and the Cochrane Trials Library were systematically searched. Methodological quality was assessed by the National Heart, Lung, and Blood Institute Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. The association between VSN and sitting balance, standing balance and mobility (walking, stair climbing/descending and transfers) was investigated.
RESULTS
In total, 48 studies were included (4595 stroke survivors): at least 1319 (29%) showed symptoms of VSN. VSN was associated with less independence during sitting, with an asymmetric posture toward the affected body side. For standing balance, we revealed a significant negative association between VSN and mediolateral stability and weight shifting, whereas only activities of daily living-related VSN was associated with weight-bearing asymmetry during static stance. While walking, patients with VSN laterally deviated from their path. Results were inconclusive regarding other aspects of mobility. The association between VSN and balance/mobility seemed to decrease over time.
CONCLUSIONS
Despite great heterogeneity in results, this study suggests that stroke survivors with VSN show specific deviations in posture and movement in the mediolateral direction. Although the association between VSN and balance/mobility has been extensively investigated, explanatory studies evaluating underlying mechanisms of the frequently present association are lacking. Future studies should address this by combining clinical and instrumented assessment of balance and gait performance, preferably longitudinally to investigate the associations over time.
Topics: Activities of Daily Living; Cross-Sectional Studies; Humans; Perceptual Disorders; Postural Balance; Stroke; Stroke Rehabilitation
PubMed: 33152521
DOI: 10.1016/j.rehab.2020.10.003 -
Cannabis and Cannabinoid Research Dec 2023The effects of cannabidiol (CBD) on cognition has been investigated in recent years to determine the therapeutic potential of this cannabinoid for a broad gamut of... (Review)
Review
The effects of cannabidiol (CBD) on cognition has been investigated in recent years to determine the therapeutic potential of this cannabinoid for a broad gamut of medical conditions, including neuropsychiatric disorders. The aim of the present study was to perform a systematic review of studies that analyzed the effects of the acute and chronic administration of CBD on cognition in humans and animals both to assess the cognitive safety of CBD and to determine a beneficial potential of CBD on cognition. The PubMed, Web of Science, PsycINFO, and Scopus databases were searched in December of 2022 for relevant articles using the following combinations of keywords: ("cannabidiol" OR "CBD") AND ("cognition" OR "processing cognitive" OR "memory" OR "language" OR "attention" OR "executive function" OR "social cognition" OR "perceptual motor ability" OR "processing speed"). Fifty-nine articles were included in the present review (36 preclinical and 23 clinical trials). CBD seems not to have any negative effect on cognitive processing in rats. The clinical trials confirmed these findings in humans. One study found that repeated dosing with CBD may improve cognitive in people who use cannabis heavily but not individuals with neuropsychiatric disorders. Considering the context of neuropsychiatric disorders in animal models, CBD seems to reverse the harm caused by the experimental paradigms, such that the performance of these animals becomes similar to that of control animals. The results demonstrate that the chronic and acute administration of CBD seems not to impair cognition in humans without neuropsychiatric disorders. In addition, preclinical studies report promising results regarding the effects of CBD on the cognitive processing of animals. Future double-blind, placebo-controlled, randomized clinical trials with larger, less selective samples, with standardized tests, and using different doses of CBD in outpatients are of particular interest to elucidate the cognitive effects of CBD.
Topics: Humans; Rats; Animals; Cannabidiol; Cognition; Cannabinoids; Hallucinogens; Executive Function; Randomized Controlled Trials as Topic
PubMed: 37792394
DOI: 10.1089/can.2023.0086 -
Harvard Review of PsychiatrySexual hallucinations are little known, yet often extremely burdening, phenomena. In this systematic review, we summarize what is known about their phenomenology,...
Sexual hallucinations are little known, yet often extremely burdening, phenomena. In this systematic review, we summarize what is known about their phenomenology, prevalence, etiopathology, ensuing distress, and treatment options. Sexual hallucinations can be experienced as genital or orgasmic sensations, although other sensory modalities can also be involved. With the notable exception of orgasmic auras in the context of epilepsy, sexual hallucinations tend to be distressing and embarrassing in nature. Our analysis of 79 studies (together describing 390 patients) indicates that sexual hallucinations are more frequent in women than in men, with a sex ratio of 1.4:1, and that they are most prevalent in schizophrenia spectrum disorders, with rates ranging from 1.4% in recently admitted patients to 44% in chronically hospitalized patients. Other underlying conditions include epilepsy, the incubus phenomenon (possibly the most prevalent cause in the general population, associated with sleep paralysis), narcolepsy, and sedative use. As regards the sedative context, we found more medicolegal than purely medical cases, which sadly underlines that not all sexually explicit sensations experienced in anesthesia practice are indeed hallucinations. In the absence of evidence-based treatment protocols for sexual hallucinations, practice-based guidelines tend to focus on the underlying condition. Further research is needed, especially in the fields of substance abuse, posttraumatic stress disorder, and borderline personality disorder, where only anecdotal information on sexual hallucinations is available. Moreover, awareness of sexual hallucinations among health professionals needs to be improved in order to facilitate counseling, diagnosis, and treatment.
Topics: Female; Humans; Male; Borderline Personality Disorder; Epilepsy; Hallucinations; Health Personnel; Hypnotics and Sedatives; Sexual Arousal
PubMed: 38181099
DOI: 10.1097/HRP.0000000000000388 -
JAMA Psychiatry May 2022A substantial increase in the number of trials examining metacognitive training (MCT) for psychosis necessitates an updated examination of the outcomes associated with... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
A substantial increase in the number of trials examining metacognitive training (MCT) for psychosis necessitates an updated examination of the outcomes associated with MCT.
OBJECTIVES
To review the immediate and sustained associations of MCT with proximal (directly targeted) and distal (indirectly influenced) outcomes and assess treatment- and participant-related moderators to identify the potential factors associated with the expected heterogeneity of effect sizes.
DATA SOURCES
Eleven electronic databases were searched from 2007 to June 3, 2021 (alert until September 10, 2021). Reference lists of earlier meta-analyses and included reports were screened.
STUDY SELECTION
Reports examined MCT and included participants with schizophrenia spectrum and related psychotic disorders (1045 reports identified; 281 assessed). There were no age, sex, gender, race and ethnicity, language, or study design restrictions. Two reviewers performed the selection of studies to be analyzed.
DATA EXTRACTION AND SYNTHESIS
The Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline was followed. Data were extracted by 3 reviewers and pooled using random effects models. Hedges g effect sizes were computed. The Mixed-Methods Appraisal tool was used to assess study quality.
MAIN OUTCOMES AND MEASURES
Proximal outcomes were global positive symptoms, delusions, hallucinations, and cognitive biases. Distal outcomes were self-esteem, negative symptoms, quality of life, well-being, and functioning. Immediate and sustained outcomes were examined. Meta-regressions, subgroup, and sensitivity analyses assessed moderators.
RESULTS
This systematic review and meta-analysis included 43 studies (46 reports). Forty reports were synthesized in meta-analysis (N=1816 participants) and 6 reports were included in narrative review. In the studies examined, MCT was associated with positive symptoms (g = 0.50; 95% CI, 0.34-0.67), delusions (g = 0.69; 95% CI, 0.45-0.93), hallucinations (g = 0.26; 95% CI, 0.11-0.40), cognitive biases (g = 0.16; 95% CI, 0.03-0.29), self-esteem (g = 0.17; 95% CI, 0.03-0.31), negative symptoms (g = 0.23; 95% CI, 0.10-0.37), and functioning (g = 0.41; 95% CI, 0.12-0.69). These associations were maintained up to 1 year. The quality of life effect size was nonsignificant (g = 0.20; 95% CI, -0.07 to 0.47); only 1 study assessed well-being. Publication year was associated with moderated hallucinations (β = 0.04; 95% CI, 0.00-0.07). Overall, narrative review results corroborated meta-analytic findings.
CONCLUSIONS AND RELEVANCE
In this meta-analysis, MCT for psychosis was associated with benefits up to 1 year postintervention in several treatment contexts. These findings suggest that MCT may merit integration in treatment guidelines for schizophrenia.
Topics: Hallucinations; Humans; Metacognition; Psychotic Disorders; Quality of Life; Schizophrenia
PubMed: 35320347
DOI: 10.1001/jamapsychiatry.2022.0277 -
Child: Care, Health and Development Nov 2023Children with specific learning disorders (SLD) may have issues in cognitive, motor, and academic skills, affecting their mental health and level of participation in... (Review)
Review
BACKGROUND
Children with specific learning disorders (SLD) may have issues in cognitive, motor, and academic skills, affecting their mental health and level of participation in academic and nonacademic activities at school and in everyday life. Research shows that perceptual-motor (PM) exercises and physical activities can improve the cognitive and motor skills of typically developing children. To use PM exercises as an intervention in clinical practice for children with learning disorders, or to use it in future research, it seems necessary to discuss and summarize the existing documents in this group of children.
OBJECTIVES
We aimed to appraise the extent, and the quality of studies about PM interventions for enhancing cognitive, motor, and academic skills in children with learning disorders.
METHODS
The search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles published between January 2000 and June 2022 were searched in the following scientific databases: PubMed, Medline, Scopus, Web of Science, Cochrane library, Science direct, and Google Scholar. The study eligibility criteria were previously established according to the PICOS model. The Physiotherapy Evidence Database (PEDro) scale was used to assess the methodological quality of the studies, and the Cochrane Collaboration tool (ROB2) was used to assess the risk of bias.
RESULTS
The initial search yielded 2160 studies among which 10 studies were systematically reviewed. The total number of participants was 483 children (intervention: 251; control: 232). Findings showed significant improvements in cognitive skills (n = 7/8) such as working memory, attention, and information processing speed. In addition, studies showed that PM and physical activity interventions could increase academic performance (n = 4/5) and motor skills (n = 5/5) in children with LD. Results regarding the mental health effects of PM exercises (n = 1/3) are few in number and contradicting.
DISCUSSION
PM exercises may positively affect cognitive, motor, and academic skills in children with SLD; However, due to the small number of studies, fair methodological quality, and high risk of bias, caution should be taken when interpreting the results.
Topics: Child; Humans; Exercise; Cognition; Academic Performance; Learning Disabilities; Schools; Motor Skills
PubMed: 36872844
DOI: 10.1111/cch.13111