-
Sleep Medicine Reviews Jun 2023The consumption of caffeine in response to insufficient sleep may impair the onset and maintenance of subsequent sleep. This systematic review and meta-analysis... (Meta-Analysis)
Meta-Analysis Review
The consumption of caffeine in response to insufficient sleep may impair the onset and maintenance of subsequent sleep. This systematic review and meta-analysis investigated the effect of caffeine on the characteristics of night-time sleep, with the intent to identify the time after which caffeine should not be consumed prior to bedtime. A systematic search of the literature was undertaken with 24 studies included in the analysis. Caffeine consumption reduced total sleep time by 45 min and sleep efficiency by 7%, with an increase in sleep onset latency of 9 min and wake after sleep onset of 12 min. Duration (+6.1 min) and proportion (+1.7%) of light sleep (N1) increased with caffeine intake and the duration (-11.4 min) and proportion (-1.4%) of deep sleep (N3 and N4) decreased with caffeine intake. To avoid reductions in total sleep time, coffee (107 mg per 250 mL) should be consumed at least 8.8 h prior to bedtime and a standard serve of pre-workout supplement (217.5 mg) should be consumed at least 13.2 h prior to bedtime. The results of the present study provide evidence-based guidance for the appropriate consumption of caffeine to mitigate the deleterious effects on sleep.
Topics: Humans; Caffeine; Sleep; Polysomnography; Coffee; Sleep Deprivation
PubMed: 36870101
DOI: 10.1016/j.smrv.2023.101764 -
Journal of Affective Disorders Feb 2023Psychedelic therapy shows promise for Major Depressive Disorder, especially when treatment-resistant, as well as life-threatening illness distress. The objective of this... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Psychedelic therapy shows promise for Major Depressive Disorder, especially when treatment-resistant, as well as life-threatening illness distress. The objective of this systematic review, inclusive of meta-analysis, is to examine recent clinical research on the therapeutic effects of classic psychedelics on depressive symptoms.
METHODS
Fourteen psychedelic therapy studies, utilising psilocybin, ayahuasca, or LSD, were systematically reviewed. For the meta-analysis, standardised mean differences were calculated for seven randomised controlled trials.
RESULTS
The systematic review indicated significant short- and long-term reduction of depressive symptoms in all conditions studied after administration of psilocybin, ayahuasca, or LSD, with psychological support. In the meta-analysis, symptom reduction was significantly indicated in three timepoints out of four, including 1-day, 1-week, and 3-5 weeks, supporting the results of the systematic review, with the exception of the 6-8 weeks follow-up point which was less conclusive.
LIMITATIONS
The absence of required data for 2 studies necessitated the less precise use of graphical extraction and imputation. The small sample size in all but one study negatively affected the statistical power. None of the studies had long-term follow-up without also utilising the cross-over method, which did not allow for long-term results to be included in the meta-review.
CONCLUSIONS
This review indicates an association between psychedelic therapy and significant reduction of depressive symptoms at several time points. However, the small number of studies, and low sample sizes, calls for careful interpretation of results. This suggests the need for more randomised clinical trials of psychedelic therapy, with larger and more diverse samples.
Topics: Humans; Hallucinogens; Psilocybin; Lysergic Acid Diethylamide; Depression; Depressive Disorder, Major
PubMed: 36209780
DOI: 10.1016/j.jad.2022.09.168 -
Neuroscience and Biobehavioral Reviews Jun 2020Research into the basic effects and therapeutic applications of psychedelic drugs has grown considerably in recent years. Yet, pressing questions remain regarding the... (Review)
Review
Research into the basic effects and therapeutic applications of psychedelic drugs has grown considerably in recent years. Yet, pressing questions remain regarding the substances' lasting effects. Although individual studies have begun monitoring sustained changes, no study to-date has synthesized this information. Therefore, this systematic review aims to fill this important gap in the literature by synthesizing results from 34 contemporary experimental studies which included classic psychedelics, human subjects, and follow-up latencies of at least two weeks. The bulk of this work was published in the last five years, with psilocybin being the most frequently administered drug. Enduring changes in personality/attitudes, depression, spirituality, anxiety, wellbeing, substance misuse, meditative practices, and mindfulness were documented. Mystical experiences, connectedness, emotional breakthrough, and increased neural entropy were related to these long-term changes in psychological functioning. Finally, with proper screening, preparation, supervision, and integration, limited aversive side effects were noted by study participants. Future researchers should focus on including larger and more diverse samples, lengthier longitudinal designs, stronger control conditions, and standardized dosages.
Topics: Anxiety; Emotions; Hallucinogens; Humans; Pharmaceutical Preparations; Psilocybin
PubMed: 32194129
DOI: 10.1016/j.neubiorev.2020.03.017 -
Nutrients Dec 2022Caffeine (1,3,7-trimethylxanthine) is one of the most widely consumed performance-enhancing substances in sport due to its well-established ergogenic effects. The use of... (Meta-Analysis)
Meta-Analysis Review
Caffeine (1,3,7-trimethylxanthine) is one of the most widely consumed performance-enhancing substances in sport due to its well-established ergogenic effects. The use of caffeine is more common in aerobic-based sports due to the ample evidence endorsing the benefits of caffeine supplementation on endurance exercise. However, most of this evidence was established with cycling trials in the laboratory, while the effects of the acute intake of caffeine on endurance running performance have not been properly reviewed and meta-analyzed. The purpose of this study was to perform a systematic review and meta-analysis of the existing literature on the effects of caffeine intake on endurance running performance. A systematic review of published studies was performed in four different scientific databases (Medline, Scopus, Web of Science, and SportDiscus) up until 5 October 2022 (with no year restriction applied to the search strategy). The selected studies were crossover experimental trials in which the ingestion of caffeine was compared to a placebo situation in a single- or double-blind randomized manner. The effect of caffeine on endurance running was measured by time to exhaustion or time trials. We assessed the methodological quality of each study using Cochrane’s risk-of-bias (RoB 2) tool. A subsequent meta-analysis was performed using the random effects model to calculate the standardized mean difference (SMD) estimated by Hedges’ g and 95% confidence intervals (CI). Results: A total of 21 randomized controlled trials were included in the analysis, with caffeine doses ranging between 3 and 9 mg/kg. A total of 21 studies were included in the systematic review, with a total sample of 254 participants (220 men, 19 women and 15 participants with no information about gender; 167 were categorized as recreational and 87 were categorized as trained runners.). The overall methodological quality of studies was rated as unclear-to-low risk of bias. The meta-analysis revealed that the time to exhaustion in running tests was improved with caffeine (g = 0.392; 95% CI = 0.214 to 0.571; p < 0.001, magnitude = medium). Subgroup analysis revealed that caffeine was ergogenic for time to exhaustion trials in both recreational runners (g = 0.469; 95% CI = 0.185 to 0.754; p = 0.001, magnitude = medium) and trained runners (g = 0.344; 95% CI = 0.122 to 0.566; p = 0.002, magnitude = medium). The meta-analysis also showed that the time to complete endurance running time trials was reduced with caffeine in comparison to placebo (g = −0.101; 95% CI = −0.190 to −0.012, p = 0.026, magnitude = small). In summary, caffeine intake showed a meaningful ergogenic effect in increasing the time to exhaustion in running trials and improving performance in running time trials. Hence, caffeine may have utility as an ergogenic aid for endurance running events. More evidence is needed to establish the ergogenic effect of caffeine on endurance running in women or the best dose to maximize the ergogenic benefits of caffeine supplementation.
Topics: Male; Humans; Female; Caffeine; Physical Endurance; Performance-Enhancing Substances; Running; Bicycling; Athletic Performance; Randomized Controlled Trials as Topic
PubMed: 36615805
DOI: 10.3390/nu15010148 -
The Medical Journal of Australia Apr 2023To review and synthesise the global evidence regarding the health effects of electronic cigarettes (e-cigarettes, vapes). (Review)
Review
OBJECTIVE
To review and synthesise the global evidence regarding the health effects of electronic cigarettes (e-cigarettes, vapes).
STUDY DESIGN
Umbrella review (based on major independent reviews, including the 2018 United States National Academies of Sciences, Engineering, and Medicine [NASEM] report) and top-up systematic review of published, peer-reviewed studies in humans examining the relationship of e-cigarette use to health outcomes published since the NASEM report.
DATA SOURCES
Umbrella review: eight major independent reviews published 2017-2021. Systematic review: PubMed, MEDLINE, Scopus, Web of Science, the Cochrane Library, and PsycINFO (articles published July 2017 - July 2020 and not included in NASEM review).
DATA SYNTHESIS
Four hundred eligible publications were included in our synthesis: 112 from the NASEM review, 189 from our top-up review search, and 99 further publications cited by other reviews. There is conclusive evidence linking e-cigarette use with poisoning, immediate inhalation toxicity (including seizures), and e-cigarette or vaping product use-associated lung injury (EVALI; largely but not exclusively for e-liquids containing tetrahydrocannabinol and vitamin E acetate), as well as for malfunctioning devices causing injuries and burns. Environmental effects include waste, fires, and generation of indoor airborne particulate matter (substantial to conclusive evidence). There is substantial evidence that nicotine e-cigarettes can cause dependence or addiction in non-smokers, and strong evidence that young non-smokers who use e-cigarettes are more likely than non-users to initiate smoking and to become regular smokers. There is limited evidence that freebase nicotine e-cigarettes used with clinical support are efficacious aids for smoking cessation. Evidence regarding effects on other clinical outcomes, including cardiovascular disease, cancer, development, and mental and reproductive health, is insufficient or unavailable.
CONCLUSION
E-cigarettes can be harmful to health, particularly for non-smokers and children, adolescents, and young adults. Their effects on many important health outcomes are uncertain. E-cigarettes may be beneficial for smokers who use them to completely and promptly quit smoking, but they are not currently approved smoking cessation aids. Better quality evidence is needed regarding the health impact of e-cigarette use, their safety and efficacy for smoking cessation, and effective regulation.
REGISTRATION
Systematic review: PROSPERO, CRD42020200673 (prospective).
Topics: Young Adult; Adolescent; Child; Humans; Electronic Nicotine Delivery Systems; Nicotine; Prospective Studies; Smoking; Smoking Cessation
PubMed: 36939271
DOI: 10.5694/mja2.51890 -
Psychiatry Research Nov 2023The aim of this review was to determine the effect of psilocybin on depressive symptoms in patients diagnosed with life-threatening illnesses or major depressive... (Meta-Analysis)
Meta-Analysis Review
The aim of this review was to determine the effect of psilocybin on depressive symptoms in patients diagnosed with life-threatening illnesses or major depressive disorder. Systematic searches were conducted to search for randomized clinical trials and open-label trials that evaluated depression symptoms after psilocybin therapy. Data was pooled using a random-effects model. The primary outcome was the standardized mean difference (SMD) in depression severity, determined by calculating the change in depression ratings from baseline to the primary endpoint in the psilocybin arm versus the control arm. The literature search yielded 1734 studies, and 13 studies (n = 686) were included in either qualitative and/or quantitative analyses. The meta-analysis included 9 studies (pooled n = 596) and yielded a large effect size in favour of psilocybin (SMD = -0.78; p<0.001). Risk ratios for response and remission were large and significant in favour of psilocybin. A review of open-label trials showed robust decreases in depressive symptoms following psilocybin administration. These findings provide preliminary evidence for antidepressant efficacy with psilocybin-assisted psychotherapy, however, further studies are needed to evaluate safety and efficacy and to optimize treatment protocols.
Topics: Humans; Psilocybin; Depression; Depressive Disorder, Major; Psychotherapy; Antidepressive Agents; Hallucinogens
PubMed: 37844352
DOI: 10.1016/j.psychres.2023.115531 -
General Hospital Psychiatry 2022Caffeine has been purported to have anxiogenic and panicogenic properties, specifically salient in patients with panic disorder (PD). However, compilations of the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Caffeine has been purported to have anxiogenic and panicogenic properties, specifically salient in patients with panic disorder (PD). However, compilations of the magnitude of the effect of caffeine on anxiety and panic attacks are lacking and potential dose-response relationships have not been examined.
OBJECTIVES
In the present systematic review and meta-analysis, we aimed to examine the acute effects of placebo-controlled caffeine challenge on occurrence of panic attacks and subjective anxiety in patients with PD and healthy controls (HC), including dose-response relationships.
METHODS
Systematic searches were performed in six databases. We included blinded placebo-controlled studies of acute caffeine challenge on panic attacks and/or subjective anxiety in adult patients with PD.
RESULTS
Of the 1893 identified articles, ten met our inclusion criteria. The 9 studies investigating panic attacks included 237 patients, of which 51.1% had a panic attack following caffeine, but none after placebo. Six of these studies compared 128 patients with 115 healthy controls (HC), finding that patients (53.9%) were more vulnerable than HC (1.7%) for panic attacks following caffeine (log RR: 3.47; 95% CI 2.06-4.87). Six studies investigated subjective anxiety in 121 patients and 111 HC following caffeine, with an overall effect indicating increased sensitivity to the anxiogenic effects of caffeine in the patient group (Hedges' g = 1.02 [95% CI: 0.09-1.96]). The restricted range of caffeine employed [400-750 mg] and few studies (3) not using 480 mg prevented any meaningful analysis of a dose-response relationship.
LIMITATIONS
Of the ten studies included, only 2 reported anxiety data for the placebo condition, precluding a proper meta-analysis comparing anxiogenic effects of caffeine and placebo. The restricted dose range used prevented assessment of dose-response relationships.
CONCLUSIONS
The results confirm that caffeine at doses roughly equivalent to 5 cups of coffee induces panic attacks in a large proportion of PD patients and highly discriminates this population from healthy adults. Caffeine also increases anxiety in PD patients as well as among healthy adults at these doses although the exact relationship between caffeine-induced anxiety and panic attacks remains uncertain. The results suggest that caffeine targets important mechanisms related to the pathophysiology of PD.
IMPLICATIONS
Future studies should employ a wider range of caffeine doses and investigate contributions of biological and psychological mechanisms underlying the anxiogenic and panicogenic effects of caffeine. In the clinic, patients with PD should be informed about the panicogenic and anxiogenic effects of caffeine, with the caveat that little is known regarding smaller doses than 480 mg. Registration. PROSPERO (www.crd.york.ac.uk/prospero) registration number CRD42019120220.
Topics: Adult; Anxiety; Anxiety Disorders; Caffeine; Humans; Panic Disorder
PubMed: 34871964
DOI: 10.1016/j.genhosppsych.2021.11.005 -
Current Pain and Headache Reports Aug 2020The purpose of this review is to evaluate and explain our current understanding of the clinical use of low-dose naltrexone in the treatment of chronic pain.
PURPOSE OF REVIEW
The purpose of this review is to evaluate and explain our current understanding of the clinical use of low-dose naltrexone in the treatment of chronic pain.
RECENT FINDINGS
Recent pre-clinical uses and clinical studies further elucidate the use of low-dose naltrexone in the treatment of chronic pain. Low-dose naltrexone (LDN) has shown promise to reduce symptoms related to chronic pain conditions such as fibromyalgia, inflammatory bowel conditions, and multiple sclerosis. The mechanism of LDN appears to be modulation of neuro-inflammation, specifically, the modulation of the glial cells and release of inflammatory chemicals in the central nervous system. These effects appear to unique at low dosage compared to dosage for food and drug administration approved use for alcohol and opioid dependence. We review the evidence that LDN has shown more than promise and should be further investigated in clinical practice.
Topics: Chronic Pain; Fibromyalgia; Humans; Multiple Sclerosis; Naltrexone; Narcotic Antagonists; Opioid-Related Disorders
PubMed: 32845365
DOI: 10.1007/s11916-020-00898-0 -
The Cochrane Database of Systematic... Feb 2023Myopia is a common refractive error, where elongation of the eyeball causes distant objects to appear blurred. The increasing prevalence of myopia is a growing global... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Myopia is a common refractive error, where elongation of the eyeball causes distant objects to appear blurred. The increasing prevalence of myopia is a growing global public health problem, in terms of rates of uncorrected refractive error and significantly, an increased risk of visual impairment due to myopia-related ocular morbidity. Since myopia is usually detected in children before 10 years of age and can progress rapidly, interventions to slow its progression need to be delivered in childhood.
OBJECTIVES
To assess the comparative efficacy of optical, pharmacological and environmental interventions for slowing myopia progression in children using network meta-analysis (NMA). To generate a relative ranking of myopia control interventions according to their efficacy. To produce a brief economic commentary, summarising the economic evaluations assessing myopia control interventions in children. To maintain the currency of the evidence using a living systematic review approach. SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register), MEDLINE; Embase; and three trials registers. The search date was 26 February 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of optical, pharmacological and environmental interventions for slowing myopia progression in children aged 18 years or younger. Critical outcomes were progression of myopia (defined as the difference in the change in spherical equivalent refraction (SER, dioptres (D)) and axial length (mm) in the intervention and control groups at one year or longer) and difference in the change in SER and axial length following cessation of treatment ('rebound'). DATA COLLECTION AND ANALYSIS: We followed standard Cochrane methods. We assessed bias using RoB 2 for parallel RCTs. We rated the certainty of evidence using the GRADE approach for the outcomes: change in SER and axial length at one and two years. Most comparisons were with inactive controls.
MAIN RESULTS
We included 64 studies that randomised 11,617 children, aged 4 to 18 years. Studies were mostly conducted in China or other Asian countries (39 studies, 60.9%) and North America (13 studies, 20.3%). Fifty-seven studies (89%) compared myopia control interventions (multifocal spectacles, peripheral plus spectacles (PPSL), undercorrected single vision spectacles (SVLs), multifocal soft contact lenses (MFSCL), orthokeratology, rigid gas-permeable contact lenses (RGP); or pharmacological interventions (including high- (HDA), moderate- (MDA) and low-dose (LDA) atropine, pirenzipine or 7-methylxanthine) against an inactive control. Study duration was 12 to 36 months. The overall certainty of the evidence ranged from very low to moderate. Since the networks in the NMA were poorly connected, most estimates versus control were as, or more, imprecise than the corresponding direct estimates. Consequently, we mostly report estimates based on direct (pairwise) comparisons below. At one year, in 38 studies (6525 participants analysed), the median change in SER for controls was -0.65 D. The following interventions may reduce SER progression compared to controls: HDA (mean difference (MD) 0.90 D, 95% confidence interval (CI) 0.62 to 1.18), MDA (MD 0.65 D, 95% CI 0.27 to 1.03), LDA (MD 0.38 D, 95% CI 0.10 to 0.66), pirenzipine (MD 0.32 D, 95% CI 0.15 to 0.49), MFSCL (MD 0.26 D, 95% CI 0.17 to 0.35), PPSLs (MD 0.51 D, 95% CI 0.19 to 0.82), and multifocal spectacles (MD 0.14 D, 95% CI 0.08 to 0.21). By contrast, there was little or no evidence that RGP (MD 0.02 D, 95% CI -0.05 to 0.10), 7-methylxanthine (MD 0.07 D, 95% CI -0.09 to 0.24) or undercorrected SVLs (MD -0.15 D, 95% CI -0.29 to 0.00) reduce progression. At two years, in 26 studies (4949 participants), the median change in SER for controls was -1.02 D. The following interventions may reduce SER progression compared to controls: HDA (MD 1.26 D, 95% CI 1.17 to 1.36), MDA (MD 0.45 D, 95% CI 0.08 to 0.83), LDA (MD 0.24 D, 95% CI 0.17 to 0.31), pirenzipine (MD 0.41 D, 95% CI 0.13 to 0.69), MFSCL (MD 0.30 D, 95% CI 0.19 to 0.41), and multifocal spectacles (MD 0.19 D, 95% CI 0.08 to 0.30). PPSLs (MD 0.34 D, 95% CI -0.08 to 0.76) may also reduce progression, but the results were inconsistent. For RGP, one study found a benefit and another found no difference with control. We found no difference in SER change for undercorrected SVLs (MD 0.02 D, 95% CI -0.05 to 0.09). At one year, in 36 studies (6263 participants), the median change in axial length for controls was 0.31 mm. The following interventions may reduce axial elongation compared to controls: HDA (MD -0.33 mm, 95% CI -0.35 to 0.30), MDA (MD -0.28 mm, 95% CI -0.38 to -0.17), LDA (MD -0.13 mm, 95% CI -0.21 to -0.05), orthokeratology (MD -0.19 mm, 95% CI -0.23 to -0.15), MFSCL (MD -0.11 mm, 95% CI -0.13 to -0.09), pirenzipine (MD -0.10 mm, 95% CI -0.18 to -0.02), PPSLs (MD -0.13 mm, 95% CI -0.24 to -0.03), and multifocal spectacles (MD -0.06 mm, 95% CI -0.09 to -0.04). We found little or no evidence that RGP (MD 0.02 mm, 95% CI -0.05 to 0.10), 7-methylxanthine (MD 0.03 mm, 95% CI -0.10 to 0.03) or undercorrected SVLs (MD 0.05 mm, 95% CI -0.01 to 0.11) reduce axial length. At two years, in 21 studies (4169 participants), the median change in axial length for controls was 0.56 mm. The following interventions may reduce axial elongation compared to controls: HDA (MD -0.47mm, 95% CI -0.61 to -0.34), MDA (MD -0.33 mm, 95% CI -0.46 to -0.20), orthokeratology (MD -0.28 mm, (95% CI -0.38 to -0.19), LDA (MD -0.16 mm, 95% CI -0.20 to -0.12), MFSCL (MD -0.15 mm, 95% CI -0.19 to -0.12), and multifocal spectacles (MD -0.07 mm, 95% CI -0.12 to -0.03). PPSL may reduce progression (MD -0.20 mm, 95% CI -0.45 to 0.05) but results were inconsistent. We found little or no evidence that undercorrected SVLs (MD -0.01 mm, 95% CI -0.06 to 0.03) or RGP (MD 0.03 mm, 95% CI -0.05 to 0.12) reduce axial length. There was inconclusive evidence on whether treatment cessation increases myopia progression. Adverse events and treatment adherence were not consistently reported, and only one study reported quality of life. No studies reported environmental interventions reporting progression in children with myopia, and no economic evaluations assessed interventions for myopia control in children.
AUTHORS' CONCLUSIONS
Studies mostly compared pharmacological and optical treatments to slow the progression of myopia with an inactive comparator. Effects at one year provided evidence that these interventions may slow refractive change and reduce axial elongation, although results were often heterogeneous. A smaller body of evidence is available at two or three years, and uncertainty remains about the sustained effect of these interventions. Longer-term and better-quality studies comparing myopia control interventions used alone or in combination are needed, and improved methods for monitoring and reporting adverse effects.
Topics: Humans; Child; Network Meta-Analysis; Myopia; Refractive Errors; Atropine; Refraction, Ocular
PubMed: 36809645
DOI: 10.1002/14651858.CD014758.pub2 -
The International Journal of... Mar 2023Psychedelics are a unique class of drug that commonly produce vivid hallucinations as well as profound psychological and mystical experiences. A grouping of...
Psychedelics are a unique class of drug that commonly produce vivid hallucinations as well as profound psychological and mystical experiences. A grouping of interconnected brain regions characterized by increased temporal coherence at rest have been termed the Default Mode Network (DMN). The DMN has been the focus of numerous studies assessing its role in self-referencing, mind wandering, and autobiographical memories. Altered connectivity in the DMN has been associated with a range of neuropsychiatric conditions such as depression, anxiety, post-traumatic stress disorder, attention deficit hyperactive disorder, schizophrenia, and obsessive-compulsive disorder. To date, several studies have investigated how psychedelics modulate this network, but no comprehensive review, to our knowledge, has critically evaluated how major classical psychedelic agents-lysergic acid diethylamide, psilocybin, and ayahuasca-modulate the DMN. Here we present a systematic review of the knowledge base. Across psychedelics there is consistent acute disruption in resting state connectivity within the DMN and increased functional connectivity between canonical resting-state networks. Various models have been proposed to explain the cognitive mechanisms of psychedelics, and in one model DMN modulation is a central axiom. Although the DMN is consistently implicated in psychedelic studies, it is unclear how central the DMN is to the therapeutic potential of classical psychedelic agents. This article aims to provide the field with a comprehensive overview that can propel future research in such a way as to elucidate the neurocognitive mechanisms of psychedelics.
Topics: Hallucinogens; Default Mode Network; Psilocybin; Lysergic Acid Diethylamide; Brain; Magnetic Resonance Imaging
PubMed: 36272145
DOI: 10.1093/ijnp/pyac074