Whilst obesity is associated with a higher risk of cognitive impairment, the influence of weight loss on cognitive function in obese/overweight people is equivocal. We conducted a meta-analysis of randomized controlled trials (RCTs) and longitudinal studies evaluating the influence of voluntary weight loss on cognitive function in obese/overweight individuals. Articles were acquired from a systematic search of major databases from inception till 01/2016. A xandom effect meta-analysis of weight loss interventions (diet, physical activity, bariatric surgery) on different cognitive domains (memory, attention, executive functions, language and motor speed) was conducted. Twenty studies (13 longitudinal studies = 551 participants; 7 RCTs = 328 treated vs. 140 controls) were included. Weight loss was associated with a significant improvement in attention and memory in both longitudinal studies and RCTs, whereas executive function and language improved in longitudinal and RCT studies, respectively. In conclusion, intentional weight loss in obese/overweight people is associated with improvements in performance across various cognitive domains. Future adequately powered RCTs are required to confirm/refute these findings. (C) 2016 Elsevier Ltd. All rights reserved.

Genetic-neuroimaging paradigms could provide insights regarding the pathophysiology of bipolar disorder (BD). Nevertheless, findings have been inconsistent across studies. A systematic review of gene-imaging studies involving individuals with BD was conducted across electronic major databases from inception until January 9th, 2017. Forty-four studies met eligibility criteria (N= 2122 BD participants). Twenty-six gene variants were investigated across candidate gene studies and 4 studies used a genome-wide association approach. Replicated evidence (i.e. in> 2 studies) suggests that individuals with BD carrying the BDNF Val66Met risk allele could have reduced hippocampal volumes compared to non-carriers. This review underscores the potential of gene-neuroimaging paradigms to provide mechanistic insights for BD. However, this systematic review found a single replicated finding. Suggestions to improve the reproducibility of this emerging field are provided, including the adoption of a trans-diagnostic approach.

Individuals living with schizophrenia are 2-3 times more likely to experience type 2 diabetes mellitus. Diabetes medication adherence is essential to reduce morbidity and mortality in this population. We conducted a meta analysis of diabetes medication adherence among people with schizophrenia, and compared this to those without schizophrenia. A systematic search strategy was used to identify all articles reporting adherence to diabetes medications among patients with schizophrenia. In total, 10 unique studies reporting data from 33,910 people with schizophrenia were included. Random effects meta-analysis showed people with schizophrenia adhered to medication on 77.3% of days prescribed (n=32080, 95%CI=73.6-81%, I-2=99.2%,), and adhered on 4.6% more days per year than those without schizophrenia (p < 0.01, 95%CI=2.4-6.7%, I-2=92.5%, schizophrenia n=19367, controls=170,853). Furthermore, 56% of individuals with schizophrenia (n=33680) were considered adherent (i.e. > 80% adherence over 12-24 month) to diabetes medication, which was significantly more than those without schizophrenia (OR=1.34, 95%C1: 1.18-1.52, p < 0.01). Factors which were positively associated with diabetes medication adherence were age, number of outpatient visits, along with multiple medication administration variables. Future prospective research should examine diabetes monitoring, medication prescription, and subsequent adherence in fully representative samples. Novel interventions for maximizing compliance to diabetes medication in this vulnerable population should also be explored.

Despite the long-standing belief in the analgesic properties of alcohol, experimental studies have produced mixed results. This meta-analysis aimed to clarify whether alcohol produces a decrease in experimentally-induced pain and to determine the magnitude of any such effect. PubMed, PsycINFO, and Embase databases were searched from inception until April 21, 2016 for controlled studies examining the effect of quantified dosages of alcohol on pain response to noxious stimulation. Eighteen studies involving 404 participants were identified providing alcohol versus no alcohol comparisons for 13 tests of pain threshold (n = 212) and 9 tests of pain intensity ratings (n = 192). Random effects meta-analysis of standardized mean difference (SMD) provided robust support for analgesic effects of alcohol. A mean blood alcohol content (BAC) of approximately .08% (3-4 standard drinks) produced a small elevation of pain threshold (SMD [95% CI] = .35 [.17-.54], P = .002), and a moderate to large reduction in pain intensity ratings (SMD [95% CI] = .64 [.37-.91], P < .0001), or equivalently, a mean reduction of 1.25 points on a 0- to 10-point pain rating scale. Furthermore, increasing BAC resulted in increasing analgesia, with each .02% BAC increment producing an increase of SMD = .11 for pain threshold and SMD = .20 for reduced pain intensity. Some evidence of publication bias emerged, but statistical correction methods suggested minimal impact on effect size. Taken together, findings suggest that alcohol is an effective analgesic that delivers clinically-relevant reductions in ratings of pain intensity, which could explain alcohol misuse in those with persistent pain despite its potential consequences for long-term health. Further research is needed to corroborate these findings for clinical pain states. Perspective: This meta-analysis provides robust evidence for the analgesic properties of alcohol, which could potentially contribute to alcohol misuse in pain patients. Strongest analgesia occurs for alcohol levels exceeding World Health Organization guidelines for low-risk drinking and suggests raising awareness of alternative, less harmful pain interventions to vulnerable patients may be beneficial. (C) 2016 by the American Pain Society

People with psychosis have high prevalence of low vitamin D levels but the correlates and relevance of this deficiency are unclear. A systematic search of major databases from inception to 03/2016 was undertaken investigating correlates of vitamin D in people with psychosis. Data was summarised with a best evidence synthesis. Across 23 included studies (n=1770 psychosis, n=8171 controls) a mean difference in vitamin D levels between both groups of 11.14 ng/ml 0.59 was found. 53 unique correlations between vitamin D and outcomes in people with psychosis were identified. The evidence base was broadly equivocal although season of blood sampling (67% of studies found a positive correlation with warmer seasons) and parathyroid hormone (100% of studies found a negative correlation) were associated with vitamin D levels. The most commonly non correlated variables were: BMI (83% found no correlation), age (73%), gender (86%), smoking (100%), duration of illness (100%) and general assessment of functioning score (100%). In conclusion, whilst many unique correlates have been investigated, there is weak and inconclusive evidence regarding the consistency and meaning of the correlates of vitamin D levels in people with psychosis. Future longitudinal studies should consider the correlates of vitamin D in people with psychosis.

Physically-active video games ('exergames') have recently gained popularity for leisure and entertainment purposes. Using exergames to combine physical activity and cognitively-demanding tasks may offer a novel strategy to improve cognitive functioning. Therefore, this systematic review and meta-analysis was performed to establish effects of exergames on overall cognition and specific cognitive domains in clinical and non-clinical populations. We identified 17 eligible RCTs with cognitive outcome data for 926 participants. Random-effects meta-analyses found exergames significantly improved global cognition (g = 0.436, 95% CI = 0.18-0.69, p = 0.001). Significant effects still existed when excluding waitlist-only controlled studies, and when comparing to physical activity interventions. Furthermore, benefits of exergames where observed for both healthy older adults and clinical populations with conditions associated with neurocognitive impairments (all p < 0.05). Domain-specific analyses found exergames improved executive functions, attentional processing and visuospatial skills. The findings present the first meta-analytic evidence for effects of exergames on cognition. Future research must establish which patient/treatment factors influence efficacy of exergames, and explore neurobiological mechanisms of action.