scholarly journals A systematic review of neuroimaging and acute cannabis exposure in age-of-risk for psychosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lani Cupo ◽  
Eric Plitman ◽  
Elisa Guma ◽  
M. Mallar Chakravarty

AbstractAcute exposure to cannabis has been associated with an array of cognitive alterations, increased risk for neuropsychiatric illness, and other neuropsychiatric sequelae including the emergence of acute psychotic symptoms. However, the brain alterations associating cannabis use and these behavioral and clinical phenotypes remains disputed. To this end, neuroimaging can be a powerful technique to non-invasively study the impact of cannabis exposure on brain structure and function in both humans and animal models. While chronic exposure studies provide insight into how use may be related to long-term outcomes, acute exposure may reveal interesting information regarding the immediate impact of use and abuse on brain circuits. Understanding these alterations could reveal the connection with symptom dimensions in neuropsychiatric disorders and, more specifically with psychosis. The purpose of the present review is to: 1) provide an update on the findings of pharmacological neuroimaging studies examining the effects of administered cannabinoids and 2) focus the discussion on studies that examine the sensitive window for the emergence of psychosis. Current literature indicates that cannabis exposure has varied effects on the brain, with the principal compounds in cannabis (delta-9-tetrahydrocannabinol and cannabidiol) altering activity across different brain regions. Importantly, we also discovered critical gaps in the literature, particularly regarding sex-dependent responses and long-term effects of chronic exposure. Certain networks often characterized as dysregulated in psychosis, like the default mode network and limbic system, were also impacted by THC exposure, identifying areas of particular interest for future work investigating the potential relationship between the two.

Meditation refers to a state of mind of relaxation and concentration, where generally the mind and body is at rest. The process of meditation reflects the state of the brain which is distinct from sleep or typical wakeful states of consciousness. Meditative practices usually involve regulation of emotions and monitoring of attention. Over the past decade there has been a tremendous increase in an interest to study the neural mechanisms involved in meditative practices. It could also be beneficial to explore if the effect of meditation is altered by the number of years of meditation practice. Functional Magnetic Resonance Imaging (fMRI) is a very useful imaging technique which can be used to perform this analysis due to its inherent benefits, mainly it being a non-invasive technique. Functional activation and connectivity analysis can be performed on the fMRI data to find the active regions and the connectivity in the brain regions. Functional connectivity is defined as a simple temporal correlation between anatomically separate, active neural regions. Functional connectivity gives the statistical dependencies between regional time series. It is a statistical concept and is quantified using metrics like Correlation. In this study, a comparison is made between functional connectivity in the brain regions of long term meditation practitioners (LTP) and short-term meditation practitioners (STP) to see the differences and similarities in the connectivity patterns. From the analysis, it is evident that in fact there is a difference in connectivity between long term and short term practitioners and hence continuous practice of meditation can have long term effects.


2019 ◽  
Vol 46 (3) ◽  
pp. 484-495 ◽  
Author(s):  
Federico E Turkheimer ◽  
Pierluigi Selvaggi ◽  
Mitul A Mehta ◽  
Mattia Veronese ◽  
Fernando Zelaya ◽  
...  

Abstract The use of antipsychotic medication to manage psychosis, principally in those with a diagnosis of schizophrenia or bipolar disorder, is well established. Antipsychotics are effective in normalizing positive symptoms of psychosis in the short term (delusions, hallucinations and disordered thought). Their long-term use is, however, associated with side effects, including several types of movement (extrapyramidal syndrome, dyskinesia, akathisia), metabolic and cardiac disorders. Furthermore, higher lifetime antipsychotic dose-years may be associated with poorer cognitive performance and blunted affect, although the mechanisms driving the latter associations are not well understood. In this article, we propose a novel model of the long-term effects of antipsychotic administration focusing on the changes in brain metabolic homeostasis induced by the medication. We propose here that the brain metabolic normalization, that occurs in parallel to the normalization of psychotic symptoms following antipsychotic treatment, may not ultimately be sustainable by the cerebral tissue of some patients; these patients may be characterized by already reduced oxidative metabolic capacity and this may push the brain into an unsustainable metabolic envelope resulting in tissue remodeling. To support this perspective, we will review the existing data on the brain metabolic trajectories of patients with a diagnosis of schizophrenia as indexed using available neuroimaging tools before and after use of medication. We will also consider data from pre-clinical studies to provide mechanistic support for our model.


2018 ◽  
Vol 1 (1) ◽  
pp. 36-46
Author(s):  
Patrick S Ledwidge

Sports-related Concussions (SRC) and their potential long-term effects are a growing concern among athletes and their families. Research utilizing functional brain imaging/recording techniques (e.g., fMRI, ERP) seeks to explain how neurocognitive brain activity changes in the days and years following SRC. Although language deficits are documented following non-sports related concussion there remains a striking lack of research on how SRCs may influence the language system and their supporting neural mechanisms. Neuroimaging findings, however, demonstrate that SRCs alter structural and functional pathways within the frontotemporal language network. Brain regions included in this network generate language-related event-related brain potentials (ERPs), including the N400 and P600. ERPs have been used to demonstrate long-term neurocognitive alterations associated with concussion and may also provide objective and robust markers of SRC-induced changes to the language system.


2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi161-vi161
Author(s):  
Dorela Shuboni-Mulligan ◽  
Demarrius Young Jr. ◽  
Julianie De La Cruz Minyety ◽  
Nicole Briceno ◽  
Amanda King ◽  
...  

Abstract BACKGROUND Disrupted sleep, including daytime hypersomnolence, is a core symptom reported by primary brain tumor patients and often manifests after radiotherapy. The biological mechanisms driving cranial radiation-induced hypersomnolence (C-RIH) remain unclear but we hypothesize this may result from damage to neural circuits controlling sleep behavior. We developed a mouse model of C-RIH to explore the impact of radiation on the brain: examining region-specific differences in acute DNA damage response and neuroanatomic structure. METHODS Mice received whole brain radiation then behaviors were monitored using PhenoTyper® cages to determine optimal dose and long-term effects. To test short-term neurologic effects, brains were collected 1hr post-radiation then stained for γH2AX, a signal for DNA damage. Long-term effects were quantified 1-month post-treatment using neuroimaging to determine brain volume and T1 mapping changes in regions associated with sleep, circadian rhythms, and cognition. RESULTS Mice displayed decreased general activity and increased daytime sleep in a dose-dependent and sustained manner. Histologic staining demonstrated that DNA damage following radiation varies across the brain, with homeostatic sleep regions and cognitive regions expressing higher levels of γH2AX than the circadian suprachiasmatic nucleus. These findings were supported by in vitro studies comparing radiation effects in SCN and cortical astrocytes using both trypan blue (F(1,18)=235.937, p< 0.001) and clonogenic assays (F(1,24)=40.796, < 0.001). Brain volumes were significantly smaller in irradiated than sham animals in the hippocampus (t(4)=3.833, p=0.019) and the pontine central grey (t(4)=3.504, p=0.025). T1 maps also showed significant changes in relaxation times in many cognitive regions but not sleep or circadian areas. CONCLUSIONS These findings suggest that the homeostatic sleep region and cognitive circuits are vulnerable to radiation and may be relevant to the development of treatment plans in patients. We plan to introduce intracranial tumor to the model to evaluate the impact of timing of treatment and C-RIH on survival.


2020 ◽  
Vol 23 (11) ◽  
pp. 751-761
Author(s):  
Danilo De Gregorio ◽  
Joshua Dean Conway ◽  
Martha-Lopez Canul ◽  
Luca Posa ◽  
Francis Rodriguez Bambico ◽  
...  

Abstract Background Chronic exposure to D9-tetrahydrocannabinol (THC), the main pharmacological component of cannabis, during adolescence has been shown to be associated with an increased risk of depression and suicidality in humans. Little is known about the impact of the long-term effects of chronic exposure to low doses of THC in adolescent compared with adult rodents. Methods THC (1 mg/kg i.p., once per day) or vehicle was administered for 20 days in both adolescent (post-natal day 30–50) and young adult rats (post-natal day 50–70). After a long washout period (20 days), behavioral tests and electrophysiological recordings of serotonin and norepinephrine neurons were carried out. Results Adolescent THC exposure resulted in depressive behaviors: decreased latency to first immobility in the forced swim test and increased anhedonia in the sucrose preference test. Decreased entries in the open arms were observed in the elevated plus maze after adolescent and adult exposure, indicating an anxious phenotype. A significant reduction in dorsal raphe serotonergic neural activity without a change in locus coeruleus noradrenergic neural activity was found after adolescent and adult exposure. Conclusions Altogether, these findings suggest that chronic low-dose THC exposure during the critical developmental period of adolescence and during adulthood could result in increased vulnerability of the serotonin system accompanied by anxiety symptoms. However, depressive phenotypes occur only after adolescent exposure but not after adult exposure, underscoring the greater vulnerability of young ages to the mental effects of cannabis.


Psibernetika ◽  
2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Devina Calista ◽  
Garvin Garvin

<p><em>Child abuse by parents is common in households. The impact of violence on children will bring short-term effects and long-term effects that can be attributed to their various emotional, behavioral and social problems in the future; especially in late adolescence that will enter adulthood. Resilience factors increase the likelihood that adolescents who are victims of childhood violence recover from their past experiences</em><em>,</em><em> become more powerful individuals and have a better life. The purpose of this study was to determine the source of resilience in late adolescents who experienced violence from parents in their childhood. This research uses qualitative research methods with in-depth interviews as a method of data collection. The result shows that the three research participants have the aspects of "I Have", "I Am", and "I Can"; a participant has "I Can" aspects as a source of resilience, and one other subject has no source of resilience. The study concluded that parental affection and acceptance of the past experience have role to the three sources of resilience (I Have, I Am, and I Can)</em></p><p><em> </em></p><p><strong><em>Keyword : </em></strong><em>Resilience, adolescence, violence, parents</em></p>


Author(s):  
Balázs Égert ◽  
Peter Gal

This chapter describes and discusses a new supply-side framework that quantifies the impact of structural reforms on per capita income in OECD countries. It presents the overall macroeconomic impacts of reforms by aggregating over the effects on physical capital, employment, and productivity through a production function. On the basis of reforms defined as observed changes in policies, the chapter finds that product market regulation has the largest overall single policy impact five years after the reforms. But the combined impact of all labour market policies is considerably larger than that of product market regulation. The paper also shows that policy impacts can differ at different horizons. The overall long-term effects on GDP per capita of policies transiting through capital deepening can be considerably larger than the five- to ten-year impacts. By contrast, the long-term impact of policies coming only via the employment rate channel materializes at a shorter horizon.


2021 ◽  
pp. 1-8
Author(s):  
Joseph M. Boden ◽  
James A. Foulds ◽  
Giles Newton-Howes ◽  
Rebecca McKetin

Abstract Background This study examined the association between methamphetamine use and psychotic symptoms in a New Zealand general population birth cohort (n = 1265 at birth). Methods At age 18, 21, 25, 30, and 35, participants reported on their methamphetamine use and psychotic symptoms in the period since the previous interview. Generalized estimating equations modelled the association between methamphetamine use and psychotic symptoms (percentage reporting any symptom, and number of symptoms per participant). Confounding factors included childhood individual characteristics, family socioeconomic circumstances and family functioning. Long term effects of methamphetamine use on psychotic symptoms were assessed by comparing the incidence of psychotic symptoms at age 30–35 for those with and without a history of methamphetamine use prior to age 30. Results After adjusting for confounding factors and time-varying covariate factors including concurrent cannabis use, methamphetamine use was associated with a modest increase in psychosis risk over five waves of data (adjusted odds ratio (OR) 1.33, 95% confidence interval (CI) 1.03–1.72 for the percentage measure; and IRR 1.24, 95% CI 1.02–1.50 for the symptom count measure). The increased risk of psychotic symptoms was concentrated among participants who had used at least weekly at any point (adjusted OR 2.85, 95% CI 1.21–6.69). Use of methamphetamine less than weekly was not associated with increased psychosis risk. We found no evidence for a persistent vulnerability to psychosis in the absence of continuing methamphetamine use. Conclusion Methamphetamine use is associated with increased risk of psychotic symptoms in the general population. Increased risk is chiefly confined to people who ever used regularly (at least weekly), and recently.


Author(s):  
Rutao Wang ◽  
Scot Garg ◽  
Chao Gao ◽  
Hideyuki Kawashima ◽  
Masafumi Ono ◽  
...  

Abstract Aims To investigate the impact of established cardiovascular disease (CVD) on 10-year all-cause death following coronary revascularization in patients with complex coronary artery disease (CAD). Methods The SYNTAXES study assessed vital status out to 10 years of patients with complex CAD enrolled in the SYNTAX trial. The relative efficacy of PCI versus CABG in terms of 10-year all-cause death was assessed according to co-existing CVD. Results Established CVD status was recorded in 1771 (98.3%) patients, of whom 827 (46.7%) had established CVD. Compared to those without CVD, patients with CVD had a significantly higher risk of 10-year all-cause death (31.4% vs. 21.7%; adjusted HR: 1.40; 95% CI 1.08–1.80, p = 0.010). In patients with CVD, PCI had a non-significant numerically higher risk of 10-year all-cause death compared with CABG (35.9% vs. 27.2%; adjusted HR: 1.14; 95% CI 0.83–1.58, p = 0.412). The relative treatment effects of PCI versus CABG on 10-year all-cause death in patients with complex CAD were similar irrespective of the presence of CVD (p-interaction = 0.986). Only those patients with CVD in ≥ 2 territories had a higher risk of 10-year all-cause death (adjusted HR: 2.99, 95% CI 2.11–4.23, p < 0.001) compared to those without CVD. Conclusions The presence of CVD involving more than one territory was associated with a significantly increased risk of 10-year all-cause death, which was non-significantly higher in complex CAD patients treated with PCI compared with CABG. Acceptable long-term outcomes were observed, suggesting that patients with established CVD should not be precluded from undergoing invasive angiography or revascularization. Trial registration SYNTAX: ClinicalTrials.gov reference: NCT00114972. SYNTAX Extended Survival: ClinicalTrials.gov reference: NCT03417050. Graphic abstract


2020 ◽  
Vol 41 (S1) ◽  
pp. s258-s259
Author(s):  
James Harrigan ◽  
Ebbing Lautenbach ◽  
Emily Reesey ◽  
Magda Wernovsky ◽  
Pam Tolomeo ◽  
...  

Background: Clinically diagnosed ventilator-associated pneumonia (VAP) is common in the long-term acute-care hospital (LTACH) setting and may contribute to adverse ventilator-associated events (VAEs). Pseudomonas aeruginosa is a common causative organism of VAP. We evaluated the impact of respiratory P. aeruginosa colonization and bacterial community dominance, both diagnosed and undiagnosed, on subsequent P. aeruginosa VAP and VAE events during long-term acute care. Methods: We enrolled 83 patients on LTACH admission for ventilator weaning, performed longitudinal sampling of endotracheal aspirates followed by 16S rRNA gene sequencing (Illumina HiSeq), and bacterial community profiling (QIIME2). Statistical analysis was performed with R and Stan; mixed-effects models were fit to relate the abundance of respiratory Psa on admission to clinically diagnosed VAP and VAE events. Results: Of the 83 patients included, 12 were diagnosed with P. aeruginosa pneumonia during the 14 days prior to LTACH admission (known P. aeruginosa), and 22 additional patients received anti–P. aeruginosa antibiotics within 48 hours of admission (suspected P. aeruginosa); 49 patients had no known or suspected P. aeruginosa (unknown P. aeruginosa). Among the known P. aeruginosa group, all 12 patients had P. aeruginosa detectable by 16S sequencing, with elevated admission P. aeruginosa proportional abundance (median, 0.97; IQR, 0.33–1). Among the suspected P. aeruginosa group, all 22 patients had P. aeruginosa detectable by 16S sequencing, with a wide range of admission P. aeruginosa proportional abundance (median, 0.0088; IQR, 0.00012–0.31). Of the 49 patients in the unknown group, 47 also had detectable respiratory Psa, and many had high P. aeruginosa proportional abundance at admission (median, 0.014; IQR, 0.00025–0.52). Incident P. aeruginosa VAP was observed within 30 days in 4 of the known P. aeruginosa patients (33.3%), 5 of the suspected P. aeruginosa patients (22.7%), and 8 of the unknown P. aeruginosa patients (16.3%). VAE was observed within 30 days in 1 of the known P. aeruginosa patients (8.3%), 2 of the suspected P. aeruginosa patients (9.1%), and 1 of the unknown P. aeruginosa patients (2%). Admission P. aeruginosa abundance was positively associated with VAP and VAE risk in all groups, but the association only achieved statistical significance in the unknown group (type S error <0.002 for 30-day VAP and <0.011 for 30-day VAE). Conclusions: We identified a high prevalence of unrecognized respiratory P. aeruginosa colonization among patients admitted to LTACH for weaning from mechanical ventilation. The admission P. aeruginosa proportional abundance was strongly associated with increased risk of incident P. aeruginosa VAP among these patients.Funding: NoneDisclosures: None


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