Alcohol and cognitive impairment

Resurgence of ethanol seeking following voluntary abstinence produced by nondrug differential reinforcement of other behavior

Resurgence refers to the relapse of a target behavior following the worsening of a source of alternative reinforcement that was made available during response elimination. Most laboratory analyses of resurgence have used a combination of extinction and alternative reinforcement to reduce target behavior. In contingency-management treatments for alcohol use disorder, however, alcohol use is not placed on extinction. Instead, participants voluntarily abstain from alcohol use to access nondrug alternative reinforcers. Inasmuch, additional laboratory research on resurgence following voluntary abstinence is warranted. The present experiment evaluated resurgence of rats' ethanol seeking following voluntary abstinence produced by differential reinforcement of other behavior (DRO). Lever pressing produced ethanol reinforcers during baseline phases. During DRO phases, lever pressing continued to produce ethanol and food reinforcers were delivered according to resetting DRO schedules. Ethanol and food reinforcers were suspended during resurgence test phases to evaluate resurgence following voluntary abstinence. Lever pressing was elevated during baseline phases and occurred at near-zero rates during DRO phases. During the resurgence test phases, lever pressing increased, despite that it no longer produced ethanol. The procedure introduced here may help researchers better understand the variables that affect voluntary abstinence from ethanol seeking and resurgence following voluntary abstinence.

Successful word retraining, maintenance and transference of practice to everyday activities: A single case experimental design in early onset alcohol-induced brain damage

Word retraining programs have been shown to improve naming ability post-stroke and in progressive aphasias. Here, we investigated benefits for a 22-year-old Danish man (DJ), whose difficulties followed brain damage from heavy alcohol misuse. Using a multiple baseline-across-behaviours design (target behaviour: retrieval of word list items), DJ completed a 4-week "Look, Listen, Repeat" program on a computer. Ninety personally relevant target words were selected to create three matched lists. List 1 was trained for 10 sessions over 2 weeks, followed by 9 sessions for List 2 over 2 weeks, while the third list remained untrained. Naming performance was evaluated at baseline, during the intervention, and at 1 and 4 months post-training. Naming improved following each intervention block (p < .001), with only one data point overlapping between the baseline and treatment phases for trained items. Untrained words remained unchanged (p = 1.00), with 50% of data points non-overlapping across baseline to treatment phases. Performance was maintained over time, and appeared to generalize, with DJ naming more trained objects in their natural setting (85%) than untrained items (64%). While more evidence is needed, brief (20-minute), intensive (5-day/week) word retraining programs may assist word retrieval for people with brain damage associated with alcohol misuse.

Nondrug reinforcers contingent on alternative behavior or abstinence increase resistance to extinction and reinstatement of ethanol-maintained behavior

The effects of delivering nondrug alternative reinforcement on resistance to extinction and reinstatement of rats' ethanol-maintained lever pressing were evaluated in two experiments. In both, rats self-administered ethanol by lever pressing in a two-component multiple schedule during baseline. In the Rich component, alternative food reinforcement was made available for performing an alternative response (Experiment 1) or according to a differential-reinforcement-of-other-behavior schedule for lever pressing (Experiment 2). In the Lean component, only ethanol was available. Moreover, the frequency of alternative reinforcement was manipulated across conditions in Experiment 1. Following baseline, lever pressing was extinguished in both components by suspending ethanol reinforcement, and alternative food reinforcers were discontinued. Finally, to test for reinstatement, ethanol reinforcers were delivered independently of lever pressing in both components. In both experiments, proportion-of-baseline response rates were higher during extinction and reinstatement testing in the Rich component than in the Lean component (although differentiation was not observed at the lowest frequency of alternative reinforcement in Experiment 1). Thus, alternative nondrug reinforcers increased resistance to extinction and reinstatement of rats' ethanol-maintained lever pressing, even when those reinforcers were delivered contingently on an alternative response or on abstinence from lever pressing.

Categorising a problem: alcohol and dementia

Alcoholism is a chronic relapsing disorder that can include extended periods of abstinence followed by relapse to heavy drinking. Decades of evidence have clearly shown that long-term, chronic ethanol exposure produces brain damage in humans. The article aims to review the relationship between alcohol use and dementia. Medline and Google Scholar searches were conducted for relevant articles, chapters and books published until 2019. Search terms used included alcohol consumption, alcohol-related dementia, alcohol use disorders, chronic alcoholism, dementia. Publications found through this indexed search were reviewed for further relevant references. Alcohol acts on the central nervous system via both direct and indirect effects, frequently a combination of the two. There is consensus that alcohol contributes to the acquisition of cognitive deficits in late life. However, there are doubts regarding the aetiopathogenesis, nosological status and prevalence of alcohol-related dementia and still, there is much debate over how much alcohol consumption will lead to alcohol-related dementia.

The possible role of CREB-BDNF signaling pathway in neuroprotective effects of minocycline against alcohol-induced neurodegeneration: molecular and behavioral evidences

Abuse of alcohol triggers neurodegeneration in human brain. Minocycline has characteristics conferring neuroprotection. Current study evaluates the role of the CREB-BDNF signaling pathway in mediating minocycline's neuroprotective effects against alcohol-induced neurodegeneration. Seventy adult male rats were randomly split into groups 1 and 2 that received saline and alcohol (2 g/kg/day by gavage, once daily), respectively, and groups 3, 4, 5, and 6 were treated simultaneously with alcohol and minocycline (10, 20, 30 and 40 mg/kg I.P, respectively) for 21 days. Group 7 received minocycline alone (40 mg/kg, i.p) for 21 days. Morris water maze (MWM) has been used to assess cognitive activity. Hippocampal neurodegenerative and histological parameters as well as cyclic AMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) levels were assessed. Alcohol impaired cognition, and concurrent therapy with various minocycline doses attenuated alcohol-induced cognition disturbances. Additionally, alcohol administration boosted lipid peroxidation and levels of glutathione in oxidized form (GSSG), tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and Bax protein, while decreased reducing type of glutathione (GSH), Bcl-2 protein, phosphorylated CREB, and BDNF levels in rat hippocampus. Alcohol also decreased the activity in the hippocampus of superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR). In comparison, minocycline attenuated alcohol-induced neurodegeneration; elevating expression levels of P-CREB and BDNF and inhibited alcohol induced histopathological changes in both dentate gyrus (DG) and CA1 of hippocampus. Thus, minocycline is likely to provide neuroprotection against alcohol-induced neurodegeneration through mediation of the P-CREB/BDNF signaling pathway.

Crocin may be useful to prevent or treatment of alcohol induced neurodegeneration and neurobehavioral sequels via modulation of CREB/BDNF and Akt/GSK signaling pathway

The neurodegeneration and neurobehavioral consequences of alcohol are serious and offering therapeutic approaches for management of these types of neurodegeneration is one of the main concerns of researchers in this manner. Alcohol-stimulated oxidative stress, apoptosis and inflammation, with modulation of involved signaling pathway in neuroprotection, was reported previously. Neuroprotective strategy for management of alcohol induced neurodegeneration through a new generation neuroprotective agent and based on modulation of some neuroprotective signaling pathway such as CREB/BDNF and Akt/GSK has always been superior to any other therapeutic interventions. Therefore, the introduction and development of potential new neuroprotective properties and clarification of their effects on major cell signaling such as CREB/BDNF and Akt/GSK is necessitated. During recent years, using new neuroprotective compounds with therapeutic probability for treatment of alcohol induced neuro-biochemical and neuro-behavioral malicious effects have been amazingly increased. Many previous studies have reported the neuroprotective roles of crocin (major active component of saffron) in multiple neurodegenerative events and diseases in animal model. But the role of crocin neuroprotective effects against alcohol induced neurodegeneration and neurobehavioral sequels and also role of CREB/BDNF and Akt/GSK in this manner remain unclear. Hence we hypothesized that by using crocin in alcohol dependent subject it would provide neuroprotection against alcohol induced neurodegeneration and neurobehavioral and probably can manage sequels of alcohol abuses. Also we hypothesized that crocin, via intonation of CREB/BDNF and Akt/GSK signaling pathway, can inhibit alcohol induced neurodegeneration. In this article, we tried to discuss our hypothesis regarding the possible role of crocin, as a potent neuroprotective agent, and also role of Akt/GSK and CREB/BDNF signaling pathway in treatment of alcohol induced neurodegeneration and neurobehavioral through its anti-inflammatory,anti-apoptotic, anti-oxidative stress and cognitive enhancer.

Alcohol use and dementia: a systematic scoping review

BACKGROUND

Alcohol use has been identified as a risk factor for dementia and cognitive decline. However, some patterns of drinking have been associated with beneficial effects.

METHODS AND RESULTS

To clarify the relationship between alcohol use and dementia, we conducted a scoping review based on a systematic search of systematic reviews published from January 2000 to October 2017 by using Medline, Embase, and PsycINFO. Overall, 28 systematic reviews were identified: 20 on the associations between the level of alcohol use and the incidence of cognitive impairment/dementia, six on the associations between dimensions of alcohol use and specific brain functions, and two on induced dementias. Although causality could not be established, light to moderate alcohol use in middle to late adulthood was associated with a decreased risk of cognitive impairment and dementia. Heavy alcohol use was associated with changes in brain structures, cognitive impairments, and an increased risk of all types of dementia.

CONCLUSION

Reducing heavy alcohol use may be an effective dementia prevention strategy.

Impact of acute alcohol consumption on lethality of suicide methods

BACKGROUND

The influence of acute alcohol consumption on the factors related to suicide remains understudied. Thus, the present study investigated the relationship between blood alcohol content (BAC) and the lethality of suicide methods.

METHODS

Autopsy data on 315 South Korean suicide completers with a positive BAC were collected from a nationwide pool between May 2015 and November 2015, and the methods were dichotomised as suicide methods of low lethality (SMLL; drug/chemical overdose and sharp objects, n=67) and suicide methods of high lethality (SMHL; everything else, n=243). BAC at the time of autopsy and various suicide-related factors of these two groups were compared with logistic regression analyses.

RESULTS

Compared to suicide completers with a BAC in the lowest range of 0.011-0.049%, suicide completers with a BAC in the range of 0.150-0.199% were more likely to use SMHL (odds ratio [OR]: 3.644, 95% confidence interval [CI]: 1.221-10.874). Additionally, the adoption of SMHL was significantly associated with the absence of a psychiatric illness (OR: 0.433, 95% CI: 0.222-0.843) and a younger age; the OR for high BAC among subjects in their 40s was 0.266 (95% CI: 0.083-0.856); in their 50s, 0.183 (95% CI: 0.055-0.615); and in their 60s, 0.057 (95% CI: 0.015-0.216).

CONCLUSIONS

The relationship between BAC and suicide method lethality was represented by a bell-shaped pattern in which suicide methods of high lethality were more likely to be used by suicide completers with mid-range BAC levels. The increased impulsivity and impairments in particular executive functions, including planning and organization, associated with acute alcohol use may influence the selection of a particular suicide method based on its lethality.

The frequency and influence of dementia risk factors in prodromal Alzheimer's disease

We investigated whether dementia risk factors were associated with prodromal Alzheimer's disease (AD) according to the International Working Group-2 and National Institute of Aging-Alzheimer's Association criteria, and with cognitive decline. A total of 1394 subjects with mild cognitive impairment from 14 different studies were classified according to these research criteria, based on cognitive performance and biomarkers. We compared the frequency of 10 risk factors between the subgroups, and used Cox-regression to examine the effect of risk factors on cognitive decline. Depression, obesity, and hypercholesterolemia occurred more often in individuals with low-AD-likelihood, compared with those with a high-AD-likelihood. Only alcohol use increased the risk of cognitive decline, regardless of AD pathology. These results suggest that traditional risk factors for AD are not associated with prodromal AD or with progression to dementia, among subjects with mild cognitive impairment. Future studies should validate these findings and determine whether risk factors might be of influence at an earlier stage (i.e., preclinical) of AD.