Pharmacological enhancing agents targeting cognition in patients with alcohol-induced neurocognitive disorders: A systematic review

Efficacy and safety of short-term edaravone or nerve growth factor add-on therapy for alcohol-related brain damage: A multi-centre randomised control trial

AIMS

To measure the therapeutic effect of an anti-oxidant, edaravone (EDV), or neurotrophic treatment with nerve growth factor (NGF) as an add-on treatment for alcohol-related brain damage (ARBD).

DESIGN

Multi-centre, randomised, single-blinded, comparative clinical trial.

SETTING AND PARTICIPANTS

One hundred and twenty-two inpatients recruited from seven hospitals in different regions of China, all diagnosed with ARBD and aged 18 to 65 years old; among them, only two were female.

INTERVENTION AND COMPARATOR

Patients were randomly assigned to receive one of three treatments for 2 weeks: 40 patients, treatment as usual (TAU: a combination of intramuscular injections of thiamine, intravenous infusions of other B vitamins with vitamin C and oral medication with vitamin E per day); 40, EDV add-on treatment to TAU (intravenous infusion with 30 mg of EDV twice per day); and 42, NGF add-on treatment to TAU (intramuscular injection of 20 μg of NGF per day). The patients underwent follow-up for 24 weeks.

MEASUREMENTS

The primary outcome was the composite score of executive cognitive function in the 2nd week after treatment, which was measured as the mean of the Z scores of the assessments, including the digit symbol substitute test (DSST), digit span memory test-forward (DST-F), digit span memory test-reverse (DST-R) and space span memory test (SSMT). The secondary outcomes were the composite scores at later follow-ups, the score for each component of cognitive function, global cognitive function measured by the Montreal Cognitive Assessment (MoCA), craving for alcohol and the safety of the therapies.

FINDINGS

EDV add-on treatment improved the composite score of executive cognitive function better than TAU in the 2nd week (adjusted mean difference: 0.24, 95% confidence interval 0.06 to 0.41; P = 0.008), but NGF add-on treatment did not (adjusted mean difference: 0.07, 95% confidence interval -0.09 to 0.24; P = 0.502). During the follow-up to 24 weeks, EDV add-on treatment improved the composite score of executive cognitive function and DST-R score better than TAU (both P < 0.01). Craving for alcohol was relieved in all three groups. No severe adverse events were observed.

CONCLUSION

The short-term addition of edaravone to supplementary therapy treatment for alcohol-related brain damage (ARBD) improved executive cognitive function in patients with ARBD.

Sensitivity of Hypocretin System to Chronic Alcohol Exposure: A Human and Animal Study

Human heroin addicts and mice administered morphine for a 2 week period show a greatly increased number of hypothalamic hypocretin (Hcrt or orexin) producing neurons with a concomitant reduction in Hcrt cell size. Male rats addicted to cocaine similarly show an increased number of detectable Hcrt neurons. These findings led us to hypothesize that humans with alcohol use disorder (AUD) would show similar changes. We now report that humans with AUD have a decreased number and size of detectable Hcrt neurons. In addition, the intermingled melanin concentrating hormone (MCH) neurons are reduced in size. We saw no change in the size and number of tuberomammillary histamine neurons in AUD. Within the Hcrt/MCH neuronal field we found that microglia cell size was increased in AUD brains. In contrast, male rats with 2 week alcohol exposure, sufficient to elicit withdrawal symptoms, show no change in the number or size of Hcrt, MCH and histamine neurons, and no change in the size of microglia. The present study indicates major differences between the response of Hcrt neurons to opioids and that to alcohol in human subjects with a history of substance abuse.

Therapeutic strategies of small molecules in the microbiota-gut-brain axis for alcohol use disorder

The microbiota-gut-brain axis (MGBA) is important in maintaining the structure and function of the central nervous system (CNS) and is regulated by the CNS environment and signals from the peripheral tissues. However, the mechanism and function of the MGBA in alcohol use disorder (AUD) are still not completely understood. In this review, we investigate the underlying mechanisms involved in the onset of AUD and/or associated neuronal deficits and create a foundation for better treatment (and prevention) strategies. We summarize recent reports focusing on the alteration of the MGBA in AUD. Importantly, we highlight the properties of small-molecule short-chain fatty acids (SCFAs), neurotransmitters, hormones, and peptides in the MGBA and discusses their usage as therapeutic agents against AUD.

Pharmacological compounds targeting emotional cognition in alcohol use disorder: A systematic review

Non-emotional (e.g., executive functions) and emotional cognitive (e.g., facial emotion recognition) impairments are a well-known aspect of alcohol use disorder (AUD). These deficits may impede on treatment outcomes, increase the risk of relapse, and lead to socio-occupational disabilities. Previous systematic reviews have examined the effectiveness of cognitive enhancing pharmacological agents (CEPAs) targeting non-emotional, but not emotional, cognition in AUD. Our aim was to systematically review the effectiveness of CEPAs targeting emotional cognition in subclinical and clinical AUD populations. A qualitative synthesis of controlled trials was conducted, and the studies were assessed for risk of bias. Eight studies were eligible (15 ≤ ns ≤ 143), and they all had a moderate risk of bias. Modafinil and nalmefene were the most examined agents, with the findings suggesting a potential beneficial effect of the agents on implicit emotional domains (i.e., reward processing). Methodological shortcomings and heterogeneous findings across the studies do not allow inferences about the effectiveness of these compounds in AUD. Future studies should examine CEPAs targeting emotional cognition in more detail.