Although some animal research suggests possible sex differences in response to THC exposure (e.g., Cooper & Craft, 2018), there are limited human studies. One study found that among individuals rarely using cannabis, when given similar amounts of oral and vaporized THC females report greater subjective intoxication compared to males (Sholler et al., 2020). However, in a study of daily users, females reported indistinguishable levels of intoxication compared to males after smoking similar amounts (Cooper & Haney, 2014), while males and females using 1–4x/week showed similar levels of intoxication, despite females having lower blood THC and metabolite concentrations (Matheson et al., 2020). It is important to elucidate sex differences in biological indicators of cannabis intoxication given potential driving/workplace implications as states increasingly legalize use. The current study examined if when closely matching males and females on cannabis use variables there are predictable sex differences in residual whole blood THC and metabolite concentrations, and THC/metabolites, subjective appraisals of intoxication, and driving performance following acute cannabis consumption.

The current study was part of a randomized clinical trial (Marcotte et al., 2022). Participants smoked ad libitum THC cigarettes and then completed driving simulations, blood draws, and subjective measures of intoxication. The main outcomes were the change in Composite Drive Score (CDS; global measure of driving performance) from baseline, whole blood THC, 11-OH-THC, and THC-COOH levels (ng/mL), and subjective ratings of how “high” participants felt (0 = not at all, 100 = extremely). For this analysis of participants receiving active THC, males were matched to females on 1) estimated THC exposure (g) in the last 6 months (24M, 24F) or 2) whole blood THC concentrations immediately post-smoking (23M, 23F).

When matched on THC exposure in the past 6 months (overall mean of 46 grams; p = .99), there were no sex differences in any cannabinoid/metabolite concentrations at baseline (all p > .83) or after cannabis administration (all p > .72). Nor were there differences in the change in CDS from pre-to-post-smoking (p = .26) or subjective “highness” ratings (p = .53). When matched on whole blood THC concentrations immediately after smoking (mean of 34 ng/mL for both sexes, p = .99), no differences were found in CDS change from pre-to-post smoking (p = .81), THC metabolite concentrations (all p > .25), or subjective “highness” ratings (p = .56). For both analyses, males and females did not differ in BMI (both p > .7).

When male/female cannabis users are well-matched on use history, we find no significant differences in cannabinoid concentrations following a mean of 5 days of abstinence, suggesting that there are no clear biological differences in carryover residual effects. We also find no significant sex differences following ad libitum smoking in driving performance, subjective ratings of “highness,” nor whole blood THC and metabolite concentrations, indicating that there are no biological differences in acute response to THC. This improves upon previous research by closely matching participants over a wider range of use intensity variables, although the small sample size precludes definitive conclusions.

Treatments for MDD that can improve both overall depressive and anhedonic symptoms are urgently needed.

AXS-05 (dextromethorphan-bupropion) is a novel, oral, investigational NMDA receptor antagonist with multimodal activity being developed for MDD. The dextromethorphan component of AXS-05 is an NMDA receptor antagonist and a sigma-1 receptor agonist. The bupropion component of AXS-05 serves primarily to increase the bioavailability of dextromethorphan.

To evaluate the effect of AXS-05 in improving anhedonic symptoms in MDD.

GEMINI (N=327) was a randomized, double-blind, placebo-controlled, 6-week study, which randomized adults with MDD to AXS-05 (dextromethorphan HBr 45 mg- bupropion HCl 105 mg) or placebo, twice daily. The primary endpoint was change from baseline in the MADRS total score at Week 6. A post-hoc analysis was conducted to determine the impact of AXS-05 versus placebo on the 5-item MADRS anhedonia subscale (MAS).

Baseline MAS scores were 19.8 and 19.6 in the AXS-05 and placebo group, respectively. At Week 1, AXS-05 treatment resulted in a significant mean reduction from baseline in the MAS score of 4.44 versus 2.69 points for placebo (p< 0.001). At Week 6, the mean reduction from baseline in the MAS was 9.70 for AXS-05 compared to 7.22 for placebo (p=0.001). Response rates (≥ 50% MAS improvement) were significantly greater for AXS-05 compared to placebo at Week 1 (p< 0.001) and at every time point thereafter.

Treatment with AXS-05 was generally safe and well tolerated. The most common adverse events being dizziness, nausea, headache, diarrhea, somnolence, and dry mouth.

Treatment with AXS-05 rapidly and significantly reduced anhedonic symptoms as well as overall depressive symptoms.

Axsome Therapeutics

Catatonia, a severe neuropsychiatric syndrome, has few studies of sufficient scale to clarify its epidemiology or pathophysiology. We aimed to characterise demographic associations, peripheral inflammatory markers and outcome of catatonia.

Electronic healthcare records were searched for validated clinical diagnoses of catatonia. In a case–control study, demographics and inflammatory markers were compared in psychiatric inpatients with and without catatonia. In a cohort study, the two groups were compared in terms of their duration of admission and mortality.

We identified 1456 patients with catatonia (of whom 25.1% had two or more episodes) and 24 956 psychiatric inpatients without catatonia. Incidence was 10.6 episodes of catatonia per 100 000 person-years. Patients with and without catatonia were similar in sex, younger and more likely to be of Black ethnicity. Serum iron was reduced in patients with catatonia [11.6 v. 14.2 μmol/L, odds ratio (OR) 0.65 (95% confidence interval (CI) 0.45–0.95), p = 0.03] and creatine kinase was raised [2545 v. 459 IU/L, OR 1.53 (95% CI 1.29–1.81), p < 0.001], but there was no difference in C-reactive protein or white cell count. N-Methyl-d-aspartate receptor antibodies were significantly associated with catatonia, but there were small numbers of positive results. Duration of hospitalisation was greater in the catatonia group (median: 43 v. 25 days), but there was no difference in mortality after adjustment.

In the largest clinical study of catatonia, we found catatonia occurred in approximately 1 per 10 000 person-years. Evidence for a proinflammatory state was mixed. Catatonia was associated with prolonged inpatient admission but not with increased mortality.

To examine associations between diet and risk of developing gastro-oesophageal reflux disease (GERD).

Prospective cohort with a median follow-up of 15·8 years. Baseline diet was measured using a FFQ. GERD was defined as self-reported current or history of daily heartburn or acid regurgitation beginning at least 2 years after baseline. Sex-specific logistic regressions were performed to estimate OR for GERD associated with diet quality scores and intakes of nutrients, food groups and individual foods and beverages. The effect of substituting saturated fat for monounsaturated or polyunsaturated fat on GERD risk was examined.

Melbourne, Australia.

A cohort of 20 926 participants (62 % women) aged 40–59 years at recruitment between 1990 and 1994.

For men, total fat intake was associated with increased risk of GERD (OR 1·05 per 5 g/d; 95 % CI 1·01, 1·09; P = 0·016), whereas total carbohydrate (OR 0·89 per 30 g/d; 95 % CI 0·82, 0·98; P = 0·010) and starch intakes (OR 0·84 per 30 g/d; 95 % CI 0·75, 0·94; P = 0·005) were associated with reduced risk. Nutrients were not associated with risk for women. For both sexes, substituting saturated fat for polyunsaturated or monounsaturated fat did not change risk. For both sexes, fish, chicken, cruciferous vegetables and carbonated beverages were associated with increased risk, whereas total fruit and citrus were associated with reduced risk. No association was observed with diet quality scores.

Diet is a possible risk factor for GERD, but food considered as triggers of GERD symptoms might not necessarily contribute to disease development. Potential differential associations for men and women warrant further investigation.

Catatonia is a frequent, complex and severe identifiable syndrome of motor dysregulation. However, its pathophysiology is poorly understood.

We aimed to provide a systematic review of all brain imaging studies (both structural and functional) in catatonia.

We identified 137 case reports and 18 group studies representing 186 individual patients with catatonia. Catatonia is often associated with brain imaging abnormalities (in more than 75% of cases). The majority of the case reports show diffuse lesions of white matter, in a wide range of brain regions. Most of the case reports of functional imaging usually show frontal, temporal, or basal ganglia hypoperfusion. These abnormalities appear to be alleviated after successful treatment of clinical symptoms. Structural brain magnetic resonance imaging studies are very scarce in the catatonia literature, mostly showing diffuse cerebral atrophy. Group studies assessing functional brain imaging after catatonic episodes show that emotional dysregulation is related to the GABAergic system, with hypoactivation of orbitofrontal cortex, hyperactivation of median prefrontal cortex, and dysconnectivity between frontal and motor areas.

In catatonia, brain imaging is abnormal in the majority of cases, and abnormalities more frequently diffuse than localised. Brain imaging studies published so far suffer from serious limitations and for now the different models presented in the literature do not explain most of the cases. There is an important need for further studies including a better clinical characterisation of patients with catatonia, functional imaging with concurrent catatonic symptoms and the use of novel brain imaging techniques.

Emergency Medical Services (EMS) systems have developed protocols for prehospital activation of the cardiac catheterization laboratory for patients with suspected ST-elevation myocardial infarction (STEMI) to decrease first-medical-contact-to-balloon time (FMC2B). The rate of “false positive” prehospital activations is high. In order to decrease this rate and expedite care for patients with true STEMI, the American Heart Association (AHA; Dallas, Texas USA) developed the Mission Lifeline PreAct STEMI algorithm, which was implemented in Los Angeles County (LAC; California USA) in 2015. The hypothesis of this study was that implementation of the PreAct algorithm would increase the positive predictive value (PPV) of prehospital activation.

This is an observational pre-/post-study of the effect of the implementation of the PreAct algorithm for patients with suspected STEMI transported to one of five STEMI Receiving Centers (SRCs) within the LAC Regional System. The primary outcome was the PPV of cardiac catheterization laboratory activation for percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG). The secondary outcome was FMC2B.

A total of 1,877 patients were analyzed for the primary outcome in the pre-intervention period and 405 patients in the post-intervention period. There was an overall decrease in cardiac catheterization laboratory activations, from 67% in the pre-intervention period to 49% in the post-intervention period (95% CI for the difference, -14% to -22%). The overall rate of cardiac catheterization declined in post-intervention period as compared the pre-intervention period, from 34% to 30% (95% CI, for the difference -7.6% to 0.4%), but actually increased for subjects who had activation (48% versus 58%; 95% CI, 4.6%-15.0%). Implementation of the PreAct algorithm was associated with an increase in the PPV of activation for PCI or CABG from 37.9% to 48.6%. The overall odds ratio (OR) associated with the intervention was 1.4 (95% CI, 1.1-1.8). The effect of the intervention was to decrease variability between medical centers. There was no associated change in average FMC2B.

The implementation of the PreAct algorithm in the LAC EMS system was associated with an overall increase in the PPV of cardiac catheterization laboratory activation.