Definition matters: assessment of tolerance to the effects of alcohol in a prospective cohort study of emerging adults.

BACKGROUND AND AIMS: Tolerance to the effects of alcohol is an important element in the diagnosis of alcohol use disorders (AUD); however, there is ongoing debate about its utility in the diagnosis AUD in adolescents and young adults. This study aimed to refine the assessment of tolerance in young adults by testing different definitions of tolerance and their associations with longitudinal AUD outcomes. DESIGN: Prospective cohort study. SETTINGS: Australia. PARTICIPANTS: A contemporary cohort of emerging adults across Australia (n = 565, mean age = 18.9, range = 18-21 at baseline). MEASUREMENTS: Clinician-administered Structured Clinical Interview for DSM-IV Research Version (SCID-IV-RV) assessed for AUD criteria across five interviews, at 6-month intervals over 2.5 years. Tolerance definitions were operationalized using survey-type response (yes/no), clinician judgement (SCID-IV-RV), different initial drinking quantity and percentage increase thresholds and average heavy consumption metrics. AUD persistence was operationalized by the number of times AUD was present across the 2.5-year study period (n = 491), and new-onset AUD was operationalized as any new incidence of AUD during the follow-up period (n = 461). FINDINGS: The (i) SCID-IV-RV clinician judgement [odds ratio (OR) = 2.50, P = 0.005], (ii) an initial drinking quantity threshold of four to five drinks and 50% minimum increase (OR = 2.48, P = 0.007) and (iii) 50% increase only (OR = 2.40, P = 0.005) were the tolerance definitions more strongly associated with any new onset of AUD throughout the four follow-up time-points than other definitions. However, these definitions were not associated with persistent AUD (Ps > 0.05). Average heavy consumption definitions of tolerance were most strongly associated with persistent AUD (OR = 6.66, P = 0.001; OR = 4.65, P = 0.004) but not associated with new-onset AUD (Ps > 0.05). CONCLUSIONS: Initial drink and percentage change thresholds appear to improve the efficacy of change-based tolerance as an indicator for new-onset alcohol use disorder diagnosis in self-report surveys of young adults. When predicting persistent alcohol use disorder, average heavy consumption-based indicators appear to be a better way to measure tolerance than self-reported change-based definitions.

DSM-5 and ICD-11 alcohol use disorder criteria in young adult regular drinkers: Lifetime prevalence and age of onset.

BACKGROUND: Alcohol Use Disorder (AUD) is a significant contributor to global disease burden. AUD has a relatively early onset during young adulthood (Teesson et al., 2010). However, compared to AUD in adults, we have relatively little understanding of AUD in adolescents and emerging adults. METHODS: The RADAR study is a prospective cohort study designed to investigate the emergence of AUD in community-dwelling adolescents and emerging adults across Australia (age range = 18-21 at baseline). At 6 monthly intervals over 2.5 years, participants were interviewed regarding alcohol consumption and alcohol use disorder criteria by clinical psychologists using the SCID-IV-RV. This paper reports the baseline findings of the RADAR cohort. RESULTS: Proportions of lifetime criteria endorsement among regular drinkers varied considerably. Tolerance was the most endorsed criterion (50.3%), followed by Social Problems (10.4%) and Larger/Longer (9.0%). The median age of onset for most individual AUD criteria was 18 years of age. 18.4% of our cohort met DSM-5 AUD diagnosis in their lifetime to date, and 16.8% met ICD-11 dependence. When removing Tolerance from the AUD criteria, DSM-5 AUD lifetime prevalence reduced to 11.0%, and ICD-11 AUD lifetime prevalence fell to 7.1% in our cohort. CONCLUSIONS: Variable rates of criteria endorsement likely reflect both true differences in the experience of AUD criteria and methodological challenges in the assessment of AUD in an emerging adult age group. High rates of tolerance to the effects of alcohol, and relatively low rates of drinking larger/longer than intended are discussed considering methodological challenges in assessing these criteria in young adults.

The effect of daily aerobic cycling exercise on sleep quality during inpatient cannabis withdrawal: A randomised controlled trial.

Sleep disturbance is a common symptom encountered by cannabis-dependent individuals abstaining from cannabis use. In the present study, we investigated the effect of daily aerobic cycling exercise versus control stretching on sleep quality during inpatient cannabis withdrawal in treatment-seeking dependent cannabis users. The protocol incorporated three consecutive phases: a 4-Day (4-Night) (at-home) 'Baseline' phase, a 6-Day (5-Night) 'Treatment' phase (within a 7-Day inpatient hospital stay) and a 3-Day (4-Night) (at-home) 'Post-Treatment' phase. Participants performed 35 min of monitored activity per day during the Treatment phase. The intervention group (n = 19) cycled at ~60% aerobic capacity (VO2max ), while the control group (n = 12) performed a stretching routine. Objective sleep quality was measured nightly throughout the study using wrist actigraphy ratings of subjective sleep quality were also recorded during the Treatment phase. There were no group differences in sleep measures during the Baseline phase (all p > .05). Objective sleep onset latency increased from the Baseline to the Treatment phase in the control (stretching) group (p = .042). In contrast, the Cycling group exhibited improvements in sleep duration (p = .008) and sleep efficiency (p = .023) during the Treatment phase compared to the Baseline phase. Cycling also increased sleep duration (p = .005), decreased average wake bout (p = .040) and tended to increase sleep efficiency (p = .051) compared to stretching during the Treatment phase. Subjective sleep quality ratings did not differ between groups (p > .10). These preliminary findings suggest that moderate-intensity aerobic exercise may attenuate the sleep disturbances associated with cannabis withdrawal.

Gut feelings: A randomised, triple-blind, placebo-controlled trial of probiotics for depressive symptoms.

BACKGROUND: Depression is the leading cause of disability worldwide; with evidence suggesting that decreased gut barrier function and inflammation are correlated with depressive symptoms. We conducted a clinical trial to determine the effect of consumption of probiotic supplements (Winclove's Ecologic® Barrier) on depressive symptoms in a sample of participants with mild to severe depression. METHOD: 71 participants were randomly allocated to either probiotic or placebo, which was, consumed daily over eight weeks. Pre- and post-intervention measures of symptoms and vulnerability markers of depression as well as gut microbiota composition were compared. Clinical trial participants were also compared on psychological variables and gut microbiota composition to a non-depressed group (n = 20). RESULTS: All clinical trial participants demonstrated improvement in symptoms, suggesting non-specific therapeutic effects associated with weekly monitoring visits. Participants in the probiotic group demonstrated a significantly greater reduction in cognitive reactivity compared with the placebo group, particularly in the mild/moderate subgroup. Probiotics did not significantly alter the microbiota of depressed individuals, however, a significant correlation was found between Ruminococcus gnavus and one depression metric. LIMITATIONS: There was a high attrition rate, which may be attributed to weekly monitoring visits. Additionally, modulation of the gut microbiota may need more specific testing to distinguish subtle changes. CONCLUSIONS: While microbiota composition was similar between all groups, probiotics did affect a psychological variable associated with susceptibility to depression. Further research is needed to investigate how probiotics can be utilised to modify mental wellbeing, and whether they can act as an adjunct to existing treatments.