The ReCoDe addiction research consortium: Losing and regaining control over drug intake-Findings and future perspectives.

Substance use disorders (SUDs) are seen as a continuum ranging from goal-directed and hedonic drug use to loss of control over drug intake with aversive consequences for mental and physical health and social functioning. The main goals of our interdisciplinary German collaborative research centre on Losing and Regaining Control over Drug Intake (ReCoDe) are (i) to study triggers (drug cues, stressors, drug priming) and modifying factors (age, gender, physical activity, cognitive functions, childhood adversity, social factors, such as loneliness and social contact/interaction) that longitudinally modulate the trajectories of losing and regaining control over drug consumption under real-life conditions. (ii) To study underlying behavioural, cognitive and neurobiological mechanisms of disease trajectories and drug-related behaviours and (iii) to provide non-invasive mechanism-based interventions. These goals are achieved by: (A) using innovative mHealth (mobile health) tools to longitudinally monitor the effects of triggers and modifying factors on drug consumption patterns in real life in a cohort of 900 patients with alcohol use disorder. This approach will be complemented by animal models of addiction with 24/7 automated behavioural monitoring across an entire disease trajectory; i.e. from a naïve state to a drug-taking state to an addiction or resilience-like state. (B) The identification and, if applicable, computational modelling of key molecular, neurobiological and psychological mechanisms (e.g., reduced cognitive flexibility) mediating the effects of such triggers and modifying factors on disease trajectories. (C) Developing and testing non-invasive interventions (e.g., Just-In-Time-Adaptive-Interventions (JITAIs), various non-invasive brain stimulations (NIBS), individualized physical activity) that specifically target the underlying mechanisms for regaining control over drug intake. Here, we will report on the most important results of the first funding period and outline our future research strategy.

Associations of Menstrual Cycle and Progesterone-to-Estradiol Ratio With Alcohol Consumption in Alcohol Use Disorder: A Sex-Separated Multicenter Longitudinal Study.

OBJECTIVE: Alcohol use disorder (AUD) constitutes a critical public health issue and has sex-specific characteristics. Initial evidence suggests that progesterone and estradiol might reduce or increase alcohol intake, respectively. However, there is a need for a better understanding of how the menstrual cycle in females and the ratio of progesterone to estradiol in females and males influence alcohol use patterns in individuals with AUD. METHODS: In this sex-separated multicenter longitudinal study, the authors analyzed 12-month data on real-life alcohol use (from 21,460 smartphone entries), menstrual cycle, and serum progesterone-to-estradiol ratios (from 667 blood samples at four individual study visits) in 74 naturally cycling females and 278 males with AUD between 2020 and 2022, using generalized and general linear mixed modeling. RESULTS: Menstrual cycle phases were significantly associated with binge drinking and progesterone-to-estradiol ratio. During the late luteal phase, females showed a lower predicted binge drinking probability of 13% and a higher predicted marginal mean of progesterone-to-estradiol ratio of 95 compared with during the menstrual, follicular, and ovulatory phases (binge drinking probability and odds ratios vs. late luteal phase, respectively: 17%, odds ratio=1.340, 95% CI=1.031, 1.742; 19%, odds ratio=1.523, 95% CI=1.190, 1.949; and 20%, odds ratio=1.683, 95% CI=1.285, 2.206; difference in progesterone-to-estradiol ratios, respectively: -61, 95% CI=-105.492, -16.095; -78, 95% CI=-119.322, -37.039; and -71, 95% CI=-114.568, -27.534). In males, a higher progesterone-to-estradiol ratio was related to lower probabilities of binge drinking and of any alcohol use, with a 10-unit increase in the hormone ratio resulting in odds ratios of 0.918 (95% CI=0.843, 0.999) and 0.914 (95% CI=0.845, 0.988), respectively. CONCLUSIONS: These ecologically valid findings suggest that high progesterone-to-estradiol ratios can have a protective effect against problematic alcohol use in females and males with AUD, highlighting the progesterone-to-estradiol ratio as a promising treatment target. Moreover, the results indicate that females with AUD may benefit from menstrual cycle phase-tailored treatments.

Addiction Research Consortium: Losing and regaining control over drug intake (ReCoDe)-From trajectories to mechanisms and interventions.

One of the major risk factors for global death and disability is alcohol, tobacco, and illicit drug use. While there is increasing knowledge with respect to individual factors promoting the initiation and maintenance of substance use disorders (SUDs), disease trajectories involved in losing and regaining control over drug intake (ReCoDe) are still not well described. Our newly formed German Collaborative Research Centre (CRC) on ReCoDe has an interdisciplinary approach funded by the German Research Foundation (DFG) with a 12-year perspective. The main goals of our research consortium are (i) to identify triggers and modifying factors that longitudinally modulate the trajectories of losing and regaining control over drug consumption in real life, (ii) to study underlying behavioral, cognitive, and neurobiological mechanisms, and (iii) to implicate mechanism-based interventions. These goals will be achieved by: (i) using mobile health (m-health) tools to longitudinally monitor the effects of triggers (drug cues, stressors, and priming doses) and modify factors (eg, age, gender, physical activity, and cognitive control) on drug consumption patterns in real-life conditions and in animal models of addiction; (ii) the identification and computational modeling of key mechanisms mediating the effects of such triggers and modifying factors on goal-directed, habitual, and compulsive aspects of behavior from human studies and animal models; and (iii) developing and testing interventions that specifically target the underlying mechanisms for regaining control over drug intake.

Functional characterization of an oxytocin receptor gene variant (rs2268498) previously associated with social cognition by expression analysis in vitro and in human brain biopsy.

The oxytocin system plays a prominent role in social behavior across species, and numerous genetic studies in humans have reported associations between polymorphisms on the oxytocin receptor (OXTR) gene and phenotypes related to social cognition, affiliation, perspective taking, and sociability in healthy subjects and in patients with atypical social behavior, such as in autism spectrum disorders (ASD). Recently, the first study demonstrating altered agonist-induced OXTR internalization and recycling for the exonic variant rs35062132 emerged. Beside this, there has been no further demonstration of the functionality of the OXTR variants especially there does not exist any for the regulatory units. To address this gap in the literature, we tested the functionality of the promoter flanking single nucleotide polymorphism (SNP) rs2268498, which has proven an interesting candidate for predicting social behavior in recent association studies. Results of genetic expression analyses in human hippocampal tissue showed a twofold difference in messenger RNA transcription, dependent on the presence or absence of the C-allele. This finding was corroborated by cloning, i.e., in vitro reporter gene expression analysis after transfection of OXTR promoter plasmids into HEK-293 cells. Our results underline the importance of OXTR rs2268498 for genetic research in social behavior and ASD.

A prospective study of the standardized diagnostic evaluation of syncope.

AIMS: To evaluate the aetiology and the diagnostic yield of the standardized diagnostic work-up based on European Society of Cardiology guidelines in the syncope unit. METHODS AND RESULTS: A total of 501 patients (191 men and 310 women), mean age 65 years (44-75 years), were prospectively evaluated. They underwent initial evaluation (history, physical evaluation, and a 12-lead electrocardiogram) and subsequently targeted tests that differed according to suspected aetiology. Initial evaluation resulted in diagnosis in 155 patients--reflex syncope (93), arrhythmogenic syncope (62), and pacemaker malfunction (7). In 22 patients with solitary syncope, a diagnostic algorithm was stopped after initial evaluation. In 139 patients with organic heart disease, cardiac syncope was found in 83 patients and reflex syncope in 30 patients. In 185 patients without organic heart disease, reflex syncope was diagnosed in 127 patients, cardiac syncope in 30 patients, and vascular syncope in 2 patients. Vasovagal syncope was the most common type of syncope (43%), followed by bradyarrhythmias (25%), tachyarrhythmias (9%), and orthostatic hypotension (5%). Aetiology of syncope remained unknown in 11% of patients. Diagnostic yield of specific examinations was as follows: head-up tilt 52%, implantable loop recorder 51%, electrophysiologic study 33%, initial evaluation 31%, EKG Holter 12%, orthostatic test 10%, transoesophageal stimulation 9%, carotid sinus massage 4%, and echocardiography 2%. CONCLUSION: Standardized diagnostic evaluation determined the aetiology of syncope in 89% of patients. Diagnostic yield of specific diagnostic procedures was different. Initial evaluation resulted in diagnosis in one-third of patients.

Hemodynamic parameters and heart rate variability during a tilt test in relation to gene polymorphism of renin-angiotensin and serotonin system.

PURPOSE: The aim of the study was to evaluate the renin-angiotensin system and serotonin transporter gene polymorphisms in relation to hemodynamic parameters and heart rate variability during a head-up tilt test (HUT) in patients with vasovagal syncope. METHODS: DNA was collected from 191 patients (mean age 44+/-18 years, 61 men, 130 women). The following gene polymorphisms were determined in genomic DNA: angiotensin-converting enzyme insertion/deletion polymorphism (I/D ACE), angiotensinogen gene polymorphism (M 235), angiotensin II receptor type 1 (ATR1) polymorphism (A 11666C), and polymorphism of serotonin transporter gene (5HTTLPR).Heart rate variability during HUT was assessed in 5-minute intervals by low frequency, high frequency, standard deviation of the normal-to-normal (SDNN), and root mean square successive difference parameters. RESULTS: AA genotype of A 1166C polymorphism was associated with lower minimal systolic blood pressure (SBP) and diastolic blood pressure (DBP) during HUT compared with other genotypes (minimal SBP: AA 59.6+/-21,8, AC 79.9+/-22.7, CC 65.4+/-22.7 mmHg, P=0.007), (minimal DBP: AA 36.4+/-22.7, AC 52.3+/-22.9, CC 45.4+/-19.5 mmHg, P=0.007).AA genotype was also associated with higher SDNN compared to other genotypes in the early phase of HUT (SDNN in 5 minutes of tilt: AA 59.7+/-24.6, AC 50.6+/-20.6, CC 46.0+/-13.2, P=0.01) and at syncope occurrence (SDNN: AA 71.0+/-20.9, AC 58.2+/-17.9, CC 58+/-10, P=0.04) CONCLUSION: AA genotype of A 1166C polymorphism in the ATR1 gene may be associated with hypotension and decline in sympathetic tone during HUT. Its role in genetic predisposition to vasovagal syncope cannot be excluded.