Journal of Psychopharmacology

Adults aged [≥]65 years are increasingly using cannabis products. However, controlled pharmacokinetic and pharmacodynamic data on {Delta}9-tetrahydrocannabinol (THC) in this population are sparse, and remain limited to oral/oromucosal formulations. To characterize the acute pharmacokinetic and pharmacodynamic effects of oral and vaporized THC in healthy adults aged [≥]65, we conducted a two-arm, randomized, double-blind, placebo-controlled trial in which 20 participants (mean age 70.0, SD: 5.1 years) received oral (placebo, 5 mg, or 10 mg) or vaporized THC (placebo, 2 mg, or 4 mg) across three eight-hour sessions separated by [≥]72 hours. Outcomes included plasma pharmacokinetics, subjective drug effects, reinforcement value, cognitive performance, heart rate (HR), blood pressure (BP), and adverse events (AEs). Oral THC was associated with delayed, lower THC exposure (Tmax 60-90 min; Cmax 2.6-6.2 ng/mL), with 11-OH-THC concentrations approximately matching parent-THC; slow-rising subjective effects; no change in reinforcement value; no significant change in HR or BP; and no AEs. Vaporized THC was associated with rapid, THC-dominant exposure (Tmax 3 min; Cmax 24.6-53.8 ng/mL) and minimal 11-OH-THC concentrations; rapid-onset subjective effects; increased reinforcement value at 4 mg; and significant HR elevation peaking within 5 min, without significant BP change. Cognitive performance did not differ from placebo at any oral or vaporized THC dose. At vaporized THC 4 mg, two participants experienced five AEs. Oral and vaporized THC produce route-specific pharmacokinetic and pharmacodynamic profiles in adults aged [≥]65, including an increase in reinforcement value only after vaporization, and should therefore not be treated as interchangeable in risk assessment for older adults.

Background: Depression is a risk factor for overdose and is more commonly diagnosed among females. However, sex-differences in the association between depression, in isolation and in combination with substance use disorder (SUD), and overdose have not been examined at the population level in British Columbia (BC). This study described sex-and-age differences in associations between documented history of depression and/or SUD diagnoses and risk of fatal (FOD) and non-fatal overdose (NFOD). Methods: This study used linked administrative health data from the Provincial Health Services Authority Platform for Analytics and Data. The sample included BC residents aged 19-79 as of January 1st, 2015 (n=3,996,690). Exposures were classified as documented diagnosis history of 1) depression; 2) substance use disorder (SUD); 3) depression and SUD; and 4) neither condition, using physician billing and hospitalization records from 2010-2014. FOD (BC Coroners Service records) and NFOD (BC Emergency Health Services records) were ascertained from 2015 to 2024. Incidence rates per 10,000 person-years and unadjusted incidence rate ratios (IRRs) and 95% confidence intervals (CI) were estimated using Poisson regression, with neither diagnosis as reference, overall and stratified by sex and age. Results: There were 14,281 FOD (78.59% male) and 43,555 NFOD (69.45% male) cases. FOD incidence was higher among males overall; however, relative associations between diagnosis history and FOD risk were stronger among females. Depression diagnosis history was associated with a FOD IRR of 3.95 (CI: 3.56-4.38) among females and 2.46 (CI: 2.32-2.61) among males. IRRs for SUD and for depression and SUD were larger among females (108.07 [CI: 95.83-121.73] and 116.70 [CI: 106.51-127.96]) than males (26.69 [CI: 25.57-28.18] and 31.21 [CI: 29.81-32.67]). NFOD findings were similar but attenuated (depression IRR: 3.22 [CI: 3.08-3.38]) in females; 2.29 [CI: 2.21-2.37] in males). Conclusion: A documented history of depression and/or SUD was more strongly associated with FOD and NFOD risk among females, despite higher incidence overall among males. Future research should consider the potential role of other sociodemographic factors in explaining sex differences in associations between diagnosis history and overdose risk.

Background. Cannabidiol (CBD) products are sold in many forms for many purposes, but it is largely unknown which characteristics of real-world use relate to how users evaluate their experience. Methods. We analyzed an anonymous web-based survey of 377 CBD product users in Japan. We evaluated perceived-effect (0-5) and satisfaction (0-6) scores using main regression models of use frequency adjusted for age, sex, and body mass index. Separate supplementary models examined estimated daily CBD amount and other-cannabinoid co-use, purposes of use, or specific CBD amount-reporting status. Results. Use frequency was positively associated with perceived effects (B = 0.148, 95% CI 0.091 to 0.205) and satisfaction (B = 0.113, 95% CI 0.049 to 0.177; both p < 0.001). Estimated daily amount showed no clear association with either outcome after adjustment, whereas participants who reported specific milligram information had higher scores on both (B = 0.543, p < 0.001 and B = 0.559, p = 0.002). Amount-reporting status was associated with product form (tincture 48.5% vs 30.8%; smoking or inhalation 58.5% vs 75.7%; both FDR-adjusted p = 0.009), whereas no statistically significant group differences were found for age, sex, body mass index, use frequency, or sleep timing. Purposes of use and sleep-timing indicators showed no clear associations with the outcomes. Conclusions. Subjective evaluation of CBD use was more consistently related to how often CBD was used and whether a specific milligram amount was reported than to how much was reportedly taken, and amount-reporting status was related to product form. Specific CBD amount-reporting status may be a useful complementary dimension for characterizing real-world CBD use.

Monoamine oxidase B (MAO-B) is a high-density protein located mainly in astrocytes that influences mitochondrial function and transition to astrogliosis. MAO-B produces hydrogen peroxide while metabolizing non-serotonergic monoamines. Elevated MAO-B level is implicated in the pathophysiology of several common neuropsychiatric diseases. The aims are to examine the effect of treatment resistant major depressive episodes, sex, and antidepressant treatment on MAO-B total distribution volume ([11C]SL25.1188 VT), index of MAO-B level. [11C]SL25.1188 PET was applied in 95 adults (29 with MDE and no history of treatment-resistance (NTR-MDE), 26 with MDE and history of treatment-resistance (TRD), and 40 healthy control (HC)). A subset of NTR-MDE and TRD (n=13) were scanned before and after treatment with phenelzine, rasagiline, or duloxetine. [11C]SL25.1188 VT was higher in grey matter regions in females (10%, p<.001). [11C]SL25.1188 VT was also higher in prefrontal cortex in TRD compared to HC (23%, p<.001) and TRD compared to NTR-MDE (6%, p=.033). Duloxetine had minimal effect on [11C]SL25.1188 VT, but occupancy of rasagiline and phenelzine was ~94%. This study discovered sex differences in MAO-B level, which may explain sex differences in prevalence or trajectory of illnesses with greater MAO-B level like Alzheimer's disease, traumatic brain injury and major depressive disorder. Given our findings of greater MAO-B level in prefrontal cortex of TRD and its insensitivity to serotonin reuptake inhibition, combined with potential harm of highly elevated MAO-B level, development of MAO-B inhibitors could be considered for a subset of TRD. Rasagiline and phenelzine demonstrate similarly potent occupancy in vivo at clinical dosage.

Introduction: Self-rated health is an important patient-centred measure of health. The relationship between cannabis use and self-rated health has been previously studied, although with methodologic concerns which we aimed to address in this investigation. Methods: Propensity score weighted analyses of the National Health and Nutrition Examination Survey (NHANES) 2009-2018 were conducted. The primary exposure was self-reported cannabis use in the 30 days prior to survey response. The primary outcome was self-rated health measured on a five-level ordinal scale. Secondary outcomes included the number of days in the past months with: i) poor physical health, ii) poor mental health, and iii) activity limitations related to poor health. A weighted proportional odds regression model was used for the primary analysis and weighted zero-inflated negative binomial regression models were used for each secondary analysis. Results: Among 22,055 adults aged 20-59 responding to the NHANES cannabis questionnaire, 14.4% endorsed use in the past 30 days. After reweighting the sample to balance cannabis users and non-users across sociodemographic, medical, and lifestyle characteristics, there was no statistically significant association between recent cannabis use and higher levels of self-rated health (OR 0.90, 95% CI 0.80-1.01). Cannabis use was associated with poor mental health and activity limitations in the past month, but not poor physical health. Conclusions: Recent cannabis use was not associated with self-rated health but was associated with poor mental health and activity limitations in the past month. Cannabis users at risk of poor mental health should be connected with clinicians to help guide therapy.

Background and PurposeSerotonergic psychedelics affect behavior and physiology, but the relationships among these effects remain poorly understood. In rodents, the head-twitch response is used as a measure of psychedelic-like activity, yet it does not capture changes in physiological state or the performance of learned behaviors. Here, we investigated the acute effects of the 5-HT2A receptor agonist TCB-2 across several behavioral and physiological measures and examined how these effects were modified by pretreatment with the 5-HT2A receptor antagonist volinanserin. Experimental ApproachMice were tested in head-fixed and freely moving conditions. During a learned auditory trace-conditioning task, we measured licking, pupil area, eye position, and blinking. We measured locomotor activity in an open field and quantified head-twitch responses using a DeepLabCut-based method. To examine the contribution of 5-HT2A receptors, mice were pretreated with the 5-HT2A receptor antagonist volinanserin. Key ResultsTCB-2 caused pupil constriction without detectable changes in eye position or blinking when administered alone. TCB-2 also reduced licking at the highest dose, but the cue-locked temporal pattern of licking remained evident. In freely moving mice, TCB-2 reduced locomotor activity and produced a dose-dependent increase in head-twitch responses. Volinanserin partially attenuated TCB-2-induced pupil constriction and reduced head-twitch responses under some conditions, but it did not consistently prevent the other effects of TCB-2. Conclusions and ImplicationsTCB-2 produced distinct effects across physiological and behavioral measures rather than a uniform disruption of behavioral function. Pronounced pupil constriction and head-twitch responses occurred without detectable changes in eye position or blinking, while the temporal organization of conditioned licking was retained despite a reduction in its magnitude. The incomplete and variable effects of volinanserin preclude definitive conclusions about the receptor mechanisms underlying each response. Combining automated head-twitch detection with physiological and task-related measurements provides a broader framework for comparing the pharmacological profiles of serotonergic compounds. What is already knownO_LIClassical psychedelics produce characteristic effects primarily through serotonin 5-HT2A receptor activation. C_LIO_LIHead-twitch responses capture only one dimension of psychedelic-like drug action. C_LI What this study addsO_LITCB-2 reduced locomotion and licking while preserving the cue-locked pattern of conditioned licking. C_LIO_LIPupil constriction occurred without detectable changes in eye position or blinking. C_LI Clinical significanceO_LIMultidimensional phenotyping can distinguish the physiological and behavioral profiles of serotonergic compounds. C_LIO_LIComplementary measures may improve preclinical evaluation of emerging serotonergic therapeutics. C_LI

A toxic drug supply is responsible for a high number of deaths in Canada. Naloxone is a medication that can temporarily reverse opioid toxicity but cannot act on other drug classes. Take-home naloxone is a key public health response to the overdose crisis where people who may witness an overdose are educated on naloxone administration and overdose response. This study aims to investigate signs and substances associated with naloxone administration stratified by opioid contribution to death and substances detected where naloxone was administered but opioids did not contribute to death. This observational study of Canadian coroner and medical examiner files from 2016 to 2017 uses descriptive and chi square analyses to determine what signs were associated with having been administered naloxone among people for whom opioids contributed to death and what substances were associated with naloxone administration among people for whom no opioids were detected or contributed to the death. The study included 1,521 people who died of acute drug toxicity. Naloxone was administered to 45% of those who died and was administered in higher proportions when opioids contributed to death (50%) compared to when opioids did not (35%). Among people for whom opioids contributed to death, having been administered naloxone was associated with expected opioid toxicity signs of snoring/gurgling, altered consciousness, appearing asleep, and being cold. Among people for whom opioids did not contribute to death, detection of opioids or stimulants were significantly associated with naloxone administration. Further investigation into the barriers to naloxone administration should be conducted in order to improve drug toxicity response education.

Objective: Amphetamine (AMP) and its derivates are commonly prescribed for the management of attention-deficit/hyperactivity disorder (ADHD). This study aimed to 1) quantify AMP's transfer into human milk in lactating women receiving therapeutic doses and 2) contextualize infant exposure. Methods: Milk samples and dyad health histories of thirteen lactating women treated with varying doses of either mixed AMP, dextroamphetamine, or lisdexamfetamine were released for this study from the InfantRisk Human Milk Biorepository. Milk drug concentrations were quantified by validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) and used to calculate standard relative infant dose (RIDmat) and RID standardized to the defined daily dose (RIDDDD) of 15 mg AMP base. Results: Average milk concentrations (Cavg) of AMP base ranged from 23.3 to 297.0 ng/mL and increased linearly (R^2 = 0.92) with maternal daily dose. The RIDmat ranged 3.6-10.8% and RIDDDD ranged 1.4-21.8%. The fitted regression line crossed the 10% RIDDDD threshold at 1.17x DDD, with the upper 95% prediction limit crossing at 0.84x DDD. No adverse event reported by the mother-infant dyads were attributed to AMP exposure, notably including absence of reduced milk supply. Conclusions:The levels of AMP observed in human milk followed a dose predictable manner. The average patient was predicted to remain below the 10% RID DDD safety threshold at total daily doses at or below approximately 28 mg of mixed AMP salts or 59 mg of lisdexamfetamine. Ninety-five percent of patients were predicted to remain below the threshold at or below approximately 20 mg and 40 mg, respectively.

Purpose: Rhythmic regulation of human neurotransmission systems, particularly the mu-opioid receptor (MOR) and dopamine D2 receptor (D2R) signaling, remains poorly understood. Although prior studies indicate possible diurnal fluctuations in D2R signaling, potential existence of diurnal rhythms in MOR signaling has yet to be investigated. Furthermore, whether and how seasonal factors may override or interact with diurnal rhythms in either system remains unexplored. Decoding these temporal dynamics and their possible links to behavioral traits, such as anxiety, may improve mood regulation models and inspire rhythm-tailored interventions. Methods: Based on a historical PET database of healthy humans scanned with [11C]carfentanil (n = 188) and [11C]raclopride (n = 184), we investigated the diurnal patterns of MOR and D2R availability in the brain, using time-of-day (TOD) of scanning as predictor. Furthermore, we examined whether the TOD differences in receptor availability were modulated by seasonal differences in the daylength (D2R and MOR) and trait-anxiety (MOR). Results: The data revealed increased MOR and decreased D2R availability in the afternoon compared to the morning scans. Interaction with the seasonal effect was, however, observed only for MOR availability, spanning brain areas including anterior cingulate, dorsomedial and dorsolateral prefrontal cortex, insula and striatum. Besides, the diurnal variation of MOR availability in these regions was also sensitive to trait-anxiety levels. Conclusions: The current results reveal the diurnal patterns in opioidergic and dopaminergic neurotransmission with an opposing trajectory. Furthermore, the data highlight a unique role of the MOR system, mediating both types of rhythmic regulations, as well as behavioral traits.

Introduction There is evidence that regular and high-risk-consumption is more prevalent among adolescents with a lower socioeconomic family status (SES). Yet, the causes for the SES gap remain unclear. We postulate that SES inequalities in regular and high-risk cannabis use among adolescents are mediated by differences in risk perception and access. Methods This cross-sectional study used data from a survey to students aged 15-17 years from 35 European countries in 2019 (European School Survey Project on Alcohol and Drugs). We modelled current regular use ([&ge;]10 times in the past month) and past-year high-risk/problematic use as a function of maternal and paternal education, adjusting for age, sex, and country, then further adjusting for moderating variables: perceived cannabis availability and perceived risk of harm. Results Lower paternal education was related to both higher regular and high-risk use (OR: 1.55 (1.20-2.0) and OR: 1.77 (1.49-2.11), respectively. A similar pattern was observed with maternal educational level. Including mediating factors, perceived availability increased the likelihood of higher use among adolescents with lower SES, related to their lower perceived availability. In contrast, adjusting for risk perception, SES factors lost significance for regular use and reduced OR by 40 to 50% for high-risk use. Conclusion Results indicate that SES inequalities in perceived risk explain the SES gap in regular and high-risk cannabis use among the worse-off. Attention should be paid to policies that may foster the perception that cannabis is risky, which may aggravate dangerous consumption among the worse-off, contributing to larger SES inequalities.

Psilocybin is a psychedelic which has been shown to induce neural plasticity through activation of intracellular serotonergic 5-HT2A receptors. It also produces brain-wide changes in structural and functional connectivity and holds promise as a therapeutic compound for treating anxiety and depression. Despite links between psilocybin-induced plasticity, the psychedelic experience, and reduction in depressive symptoms, little is known about the effects of psilocybin on the function of the highly plastic hippocampus, a region crucial for memory whose dysfunction is linked to neural disorders such as depression and anxiety. In this study, we investigated the acute and lasting effects of psilocybin on rodent sharp-wave ripples (SWRs), transient high frequency oscillations observable in the hippocampal local field potential which are linked to memory consolidation. We found that a 10 mg/kg dose of psilocybin robustly decreased the peak SWR frequency and increased the duration of SWRs immediately following administration compared to control sessions the day before and after. Psilocybin also perturbed sleep architecture, resulting in a pronounced reduction in non-rapid eye movement (NREM) sleep which lasted for hours. Therefore, psilocybin could impact memory processing by modulating hippocampal SWRs.

Study Objectives: To characterize neural correlates of memory and emotion reactivity in individuals with insomnia disorder (INS) compared to good sleepers (GS) and to investigate associated short- and long-term changes following cognitive-behavioural therapy for insomnia (CBTi). Methods: This randomized controlled trial included 56 INS and 20 GS. At baseline, participants underwent resting-state and task-based functional magnetic resonance imaging, including working memory, emotion reactivity, and face-name associative memory tasks. They filled out sleep diaries and self-report questionnaires about sleep, cognition, and emotions, and underwent in-lab polysomnography. Subsequently, participants with INS were randomized to either the 3-month treatment group (TX) or wait-list control group (WL). Both TX and WL groups repeated baseline assessments at three months post-randomization and completed sleep diaries and questionnaires one year after finishing CBTi. Results: At baseline, the INS group reported higher insomnia severity, greater subjective cognitive impairment, and perceived sleep-related stimuli as more negative than GS. Contrasting with these subjective evaluations, no group differences were found in memory performance, task-based brain activity, or resting-state functional connectivity. At three months post-randomization and one-year follow-up, CBTi significantly improved subjective, but not objective, cognitive functioning and sleep in adults with INS. No significant treatment-related changes were observed in valence ratings of sleep images, task-based brain activity, or resting-state functional connectivity. Conclusions: Beyond its primary role in improving insomnia symptoms, CBTi may have long-term benefits for individuals with INS who experience concerns about their cognitive functioning, even in the absence of objective changes in neural processing of cognitive and emotional tasks.

Importance Anxiety of fluctuating severity is common in many psychiatric disorders. Few studies addressed factors determining individual differences in trajectories of the recovery phase, while their identification could inspire treatment innovation. Given the role of REM sleep in overnight alleviation of emotional distress, we here investigate whether individual differences in this overnight regulatory process matter for anxiety recovery. Objective To investigate whether individual differences in overnight alleviation of distress by REM sleep predict anxiety recovery rate. Design People tend to volunteer for intervention trials when fluctuating symptoms peak. This results in a significant recovery even in waitlist or control conditions. Leveraging this opportunity to recruit people prior to the recovery phase, in this cohort study, we utilized data from people who volunteered for optional sleep EEG and overnight distress assessment prior to their participation in an intervention trial (2021-2025). Anxiety severity was assessed at baseline and two months later. Setting Home-based assessment in the Netherlands. Participants Adults with insomnia alongside cross-threshold symptom severities of generalized anxiety disorder, social anxiety disorder, panic disorder, posttraumatic stress disorder, or borderline personality disorder (N = 223, 157 female [70.4%]; mean [SD] age, 45.7 [14.5] years; clinical diagnoses confirmed in 165 [74.0%]). Exposures Cognitive behavioral therapy for insomnia (CBT-I) or waitlist control. Main Outcomes and Measures Predicting 2-month anxiety improvement by individual differences in the strength of the effect of REM sleep on overnight distress alleviation at baseline. Results Within-subject mixed model analysis showed stronger overnight distress alleviation across nights with longer REM sleep (b = -0.011; 95% CI, -0.016 to -0.007; P < .001). Individual differences in the strength of REM-related distress alleviation predicted anxiety improvement after two months (b = -0.521; 95% CI, -0.854 to -0.188; P = .002), irrespective of treatment or waitlist control (interaction b = 0.011; 95% CI, -0.656 to 0.678; P = .97). Conclusions and Relevance Individual differences in the degree to which REM sleep drives overnight alleviation of distress predict the trajectory of anxiety recovery in people with clinically relevant psychiatric complaints. These findings suggest REM-related emotion regulation as a mechanism linking sleep physiology to anxiety recovery.

Background: Pavlovian-to-instrumental transfer (PIT) describes how conditioned cues shape instrumentally learned behavior and has been linked to cue-driven alcohol seeking and relapse in alcohol use disorder (AUD). Acute psychosocial stress is an established relapse risk factor that may amplify cue-driven motivational control. Whether acute stress modulates PIT behaviorally and neurally, and whether this differs in AUD, remains unclear. Methods: Within the TRR265 study, 109 participants (62 AUD, 46 controls (CON)) completed a within-subject, randomized, two-day PIT paradigm under Trier Social Stress Test and placebo conditions, with repeated salivary cortisol sampling across sessions. A subsample (n = 62; 34 AUD, 28 CON) underwent fMRI during the transfer phase. Results: A robust PIT effect emerged across groups, and acute stress significantly enhanced cue-driven response vigor (p = .034), with no AUD-specific behavioral effect. Exploratorily, cortisol responders showed stronger stress-related PIT enhancement than non-responders (p = .022). Neurally, PIT engaged the right amygdala during placebo. Acute stress induced less downregulation of PIT-related left amygdala activity in AUD than in CON (pFWE = .019), with no group difference during placebo. Conclusions: Acute psychosocial stress potentiated the motivational influence of non-drug-related conditioned cues on behavior irrespective of AUD status, identifying PIT as a candidate mechanism through which stress may promote alcohol-seeking behavior. Despite comparable behavioral effects, AUD was associated with blunted stress-induced downregulation of PIT-related amygdala activity, suggesting altered neural regulation of cue-driven processing whose relevance for future alcohol consumption and clinical outcome remains to be established.

Introduction Sleep is routinely assessed by psychiatric mental health nurses in acute inpatient wards, where overnight observation forms part of everyday clinical care. These records are repeatedly collected, but observational assessment and activity-based monitoring capture different aspects of sleep and may not be interchangeable. Aim To examine the agreement between actigraphy-based total sleep time and routine nursing sleep assessments in an acute psychiatric inpatient ward. Method This cross-sectional observational study included 94 patients admitted to an acute psychiatric ward. Participants wore wrist actigraphy devices for up to seven consecutive days while sleep duration was concurrently documented by nursing staff as part of routine care. Pearson correlation coefficients assessed linear association, and intraclass correlation coefficients (ICC) assessed agreement. Results Across all participants, nursing-assessed and actigraphy-based total sleep time showed a moderate linear association (Pearson r = 0.629) and good ICC (0.767). Bland-Altman analysis showed a mean bias of 0.20 hours, with 95% limits of agreement from -1.79 to 2.19 hours. Agreement varied across diagnostic groups and was strongest among patients with bipolar mania (r = 0.826; ICC = 0.886). Discussion Routine nursing sleep assessments showed little systematic bias relative to actigraphy at the group level, but wide limits of agreement indicate that the methods are not interchangeable for individual patients. Patient-reported sleep was not measured and should be included in future comparisons.

Recent shifts in the illicit fentanyl supply have led to widespread exposure to xylazine, yet the biological consequences of chronic fentanyl-xylazine co-exposure remain poorly understood. Here, we compared the behavioral and molecular effects of chronic exposures to fentanyl and xylazine both alone and in combination in male and female mice. Combined fentanyl-xylazine produced distinct, sex-dependent alterations in sleep architecture, including changes in NREMS recovery, REMS dynamics, and reduced sleep bout duration compared with fentanyl alone. The 2-adrenergic receptor antagonist yohimbine partially reversed these sleep alterations in a sex-dependent manner. Fentanyl-xylazine also exacerbated respiratory depression relative to fentanyl alone, particularly in males. In contrast, despite its prevalence in humans no skin lesions were observed. Molecular analyses revealed that fentanyl-xylazine co-administration leads to increased peripheral Fibroblast growth factor 21, a hepatokine linked to reduced opioid preference and alcohol consumption. Together, these findings demonstrate that xylazine substantially alters the physiological and neurobiological consequences of chronic fentanyl exposure in a sex-dependent manner, providing a preclinical framework for understanding the growing public health impact of fentanyl-xylazine co-use.

Background: Stimulant and non-stimulant medications increase fronto-striato-thalamic activation in youth with Attention-Deficit/Hyperactivity Disorder (ADHD). However, comparative effects of the more recently licensed stimulant lisdexamfetamine and non-stimulant guanfacine on functional magnetic resonance imaging (fMRI) correlates in ADHD are unknown. Methods: This exploratory randomised, placebo-controlled, double-blind, crossover study compared fMRI activation in youth with ADHD during a tracking stop-signal task (SST; N = 12), a working memory task (N-back; N = 11) and a sustained attention task (SAT; N = 10), after single clinical doses of either guanfacine extended-release, lisdexamfetamine, or placebo, with one-week washouts. Twenty-one demographically matched typically developing controls (TD) were assessed once to test for potential normalisation of case-control activation differences. Results: Region of interest analysis showed increased right caudate and putamen activation for lisdexamfetamine versus placebo during N-back and SAT, respectively. Both drugs shared an increase in left superior temporal activation versus placebo during N-back. In whole-brain analyses only lisdexamfetamine increased precuneus/posterior cingulate activation during SST versus guanfacine, and during N-back in pre- and postcentral and occipital cortices versus placebo. During SST, placebo-treated ADHD versus TD showed reduced putamen, insula, parietal and occipital activation that was potentially attenuated/normalised under lisdexamfetamine, while under guanfacine lingual gyrus underactivation remained, with additional precuneus and middle temporal underactivation. Also, only lisdexamfetamine improved and normalised SST performance. Conclusion: Lisdexamfetamine appears to have stronger and drug-exclusive upregulation and potential attenuation/normalisation effects than guanfacine on basal ganglia, posterior parieto-occipital and sensorimotor activations during ADHD-relevant executive function tasks with some shared putamen and superior temporal effects.

Background: Social difficulties in alcohol use disorder (AUD) have been linked to alterations in social cognition, including increased egocentric bias. Psychedelics such as psilocybin have been proposed to modulate self-related processing, but their effects on specific socio-cognitive mechanisms remain unclear. Methods: In this randomized controlled pilot study, recently detoxified individuals with AUD with persistent depressive symptoms completed a visual perspective-taking task before and after a psilocybin session (25 mg dose vs active placebo 1 mg psilocybin). Results: The 25 mg psilocybin group showed a significant reduction in egocentric bias and egocentric superiority on reaction times, with no effect on altercentric bias nor on accuracy. Between-group comparisons confirmed greater reductions in the high-dose relative to the low-dose group. The high-dose group reported more intense subjective psychedelic experiences, and greater subjective intensity was associated with lower egocentric superiority in accuracy. Conclusions: These findings provide preliminary evidence that psilocybin may selectively reduce egocentric interference in individuals with AUD, suggesting a decrease in egocentricity rather than enhanced sensitivity to others. Although replication in larger samples is needed, reduced egocentricity may represent one mechanism through which psilocybin influences social cognition in AUD. Clinical trial registration: ClinicalTrials.gov, https://clinicaltrials.gov/study/NCT06235411, NCT06235411.

Tobacco use is the leading preventable cause of death worldwide. Anxiety increases the risk for smoking, and smoking in turn increases the risk for anxiety disorders. There is therefore a need to identify interventions that reduce anxiety, in general and in the context of smoking, without producing sedation. Kava (Piper methysticum), a natural product with a long history of indigenous use, has been shown to have anxiolytic and calming effects and reduce nicotine withdrawal. The current study examined whether kava without the hepatotoxic flavokavains A and B (AB-free) could reduce anxiety-like behavior in mice repeatedly treated with nicotine. Male and female C57BL/6NCrl mice received either a control diet or an AB-free kava-supplemented diet and underwent two blocks of nicotine treatments. Mice underwent a first block of five every-other-day injections of nicotine (0.5 mg/kg) or saline, with open field testing after each injection, followed one week later by a nicotine challenge. A second block of injections was given using the same injection schedule, followed by a second challenge one week later, and two weeks afterward mice received a final challenge in a novel open field. During the first treatment block, AB-free kava significantly increased center time overall, an effect most pronounced in saline-treated animals, and increased locomotor activity, while nicotine decreased both measures. During the second challenge, nicotine reduced center time but not locomotor activity, and AB-free kava increased center time in saline-treated animals only. During the final challenge, nicotine reduced both measures, whereas AB-free kava increased center time regardless of nicotine treatment, and kava-treated animals also showed a near-significant increase in center entries. These results suggest that AB-free kava reduces anxiety-like behavior without inducing sedation but does not prevent nicotine-induced suppression of exploratory behavior.

Background: Risk of recurrent overdose is elevated following non-fatal overdose (NFOD) survival; timely interventions may reduce this risk. The specific role of mental health care in reducing recurrence is relatively underexplored, and post-overdose care has seldom been examined for sex differences. This study examined sex differences in the association between mental health-related primary care contacts following NFOD and overdose recurrence risk among people in British Columbia (BC) with a documented depression diagnosis history. Methods: This was a nested case-control study using linked administrative health data from the Provincial Health Services Authority Platform for Analytics and Data. The source cohort (n=7,022) comprised BC residents with a history of a documented depression diagnosis between 2010-2014 and at least one NFOD between 2015-2024. Cases experienced a recurrent overdose within one year of their index overdose; controls were selected using incidence density sampling. Exposures were the presence and number of mental health related primary care contacts in the 30- or 90-day window following the index overdose. Conditional logistic regression models were used to estimate adjusted incidence rate ratios (aIRRs) and confidence intervals (CI), overall and by sex. Secondary analyses were conducted using psychiatrist contacts. Results: Mental-health related primary care contact rates were low, with only 16.3% and 28.1% of the cohort with any contact within 30 and 90 days, respectively. Mental health-related primary care contacts were more strongly associated with reduced recurrence risk in the 30-day window (any contact aIRR: 0.57 [CI: 0.46-0.71]) than in the 90-day window (aIRR: 0.78 [CI: 0.65-0.94]). Any contact within 30 days was more strongly associated with lower recurrence risk among males (aIRR: 0.53 [CI: 0.39-0.72]) than among females (aIRR: 0.67 [CI: 0.50-0.91]), whereas associations between the number of contacts and recurrence risk were similar for males and females. Any psychiatrist contact within 30 days was more strongly associated with lower recurrence risk among females (aIRR: 0.50 [CI: 0.34-0.73]) than males (aIRR: 0.70 [0.52-0.95]). Discussion: Mental health-related care contacts shortly following NFOD were associated with lower overdose recurrence risk among people with a documented depression diagnosis history, with modest sex differences that varied by provider type. Low rates of contacts overall suggest gaps in access to care following NFOD, particularly among males. Further research on sex differences in post-overdose care are warranted.