OOIR: Observatory of International Research

Papers

(The TQCC of Journal of Psychopharmacology is 9. The table below lists those papers that are above that threshold based on CrossRef citation counts [max. 250 papers]. The publications cover those that have been published in the past four years, i.e., from 2022-05-01 to 2026-05-01.)

Article	Citations
Cannabimimetic and discriminative stimulus effects of hexahydrocannabinols in mice	196
Effects of initial nicotine exposure on cognition and nicotine reinforcement among non-smoking young adults with and without attention deficit hyperactivity disorder	137
The chronic effects of a combination of herbal extracts (Euphytose^®) on psychological mood state and response to a laboratory stressor: A randomised, placebo-controlled, double blind study	125
Science, safety and education: Informing the psychedelic treatment of psychiatric disorders	93
Co-use of psychedelics with other substances: Findings from the global psychedelic survey	70
Circadian rhythmicity in prepulse inhibition of the acoustic startle response: A study of chronotype and time-of-day effects in young healthy adults	57
Meditating on psychedelics. A randomized placebo-controlled study of DMT and harmine in a mindfulness retreat	54
The effects of the PDE4 inhibitor roflumilast on cognitive performance after a cerebrovascular accident: a double-blind randomized placebo-controlled trial with an open label extension (ROSTMEMA)	53
The revival of the psychedelic experience scale: Revealing its extended-mystical, visual, and distressing experiential spectrum with LSD and psilocybin studies	51
Preliminary evidence that serum interleukin-6 is a candidate biomarker of response to esketamine in treatment-resistant depression	51
Off the RADAR; questions regarding the trial protocol of a randomised controlled trial of antipsychotic reduction and discontinuation	51
Deaths related to the use of diarylethylamines, with a focus on the United Kingdom: A systematic review and case series report	50
Award winning abstracts presented at the 15 ^th Annual International College of Mental Health Pharmacy (CMHP) Conference, Liverpool, UK, on 10	50
Effectiveness of vortioxetine in elderly patients with major depressive disorder in real-world clinical practice: Results from the RELIEVE study	47
Interactions between classic psychedelics and serotonergic antidepressants: Effects on the acute psychedelic subjective experience, well-being and depressive symptoms from a prospective survey study	46
Psychedelics and the ‘inner healer’: Myth or mechanism?	45
Proportion of Antipsychotics with CYP2D6 Pharmacogenetic (PGx) Associations Prescribed in an Early Intervention in Psychosis (EIP) Cohort: A Cross-Sectional Study	45
The D1/D2-like receptor antagonist flupentixol and the D2-like receptor antagonist L-741626 decrease operant responding for nicotine and food and locomotor activity in male and female rats	43
Relationship between change in social evaluation learning and mood in early antidepressant treatment: A prospective cohort study in primary care	41
Solriamfetol improves daily fatigue symptoms in adults with myalgic encephalomyelitis/chronic fatigue syndrome after 8 weeks of treatment	41
Pharmaco-fUS in cognitive impairment: Lessons from a preclinical model	41
The effects of antenatal depression and SSRI exposure on children: A systematic review	40
Associations between regular cannabis use and brain resting-state functional connectivity in adolescents and adults	39
A reflection on paradigmatic tensions within the FDA advisory committee for MDMA-assisted therapy	36
Comparison of average time-to-relapse following ECT versus ketamine – A systematic review	36

A framework for assessment of adverse events occurring in psychedelic-assisted therapies	36
An α7 nAChR approach for the baseline-dependent modulation of deviance detection in schizophrenia: A pilot study assessing the combined effect of CDP-choline and galantamine	36
Cannabidiol in clinical and preclinical anxiety research. A systematic review into concentration–effect relations using the IB-de-risk tool	35
Psychedelic research – Going global	34
Not too quick on “Debunking the myth of ‘Blue Mondays’”	33
Haloperidol dopamine receptor occupancy and antagonism correspond to delirium agitation scores and EPS risk: A PBPK-PD modeling analysis	33
Serotonin release by parachloroamphetamine in rats with high and low sociability: High prefrontal release capacity in sociable females	32
Every prescription is a prediction	30
Corrigendum: Is psychedelic use associated with cancer? Interrogating a half-century-old claim using contemporary population-level data	30
The therapeutic readiness of probiotics in major depressive disorder: A systematic review of randomised controlled trials	30
Effects of LSD, DMT and psilocybin on cognitive and psychological functions: A systematic review of the literature	29
The empathogen 3,4-methylenedioxymethamphetamine, but not methamphetamine, increases feelings of global trust	28
Ketamine use in a large global sample: Characteristics, patterns of use and emergency medical treatment	28
Postpartum depression: A role for psychedelics?	28
The New Zealand drug harms ranking study: A multi-criteria decision analysis	27
Elevated C-reactive protein among symptomatic youth with bipolar disorder	27
What are set and setting: Reducing vagueness to improve research and clinical practice	27
The 5-HT1A receptor biased agonists, NLX-204 and NLX-101, like ketamine, elicit rapid-acting antidepressant activity in the rat chronic mild stress model via cortical mechanisms	27
Voluntary nicotine consumption and reward in a subset of diversity outbred founder strains	27
Mind the gap! Addressing unresolved aspects of abuse potential evaluation and scheduling of classic and novel psychedelic drugs	26
Antipsychotic co-medication and treatment response to rTMS and iTBS in depression: Data from clinical records from two independent clinical sites	26
Psychedelic-assisted psychotherapy: The need to monitor adverse events	26
A randomised double-blind, placebo-controlled trial of pramipexole in addition to mood stabilisers for patients with treatment-resistant bipolar depression (the PAX-BD study)	25
Associations of antidepressants and antipsychotics with lipid parameters: Do CYP2C19 / CYP2D6 genes play a	25
Impact of psychedelics on craving in addiction: A systematic review	24
The low risk for early renal damage during lithium treatment has not changed over time	23
Ketamine/esketamine pharmacotherapy for treatment of anxiety disorders and anxiety symptoms in depression: Systematic review	23
Statistical limitations of the claimed dose–response in “Dose–response efficacy and safety of lumateperone in bipolar depression: A preliminary meta-analysis of randomized controlled trials”	23
A phase 1b study to investigate the potential interactions between ASP8062 and buprenorphine/naloxone in patients with opioid use disorder	21
Wistar Kyoto rats exhibit decreased serotonin neuronal firing and increased norepinephrine burst activity but dampened hippocampal α₂-adrenoceptor sensitivity	21
Effect of alcohol coadministration on the pharmacodynamics, pharmacokinetics, and safety of lemborexant: A randomized, placebo-controlled crossover study	21
The helioscope effect: A new framework for evaluating trauma-related memory processing in psychedelic experiences	21
Associations between MDMA/ecstasy use and physical health in a U.S. population-based survey sample	20
Drug–drug interactions involving classic psychedelics: A systematic review	20
The mechanism of action of clozapine	20
Associations between paraoxonase-1 activity and therapeutic drug monitoring indicators in schizophrenia patients treated with olanzapine: A cross-sectional study	20
Oral esketamine for patients with severe treatment-resistant depression: Effectiveness, safety, and tolerability of a six-week open-label treatment program	20
Effect of CannEpil ^® on simulated driving performance and co-monitoring of ocular activity: A randomised controlled trial	19
Psilocybin for clinical indications: A scoping review	19
Can psychedelics enhance group psychotherapy? A discussion on the therapeutic factors	19
Factor analysis of treatment acceptability in double-blind randomised clinical trial of home-based transcranial direct current stimulation in major depression and in healthy individuals	19
Hippocampal phase precession is preserved under ketamine, but the range of precession across a theta cycle is reduced	19
Eight-week antidepressant treatment effects on connectome gradient in first-episode drug-naïve patients with major depressive disorder	18
The antidepressant effect and safety of non-intranasal esketamine: A systematic review	18
Evaluation of the sedative-motor effects of novel GABAkine imidazodiazepines using quantitative observation techniques in rhesus monkeys	18
A critical evaluation of QIDS-SR-16 using data from a trial of psilocybin therapy versus escitalopram treatment for depression	18
Evidence-based guidelines for the interpretation of the 9-item Concise Health Risk Tracking – Self-Report (CHRT-SR₉) measure of suicidal risk	18
Association of clozapine treatment and rate of methamphetamine or amphetamine relapses and abstinence among individuals with concurrent schizophrenia spectrum and amphetamine use disorder: A retrospec	18
A three-stage strategy for conducting an experimental investigation: A recommendation to improve the reproducibility of reported conclusions	17
Examining mystical experiences as a predictor of psilocybin-assisted psychotherapy for treatment-resistant depression	17

Modafinil: A closer look at its theoretical toxicological potential	17
Validation of ratings on the six-item Positive and Negative Syndrome Scale obtained via the Simplified Negative and Positive Symptoms Interview among outpatients with schizophrenia	17
Pivotal role of orexin signaling in the posterior paraventricular nucleus of the thalamus during the stress-induced reinstatement of oxycodone-seeking behavior	17
The effects of reserpine on depression: A systematic review	17
Differences in social brain function in autism spectrum disorder are linked to the serotonin transporter: A randomised placebo-controlled single-dose crossover trial	16
Escitalopram and functional connectivity in major depressive disorder: A systematic review	16
Efficacy and safety of pharmacological and non-pharmacological interventions for antipsychotic-induced weight gain in individuals with schizophrenia: A systematic review and network meta-analysis of 5	16
Is lack of goal-conflict-specific rhythmicity a biomarker for treatment resistance in generalised anxiety but not social anxiety or major depression?	16
Assessment of the reporting of harms in systematic reviews focused on hallucinogens: A cross-sectional study	16
Blackcurrant ( Ribes nigrum L.) improves cholinergic signaling and protects against chronic Scopolamine-induced memory impairment in mice	15
The impact of antidepressant use on MDMA fatalities: A matched case-control study using a post-mortem database	15
Exploring the efficacy and safety of a novel standardized ashwagandha (Withania somnifera) root extract (Witholytin®) in adults experiencing high stress and fatigue in a randomized, double-blin	15
Negative affect interacts with perceptual affective biases	15
Mechanisms of psilocybin on the treatment of posttraumatic stress disorder	15
Chronic Cannabis users exhibit altered oscillatory dynamics and functional connectivity serving visuospatial processing	15
Examining the role of systemic chronic inflammation in diet and sleep relationship	14
Episodic foresight is impaired following acute alcohol intoxication	14
Predictors of therapeutic response to psychedelic-assisted therapy: A systematic review	14
Is microdosing a placebo? A rapid review of low-dose LSD and psilocybin research	14
Older adults in psychedelic-assisted therapy trials: A systematic review	14
Effects of psilocybin on personality, psychiatric symptoms, and values: Exploring mediating effects of the acute psychedelic experience	13
We need to talk: The urgent conversation on chronic pain, mental health, prescribing patterns and the opioid crisis	13
Efficacy and safety of supraphysiologic doses of levothyroxine for patients with bipolar depression in adults: A systematic review	13
Revisiting monoamine oxidase inhibitors: A potential dual-action therapy for patients with prostate cancer and comorbid depression?	13
The role of psychopharmacology and cognitive neuroscience in understanding the brain in the treatment of psychiatric disorders and neurological diseases for the benefit of society	13
Subjectively reported sleep improvement with antipsychotic medications in clinical practice: A systematic review, meta-analysis and meta-regression of moderating factors	13
Risk of major congenital malformations and heart defects in pregnancies exposed to first-trimester drugs for depression and co-medications	13
Effects of cannabidiol on behavioral and psychological symptoms of vascular dementia: A randomized, double-blind, placebo-controlled clinical trial	13
Significance of mammalian N, N-dimethyltryptamine (DMT): A 60-year-old debate	13
The CannTeen Study: Cannabis use disorder, depression, anxiety, and psychotic-like symptoms in adolescent and adult cannabis users and age-matched controls	12
Long-term neurocognitive side effects of MDMA in recreational ecstasy users following sustained abstinence: A systematic review and meta-analysis	12
Concomitant use of antidepressants and classic psychedelics: A scoping review	12
Younger, drunk, and fast: Paradoxical rapid reaction time in hazardous drinkers	12
Just a gut feeling: Faecal microbiota transplant for treatment of depression – A mini-review	12
Adverse experiences resulting in emergency medical treatment seeking following the use of lysergic acid diethylamide (LSD)	12
Real-world effectiveness of repeated intravenous ketamine infusions for treatment-resistant depression in transitional age youth	12
Amphetamine use disorder is associated with striatum hypoactivation during anticipation of loss and reward	12
Temporal profile of intranasal oxytocin in the human autonomic nervous system at rest: An electrocardiography and pupillometry study	12
The association between N-methyl-d-aspartate receptor availability and glutamate levels: A multi-modal PET-MR brain imaging study in first-episode psychosis and healthy controls	12
OAV and 5D-ASC for Brazilian Portuguese: A validation and adaptation study	12
Tripping into the unknown: Exploring the experiences of first-time LSD users through global drug survey insights	11
Predicting and exploring ayahuasca effects: Perception, mind-wandering, and EEG oscillations	11
The psychedelic effects of cannabis: A review of the literature	11
No evidence that post-training dopamine D2 receptor agonism affects fear generalization in male rats	11
Sub-anesthetic doses of ketamine increase single cell entrainment in the rat auditory cortex during auditory steady-state response	11
Effects of CYP2D64* polymorphism on the steady-state concentration of paroxetine in patients diagnosed with depressive episode and comorbid alcohol use disorder	11
The psychopharmacology of mood disorders	11
Recasting the role of electroconvulsive therapy and the electroconvulsive therapy practitioner: For severe illness, not necessarily treatment-resistant depression	11
Common protein networks for various drug regimens of major depression are associated with complement and immunity	11
Causes, clinical characteristics, and outcomes of high lithium levels and intoxications: Retrospective analysis of patient records	11
Unveiling potential adverse events associated with escitalopram oxalate: A real-world analysis based FDA adverse event reporting system database	11
Intracerebroventricular knockdown of NPY1R disrupts NPY1R-GALR2/TrkB heteroreceptor complexes without affecting neuroplasticity or depressive-like behaviour	11
A randomized, double-blind, placebo-controlled, Phase 1 study to investigate the safety, tolerability, pharmacokinetics and pharmacodynamics of an immediate-release oral ketamine capsule in healthy vo	11
Pictorial representation of illness and self measure (PRISM): A putative transdiagnostic tool for evaluating therapeutic effects of psychedelic treatments	11
A transdiagnostic systematic review and meta-analysis of ketamine’s anxiolytic effects	11
Common pitfalls, and how to avoid them, in child and adolescent psychopharmacology: Part I	10
Self-treatment of psychiatric conditions using ketamine: Patterns, characteristics, and retrospective insights	10
Changes in music-evoked emotion and ventral striatal functional connectivity after psilocybin therapy for depression	10
Role of chemokines in depression: Highlights on CX ₃ CL1/CX ₃ CR1 signaling	10
Is there a risk of addiction to ketamine during the treatment of depression? A systematic review of available literature	10
The interaction between kynurenine pathway, suicidal ideation and augmentation therapy with minocycline in patients with treatment-resistant depression	10
Landscape analysis of pre-registered clinical trials involving classical psychedelics	10
Hemispheric annealing and lateralization under psychedelics (HEALS): A novel hypothesis of psychedelic action in the brain	9
Clinical correlates of early onset antipsychotic treatment resistance	9
Escitalopram should be investigated in anorexia nervosa: Rationale and review of mechanisms	9
Ketamine: A new chapter for clinical psychopharmacology?	9
Interactions of alcohol and the benzodiazepine inverse agonist in healthy male volunteers	9
Role of serotonin in modulation of decision-making in Parkinson’s disease	9
Targeting disrupted networks in schizophrenia: Can muscarinic drugs make a fundamental difference?	9
Effects of acute lysergic acid diethylamide on intermittent ethanol and sucrose drinking and intracranial self-stimulation in C57BL/6 mice	9
Trip killers: Addressing a critical knowledge gap in psychedelic research	9
Effects of clozapine treatment on the improvement of substance use disorders other than nicotine in individuals with schizophrenia spectrum disorders: A systematic review and meta-analysis	9