OOIR: Observatory of International Research

Papers

(The TQCC of Journal of Psychopharmacology is 10. 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 2021-11-01 to 2025-11-01.)

Article	Citations
Cannabimimetic and discriminative stimulus effects of hexahydrocannabinols in mice	302
Effects of initial nicotine exposure on cognition and nicotine reinforcement among non-smoking young adults with and without attention deficit hyperactivity disorder	224
Effectiveness of vortioxetine in elderly patients with major depressive disorder in real-world clinical practice: Results from the RELIEVE study	140
Circadian rhythmicity in prepulse inhibition of the acoustic startle response: A study of chronotype and time-of-day effects in young healthy adults	121
Glutamate levels across deep brain structures in patients with a psychotic disorder and its relation to cognitive functioning	94
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	83
Perceptions of safety, subjective effects, and beliefs about the clinical utility of lysergic acid diethylamide in healthy participants within a novel intervention paradigm: Qualitative results from a	79
Science, safety and education: Informing the psychedelic treatment of psychiatric disorders	69
Interactions between classic psychedelics and serotonergic antidepressants: Effects on the acute psychedelic subjective experience, well-being and depressive symptoms from a prospective survey study	63
Deaths related to the use of diarylethylamines, with a focus on the United Kingdom: A systematic review and case series report	57
Off the RADAR; questions regarding the trial protocol of a randomised controlled trial of antipsychotic reduction and discontinuation	56
The revival of the psychedelic experience scale: Revealing its extended-mystical, visual, and distressing experiential spectrum with LSD and psilocybin studies	47
Proportion of Antipsychotics with CYP2D6 Pharmacogenetic (PGx) Associations Prescribed in an Early Intervention in Psychosis (EIP) Cohort: A Cross-Sectional Study	45
Co-use of psychedelics with other substances: Findings from the global psychedelic survey	45
Psychedelics and the ‘inner healer’: Myth or mechanism?	45
Meditating on psychedelics. A randomized placebo-controlled study of DMT and harmine in a mindfulness retreat	44
Repurposing psychopharmacology: A two-way street?	43
Relationship between change in social evaluation learning and mood in early antidepressant treatment: A prospective cohort study in primary care	42
A reflection on paradigmatic tensions within the FDA advisory committee for MDMA-assisted therapy	41
Solriamfetol improves daily fatigue symptoms in adults with myalgic encephalomyelitis/chronic fatigue syndrome after 8 weeks of treatment	39
A framework for assessment of adverse events occurring in psychedelic-assisted therapies	38
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	38
Cannabidiol in clinical and preclinical anxiety research. A systematic review into concentration–effect relations using the IB-de-risk tool	38
Pharmaco-fUS in cognitive impairment: Lessons from a preclinical model	37
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	37

Associations between regular cannabis use and brain resting-state functional connectivity in adolescents and adults	36
The effects of antenatal depression and SSRI exposure on children: A systematic review	36
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	34
Elevated C-reactive protein among symptomatic youth with bipolar disorder	34
What are set and setting: Reducing vagueness to improve research and clinical practice	33
The New Zealand drug harms ranking study: A multi-criteria decision analysis	32
Serotonin release by parachloroamphetamine in rats with high and low sociability: High prefrontal release capacity in sociable females	32
The empathogen 3,4-methylenedioxymethamphetamine, but not methamphetamine, increases feelings of global trust	32
Ketamine use in a large global sample: Characteristics, patterns of use and emergency medical treatment	31
Voluntary nicotine consumption and reward in a subset of diversity outbred founder strains	30
Haloperidol dopamine receptor occupancy and antagonism correspond to delirium agitation scores and EPS risk: A PBPK-PD modeling analysis	30
Corrigendum: Is psychedelic use associated with cancer? Interrogating a half-century-old claim using contemporary population-level data	29
Mind the gap! Addressing unresolved aspects of abuse potential evaluation and scheduling of classic and novel psychedelic drugs	29
A phase 1b study to investigate the potential interactions between ASP8062 and buprenorphine/naloxone in patients with opioid use disorder	28
Postpartum depression: A role for psychedelics?	28
Not too quick on “Debunking the myth of ‘Blue Mondays’”	28
Wistar Kyoto rats exhibit decreased serotonin neuronal firing and increased norepinephrine burst activity but dampened hippocampal α₂-adrenoceptor sensitivity	27
Oral esketamine for patients with severe treatment-resistant depression: Effectiveness, safety, and tolerability of a six-week open-label treatment program	26
Drug–drug interactions involving classic psychedelics: A systematic review	25
The low risk for early renal damage during lithium treatment has not changed over time	25
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)	24
Impact of psychedelics on craving in addiction: A systematic review	24
Psychedelic-assisted psychotherapy: The need to monitor adverse events	24
Altered amygdala-cortical connectivity in individuals with Cannabis use disorder	23
Associations of antidepressants and antipsychotics with lipid parameters: Do CYP2C19/CYP2D6 genes play a role? A UK population-based study	23
The mechanism of action of clozapine	22
Hippocampal phase precession is preserved under ketamine, but the range of precession across a theta cycle is reduced	22
Effect of alcohol coadministration on the pharmacodynamics, pharmacokinetics, and safety of lemborexant: A randomized, placebo-controlled crossover study	22
Associations between paraoxonase-1 activity and therapeutic drug monitoring indicators in schizophrenia patients treated with olanzapine: A cross-sectional study	21
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	21
Effect of CannEpil^® on simulated driving performance and co-monitoring of ocular activity: A randomised controlled trial	21
Evaluation of the sedative-motor effects of novel GABAkine imidazodiazepines using quantitative observation techniques in rhesus monkeys	21
Psilocybin for clinical indications: A scoping review	21
Associations between MDMA/ecstasy use and physical health in a U.S. population-based survey sample	21
A critical evaluation of QIDS-SR-16 using data from a trial of psilocybin therapy versus escitalopram treatment for depression	21
Impact of drug-induced Parkinsonism and tardive dyskinesia on health-related quality of life in schizophrenia	21
Examining mystical experiences as a predictor of psilocybin-assisted psychotherapy for treatment-resistant depression	20
Eight-week antidepressant treatment effects on connectome gradient in first-episode drug-naïve patients with major depressive disorder	19
Can psychedelics enhance group psychotherapy? A discussion on the therapeutic factors	19
Evidence-based guidelines for the interpretation of the 9-item Concise Health Risk Tracking – Self-Report (CHRT-SR₉) measure of suicidal risk	19
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	19
The antidepressant effect and safety of non-intranasal esketamine: A systematic review	19
Is lack of goal-conflict-specific rhythmicity a biomarker for treatment resistance in generalised anxiety but not social anxiety or major depression?	18
Comparative safety of chronic versus intermittent benzodiazepine prescribing in older adults: A population-based cohort study	18
The effects of reserpine on depression: A systematic review	18
Chronic Cannabis users exhibit altered oscillatory dynamics and functional connectivity serving visuospatial processing	18
Modafinil: A closer look at its theoretical toxicological potential	18
Examining the role of systemic chronic inflammation in diet and sleep relationship	18
A three-stage strategy for conducting an experimental investigation: A recommendation to improve the reproducibility of reported conclusions	17
Older adults in psychedelic-assisted therapy trials: A systematic review	17

Is microdosing a placebo? A rapid review of low-dose LSD and psilocybin research	17
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	17
Mechanisms of psilocybin on the treatment of posttraumatic stress disorder	17
Pivotal role of orexin signaling in the posterior paraventricular nucleus of the thalamus during the stress-induced reinstatement of oxycodone-seeking behavior	17
Blackcurrant ( Ribes nigrum L.) improves cholinergic signaling and protects against chronic Scopolamine-induced memory impairment in mice	16
Escitalopram and functional connectivity in major depressive disorder: A systematic review	16
Differences in social brain function in autism spectrum disorder are linked to the serotonin transporter: A randomised placebo-controlled single-dose crossover trial	16
The effects of selective serotonin reuptake inhibitors on memory functioning in older adults: A systematic literature review	16
A letter to the editor, associated with the article entitled “Efficacy and tolerability of combination treatments for major depression: Antidepressants plus second-generation antipsychotics vs esketam	15
Efficacy and safety of supraphysiologic doses of levothyroxine for patients with bipolar depression in adults: A systematic review	15
Revisiting monoamine oxidase inhibitors: A potential dual-action therapy for patients with prostate cancer and comorbid depression?	15
Amphetamine use disorder is associated with striatum hypoactivation during anticipation of loss and reward	15
Episodic foresight is impaired following acute alcohol intoxication	15
Subjectively reported sleep improvement with antipsychotic medications in clinical practice: A systematic review, meta-analysis and meta-regression of moderating factors	14
Just a gut feeling: Faecal microbiota transplant for treatment of depression – A mini-review	14
Common protein networks for various drug regimens of major depression are associated with complement and immunity	14
Adverse experiences resulting in emergency medical treatment seeking following the use of lysergic acid diethylamide (LSD)	14
Psilocybin microdosing does not affect emotion-related symptoms and processing: A preregistered field and lab-based study	14
Efficacy and safety of psilocybin-assisted treatment for major depressive disorder: Prospective 12-month follow-up	14
We need to talk: The urgent conversation on chronic pain, mental health, prescribing patterns and the opioid crisis	14
The CannTeen Study: Cannabis use disorder, depression, anxiety, and psychotic-like symptoms in adolescent and adult cannabis users and age-matched controls	14
Significance of mammalian N, N-dimethyltryptamine (DMT): A 60-year-old debate	14
Temporal profile of intranasal oxytocin in the human autonomic nervous system at rest: An electrocardiography and pupillometry study	14
Pictorial representation of illness and self measure (PRISM): A putative transdiagnostic tool for evaluating therapeutic effects of psychedelic treatments	13
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	13
Younger, drunk, and fast: Paradoxical rapid reaction time in hazardous drinkers	13
The psychedelic effects of cannabis: A review of the literature	13
OAV and 5D-ASC for Brazilian Portuguese: A validation and adaptation study	13
Recasting the role of electroconvulsive therapy and the electroconvulsive therapy practitioner: For severe illness, not necessarily treatment-resistant depression	13
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	13
Real-world effectiveness of repeated intravenous ketamine infusions for treatment-resistant depression in transitional age youth	13
Unveiling potential adverse events associated with escitalopram oxalate: A real-world analysis based FDA adverse event reporting system database	12
Is there a risk of addiction to ketamine during the treatment of depression? A systematic review of available literature	12
Concomitant use of antidepressants and classic psychedelics: A scoping review	12
The psychopharmacology of mood disorders	12
Effects of CYP2D64* polymorphism on the steady-state concentration of paroxetine in patients diagnosed with depressive episode and comorbid alcohol use disorder	12
Causes, clinical characteristics, and outcomes of high lithium levels and intoxications: Retrospective analysis of patient records	12
The interaction between kynurenine pathway, suicidal ideation and augmentation therapy with minocycline in patients with treatment-resistant depression	12
Adverse effects of psychedelics: From anecdotes and misinformation to systematic science	11
Role of serotonin in modulation of decision-making in Parkinson’s disease	11
Clinical correlates of early onset antipsychotic treatment resistance	11
Tripping into the unknown: Exploring the experiences of first-time LSD users through global drug survey insights	11
Self-treatment of psychiatric conditions using ketamine: Patterns, characteristics, and retrospective insights	11
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	11
Interactions of alcohol and the benzodiazepine inverse agonist in healthy male volunteers	11
Hippocampal and parahippocampal volume and function predict antidepressant response in patients with major depression: A multimodal neuroimaging study	11
No evidence that post-training dopamine D2 receptor agonism affects fear generalization in male rats	11
A transdiagnostic systematic review and meta-analysis of ketamine’s anxiolytic effects	11
Sub-anesthetic doses of ketamine increase single cell entrainment in the rat auditory cortex during auditory steady-state response	11
Ketamine: A new chapter for clinical psychopharmacology?	11
Mapping acute alcohol effects on bodily sensations: A cross-dimensional interoceptive approach	11
Effects of acute lysergic acid diethylamide on intermittent ethanol and sucrose drinking and intracranial self-stimulation in C57BL/6 mice	11
Changes in music-evoked emotion and ventral striatal functional connectivity after psilocybin therapy for depression	11
Landscape analysis of pre-registered clinical trials involving classical psychedelics	11
Common pitfalls, and how to avoid them, in child and adolescent psychopharmacology: Part I	11
Effect of selective serotonin reuptake inhibitor discontinuation on anxiety-like behaviours in mice	11
Escitalopram should be investigated in anorexia nervosa: Rationale and review of mechanisms	10
Targeting disrupted networks in schizophrenia: Can muscarinic drugs make a fundamental difference?	10
Naturalistic use of psychedelics is related to emotional reactivity and self-consciousness: The mediating role of ego-dissolution and mystical experiences	10
Hemispheric annealing and lateralization under psychedelics (HEALS): A novel hypothesis of psychedelic action in the brain	10
Investigation of self-treatment with lysergic acid diethylamide and psilocybin mushrooms: Findings from the Global Drug Survey 2020	10
Increasing recreational nitrous oxide use: Should we worry? A narrative review	10