Psychological Medicine
January 1, 2024
Brandon Weiss, Induni Ginige, Lu Shannon et al.
38 citations
In a trial comparing psilocybin therapy with the antidepressant escitalopram for moderate-to-severe major depressive disorder, both treatments led to personality changes in a direction consistent with improved mental health. Psilocybin was linked to decreases in neuroticism, introversion, disagreeableness, and impulsivity, and increases in absorption, conscientiousness, and openness at six weeks, with some changes lasting six months. Escitalopram was linked to decreases in neuroticism, disagreeableness, and impulsivity, and increases in openness at six weeks, with neuroticism remaining decreased at six months. No significant differences between the two treatments were observed, except that patients' pre-trial positive expectations for escitalopram moderated personality changes after that treatment, but not after psilocybin.
Psychological Medicine
August 25, 2017
Philip J. Cowen
38 citations
About 15% of depressed patients who do not respond to two antidepressant trials achieve remission with subsequent therapies. For treatment-resistant depression, augmentation with atypical antipsychotics quetiapine and aripiprazole has the strongest evidence, though lithium and triiodothyronine remain useful. Ketamine shows striking antidepressant effects in resistant depression, but developing similar glutamatergic drugs for continuous use is challenging. Growing understanding of inflammation's role in depression may allow repurposing anti-inflammatory agents and stratifying patients who would benefit. The dopamine agonist pramipexole, used carefully, could improve outcomes for refractory patients.
Psychological Medicine
October 1, 2022
Ashish K Sahib, Joana R Loureiro, Megha M Vasavada et al.
36 citations
Ketamine infusion therapy can rapidly relieve depression, but its effects on whole-brain functional connections are not well understood. In patients with major depressive disorder (MDD), baseline resting-state functional connectivity (FC) differed from healthy controls in the somatomotor network and between association and default mode networks. After one and four ketamine infusions, these disrupted FC patterns trended toward those of controls. Serial ketamine treatment significantly decreased FC between the cerebellum and the salience network. Patients who remitted showed higher pre-treatment FC between the cerebellum and striatum that decreased after treatment, while non-remitters showed the opposite pattern. Ketamine induces neurofunctional plasticity in cortico-striatal-cerebellar loops involving the salience network, which may serve as a biomarker for treatment response.
Psychological Medicine
December 1, 2023
Paul McCrone, Henry Fisher, Clare Knight et al.
34 citations
Psilocybin-assisted psychotherapy (PAP) may be a cost-effective treatment for severe depression, depending on the price of the drug and the level of therapist support. A decision model compared PAP with conventional medication, cognitive behavioural therapy (CBT), and their combination over six months. PAP produced the highest quality-adjusted life years (0.310) but also the highest expected healthcare cost (£6,132 to £7,652). PAP became cost-effective when therapist support costs were reduced by 50% and the psilocybin price dropped to £400–£800 per person. From a societal perspective, PAP's cost-effectiveness improved further. More long-term outcome data are needed.
Psychological Medicine
February 1, 1977
R. Rodnight, R. M. Murray, M. C. H. Oon et al.
33 citations
Dimethyltryptamine (DMT) was detected in the urine of 47% of patients diagnosed with schizophrenia, 38% of those with other non-affective psychoses, 13% of those with affective psychoses, 19% of those with neurotic and personality disorders, and 5% of normal subjects. Operational definitions of psychosis did not identify any group more strongly associated with urinary DMT than a hospital diagnosis of schizophrenia. A discriminant function analysis of symptoms identified a group of 21 patients, of whom 71% excreted detectable DMT. A general relationship between psychotic symptoms and urinary DMT existed, but specifically schizophrenic symptoms were not major determinants of DMT excretion.
Psychological Medicine
April 28, 2020
Claire Mokrysz, Natacha D. C. Shaban, Tom P. Freeman et al.
24 citations
Inhaling cannabis reliably increases psychotic-like symptoms in healthy cannabis users and may raise the incidence of speech illusion—hearing words in meaningless white noise. Cannabidiol (CBD) did not blunt these effects. In one study, adults had stronger psychotic-like symptom responses than adolescents, suggesting adolescents may be less vulnerable to the acute psychotic-like effects of cannabis. The odds of experiencing speech illusion were 3.1 times higher after inhaling cannabis with THC and negligible CBD compared to placebo.
Psychological Medicine
November 1, 2012
E. M. Marks, C. Steel, E. R. Peters
20 citations
People who report unusual perceptual or belief experiences (anomalous experiences) but do not need clinical care are more prone to intrusive memories after watching a traumatic film than people with few such experiences. These intrusive memories are more vivid, emotional, and involuntary—resembling those seen in PTSD. The findings support the idea that a weak tendency to integrate information into its broader context may make some individuals vulnerable to intrusions, a symptom common to both PTSD and schizophrenia. A concurrent visuospatial task did not reduce intrusions in either group.
Psychological Medicine
November 20, 2024
B Yildirim, S S Sahin, A Gee et al.
19 citations
Psychedelic drugs are being studied for treating depression, but concerns about psychiatric side effects persist. A review of case reports found 17 cases of schizophrenia spectrum disorder and 17 of affective disorder (depression, mania, or both) after psychedelic use, excluding people with prior psychiatric illness or other drug use. These conditions could begin after a single use (5 of 17 schizophrenia cases; 6 of 17 affective disorder cases). Recovery was typical for affective disorder but not for schizophrenia spectrum disorder. Among 29 flashback cases, 12 had lasting psychiatric symptoms, mainly anxiety (5 cases) and depression (8 cases). Flashbacks resolved within a year in about half of cases but persisted for years in a few. Serious psychiatric disorders after psychedelic use are uncommon but documented.
Psychological Medicine
June 1, 2023
Ben Alderson-Day, Peter Moseley, Kaja Mitrenga et al.
19 citations
Felt presence—the sense that someone else is nearby when no one is there—occurs across neurology, bereavement, psychosis, hypnagogic states, solo sports, and spiritual experiences, but systematic comparisons are rare. Three online surveys compared felt presence in people with psychosis or voice-hearing (75 participants), spiritualist believers (47 participants), and endurance/solo athletes (84 participants). Hierarchical linear regression showed that a general tendency toward hallucinations predicted felt presence frequency in all groups; paranoia and female gender were additional predictors in the psychosis sample. Qualitative analysis revealed shared features, especially immersive states, across contexts. The findings support a unitary model of felt presence, suggesting common underlying mechanisms.
Psychological Medicine
December 7, 2020
Nicholas T. van Dam, Julieta Galante
19 citations
A critique of a recent study on harm after mindfulness-based stress reduction (MBSR) programs points out serious methodological limitations that undermine confidence in the authors' conclusion that MBSR is no more harmful than no treatment. The original study used a large observational dataset of 2,155 participants alongside active and wait-list arms of randomized controlled trials (156 and 118 participants respectively). The critique argues that despite the seemingly conclusive finding, the methods employed have potentially serious flaws.
Psychological Medicine
October 1, 2022
Wayne Hall, Keith Humphreys
18 citations
No Summary
Psychological Medicine
September 1, 2022
Benjamin Wade, Joana R Loureiro, Ashish K Sahib et al.
18 citations
Before serial ketamine infusion, brain structure, function, and connectivity measures predicted how much depressive symptoms changed afterward. In 60 patients with depression, machine learning models using pretreatment MRI scans explained 19% of variance in core mood and anhedonia symptoms, 27% in a depression subscale, and 1% in rumination reflection. Greater connectivity in the right medial prefrontal cortex, anterior cingulate, and posterior insula, along with lower kurtosis of a white-matter tract, predicted larger symptom reductions. Connectivity of the left posterior cingulate, left insula, and right superior parietal lobule predicted changes in rumination. These findings suggest that anterior default mode network and posterior insula connectivity may serve as biomarkers for antidepressant response.
Psychological Medicine
April 1, 2024
Otto Simonsson, Walter Osika, Cecilia U.D. Stenfors et al.
15 citations
People who used psychedelics during a two-month period reported a greater increase in days of mindfulness meditation per week than those who did not. Among psychedelic users, experiencing personal insight during the most intense psychedelic session was linked to larger increases in both mindfulness and loving-kindness or compassion meditation practice. Conversely, more frequent loving-kindness or compassion meditation at the start of the study was associated with less severe feelings of death or dying during the subsequent psychedelic experience. These findings suggest a bidirectional relationship: psychedelics may boost meditation engagement, while meditation may reduce challenging psychedelic experiences.
Psychological Medicine
May 27, 2019
Oyedeji Ayonrinde
11 citations
A historiographic review of the 1892 Indian Hemp Drugs Commission report shows that heavy cannabis use was linked to severe mental illness, accounting for 7.3% of asylum patients and 12.6% of those with diagnoses. About two-thirds were children and young adults, with higher relapse rates. Risk increased with early cannabis use and family history of mental illness. Cannabis psychosis had a shorter trajectory and better prognosis than other mental illnesses. Different cannabis potency and consumption methods had varying effects, while occasional use was considered medicinally beneficial. The report's observations on dose-related effects and psychosis risk in vulnerable young people align with current knowledge.
Psychological Medicine
January 1, 2025
Chiara Caporuscio, Christopher Poppe, Astrid Gieselmann et al.
9 citations
A scoping review of ethical issues in psychedelic-assisted therapy identifies seven key themes: safety and patient well-being, therapeutic relationships, informed consent, equity and access, research ethics, special contexts, and societal and cultural implications. The review systematically searched multiple databases for peer-reviewed studies on human participants and psychiatric patients, covering publications up to June 2025. The findings aim to inform further discussion and research to support safer and more ethical implementation of psychedelic-assisted treatments as they approach clinical use.
Psychological Medicine
February 1, 2024
Pavo Orepic, Fosco Bernasconi, Melissa Faggella et al.
9 citations
A robotic procedure that creates sensorimotor conflicts and a feeling of another person's presence can induce auditory-verbal hallucination (AVH)-like sensations in healthy individuals. In two studies, participants showed increased false alarm rates on a voice detection task. Stronger sensorimotor conflicts led to more AVH-like sensations, supporting the self-monitoring deficit account. The otherness condition produced more false alarms when detecting other-voice stimuli than self-voice stimuli, consistent with the strong perceptual priors account. The findings integrate both theoretical models of AVH.
Psychological Medicine
October 1, 2023
Imke Hanssen, Marloes J. Huijbers, Eline Regeer et al.
7 citations
Adding mindfulness-based cognitive therapy (MBCT) to treatment as usual (TAU) for bipolar disorder did not reduce depressive symptoms more than TAU alone at post-treatment or at 15 months follow-up. The 144 participants with bipolar I or II were randomly assigned to MBCT plus TAU or TAU only. At post-treatment, MBCT improved mindfulness skills more than TAU. At follow-up, TAU was more effective than MBCT plus TAU for reducing trait anxiety and improving mindfulness skills and positive mental health. Participants with higher baseline depression and functional impairment benefited more from MBCT plus TAU, suggesting MBCT may help those with moderate to severe depression and impairment.
Psychological Medicine
August 8, 2025
Giulia Trotta, Edoardo Spinazzola, Hannah Degen et al.
4 citations
Childhood trauma, especially emotional and physical abuse, is strongly linked to paranoia, and cannabis use amplifies that effect. In a survey of 4,736 adults, those who experienced childhood trauma reported higher paranoia, and weekly cannabis use—measured in standard THC units—also predicted greater paranoia. Cannabis use partially mediated the link between trauma and paranoia, though trauma itself had a much larger direct effect. The findings suggest that assessing both trauma history and cannabis exposure in standard THC units could improve risk detection and guide interventions for people with childhood trauma.
Psychological Medicine
August 26, 2025
Lydia Johnson-Ferguson, Michelle Loher, Laura Bechtiger et al.
2 citations
Frequent cannabis use in young adulthood predicts increases in psychotic-like experiences, internalizing symptoms, aggression, problematic substance use, and higher odds of not being in employment, education, or training, along with decreased general well-being from ages 20 to 24. These associations held whether cannabis exposure was measured by self-reported frequency or by hair THC concentrations, and effect sizes were small. Composite measures combining self-reports and hair data were no more informative than either source alone. The findings come from a community sample of 863 young adults, with 150 reporting weekly-to-daily use and 110 having detectable cannabis in hair at age 20.
Psychological Medicine
July 19, 2023
Brandon Weiss, Induni Ginige, Lu Shannon et al.
1 citation
No Summary
Psychological Medicine
May 8, 2026
Lou-Anne Chavigny, Véronique Desbeaumes Jodoin, Nicolas Garel et al.
A systematic review of 21 studies involving approximately 900–1,180 participants with treatment-resistant depression found that low-dose intravenous ketamine preserves and enhances certain cognitive functions. Improvements were frequently observed in processing speed and working memory, while attention remained stable or modestly improved. Results for verbal and visual memory varied across studies. Executive control, especially inhibitory performance on Stroop tasks, improved in several trials. No cognitive worsening was reported. Two studies directly examined cognition in relation to suicidal behaviors, suggesting that procognitive effects, particularly in executive control, may mediate ketamine's antisuicidal action. Standardized longitudinal studies are needed to clarify durability and clinical significance.
Psychological Medicine
February 4, 2026
Katrina Mysko, Elise Quarterman Gear, Lyn Ellett
A systematic review and meta-analysis found a small negative association between trait mindfulness and psychotic-like experiences (PLEs) in nonclinical populations, meaning higher mindfulness levels are linked to fewer PLEs. However, mindfulness-based interventions showed no significant effect on reducing PLEs in these populations. The pooled correlation from eight studies was -0.25, and the summary effect from five intervention studies was not significant. The findings should be interpreted cautiously due to the small number of studies and high heterogeneity.
Psychological Medicine
January 12, 2026
Lawrence Kin-Hei Chung, Thomas J Whitford, Anson Kai Chun Chau et al.
People with schizophrenia who hear voices experience inner speech—the silent, internal monologue—more frequently and with a different character than healthy individuals. Using repeated daily surveys on electronic devices, researchers found that voice-hearers reported more moments of inner speech and higher intensity of evaluative, other people's voices, condensed, and positive inner speech, though not dialogic inner speech. When voice-hearers experienced more intense dialogic, evaluative, other people's, or condensed inner speech, they also reported more severe auditory verbal hallucinations. Negative emotions strengthened the link between evaluative inner speech and hallucination severity. The findings suggest inner speech contributes to voice-hearing and that emotional state may be a target for therapy.
Psychological Medicine
January 1, 2026
Ricarda Evens, Abdo Uyar, Emily Gosslau et al.
About 31% of people who had a distressing psychedelic experience that lasted beyond the acute phase met diagnostic criteria for post-traumatic stress disorder (PTSD). Avoidance during the acute experience predicted worse PTSD symptoms, while acceptance predicted milder symptoms. Post-traumatic growth was unrelated to the intensity of the challenge or avoidance but was linked to acceptance. Most participants sought help from online resources or friends, though psychotherapy was rated most helpful. The study targeted those with highly challenging experiences, so findings do not reflect prevalence among all psychedelic users.
Psychological Medicine
January 1, 2025
Sunjeev K. Kamboj, Matthew Peniket, Jessica Norman et al.
Transcutaneous vagus nerve stimulation (tVNS) combined with a brief self-compassion mental imagery training (SC-MIT) produced a larger acute increase in state self-compassion and mindfulness than either intervention alone in healthy adults. Over eight daily sessions, tVNS plus SC-MIT showed accumulating effects on mindfulness but not self-compassion. Self-criticism and attentional bias toward compassionate faces were influenced only by the type of imagery training, not by stimulation. Heart rate variability was unaffected by any condition. The findings suggest tVNS may enhance meditation-based psychotherapies, while oculomotor metrics appear sensitive to self-compassion training.