Cannabis use often begins in adolescence and young adulthood, when anxiety, depression, psychosis, and bipolar disorder typically first develop. Young people aged in their mid-teens to mid-twenties who engage in daily cannabis use and develop a cannabis use disorder have a higher prevalence of these mental disorders. We assessed the coherence of evidence from epidemiological, genetic,...
Placebo effects are among the greatest paradoxes in medical research. Although more data on placebos are available from placebo-controlled trials than on any treatment in medicine, there has been comparatively little deep interrogation of issues related to their measurement, appraisal, and interpretation. Most of the work that has been done, including that in psychiatry, is narrowly focused on...
In the past three decades, psychiatric research has increasingly focused on the early subthreshold stages of psychosis, with the aim of improving the early identification and treatment of individuals at increased risk of psychotic disorder. Yet, despite considerable research effort, current early psychosis research faces several limitations. In this Personal View, we consider how integrating...
Delusions in psychosis involve complex and dynamic experiential, affective, cognitive, behavioural, and interpersonal alterations. Their pattern of emergence during the early stages of illness remains poorly understood and the origin of their thematic content unclear. Phenomenological accounts have emphasised alterations of selfhood and reality experience in delusion formation but have not...
Non-remission after psychological therapy for major depressive disorder is common, yet there are no established further-line treatments. In the UK National Health Service (NHS) Talking Therapies programme, about 50% of patients with depression who come to the end of the stepped care pathway do not show remission of symptoms. We aimed to investigate whether mindfulness-based cognitive therapy...
Although studies of psychedelic-assisted psychotherapy are accumulating, there is no consensus regarding best practice of the psychotherapeutic component. In this systematic review, we summarised the quality of reporting on psychological interventions in research about psychedelic treatments. The design followed PRISMA guidelines and was preregistered in PROSPERO (CRD42022319221). We searched...
Attempts to understand psychosis-the experience of profoundly altered perceptions and beliefs-raise questions about how the brain models the world. Standard predictive coding approaches suggest that it does so by minimising mismatches between incoming sensory evidence and predictions. By adjusting predictions, we converge iteratively on a best guess of the nature of the reality. Recent...
Treatment of psychiatric disorders with psychedelic substances represents one of the most promising current treatment approaches in psychiatry. Since its inception in the 1950s, therapy with psychedelics has been conceptualised as psychedelic-assisted psychotherapy-ie, a form of psychotherapy that uses the profound biological effects of this class of substances as a catalyst for changing...
Ketamine is an effective antidepressant, but there is substantial variability in patient response and the precise mechanism of action is unclear. Neuroimaging can provide predictive and mechanistic insights, but findings are limited by small sample sizes. This systematic review covers neuroimaging studies investigating baseline (pre-treatment) and longitudinal (post-treatment) biomarkers of...
The felt presence experience is the basic feeling that someone else is present in the immediate environment, without clear sensory evidence. Ranging from benevolent to distressing, personified to ambiguous, felt presence has been observed in neurological case studies and within psychosis and paranoia, associated with sleep paralysis and anxiety, and recorded within endurance sports and...
Ketamine has rapid yet often transient antidepressant effects in patients with treatment-resistant depression. Different strategies have been proposed to prolong these effects. Maintenance ketamine treatment appears promising, but little is known about its efficacy, safety, and tolerability in depression. We searched Pubmed, Embase, and the Cochrane Library and identified three randomised...
Cannabis potency, defined as the concentration of Δ9-tetrahydrocannabinol (THC), has increased internationally, which could increase the risk of adverse health outcomes for cannabis users. We present, to our knowledge, the first systematic review of the association of cannabis potency with mental health and addiction (PROSPERO, CRD42021226447). We searched Embase, PsycINFO, and MEDLINE (from...
There have been renewed calls to use phenomenology in psychiatry to improve knowledge about causation, diagnostics, and treatment of mental health conditions. A phenomenological approach aims to elucidate the subjective experiences of mental health, which its advocates claim have been largely neglected by current diagnostic frameworks in psychiatry (eg, DSM-5). The consequence of neglecting...
BACKGROUND Delusions are a common transdiagnostic feature of psychotic disorders, and their treatment remains suboptimal. Despite the pressing need to better understand the nature, meaning, and course of these symptoms, research into the lived experience of delusional phenomena in psychosis is scarce. Thus, we aimed to explore the lived experience and subjective apprehension of delusions in...
Background: Medicinal cannabinoids, including medicinal cannabis, pharmaceutical cannabinoids and their synthetic derivatives, including tetrahydrocannabinol (THC) and or cannabidiol (CBD), have been suggested to have a therapeutic role for certain mental health conditions. The primary objective was to review the evidence for cannabinoids in treating symptoms of depression, anxiety,...
Summary Background Cannabis use is associated with increased risk of later psychotic disorder but whether it affects incidence of the disorder remains unclear. We aimed to identify patterns of cannabis use with the strongest effect on odds of psychotic disorder across Europe and explore whether differences in such patterns contribute to variations in the incidence rates of psychotic disorder....
Post-traumatic stress disorder (PTSD) is a complex and difficult-to-treat disorder, affecting 10-20% of military veterans. Previous research has raised the question of whether a non-trauma-focused treatment can be as effective as trauma exposure therapy in reducing PTSD symptoms. This study aimed to compare the non-trauma-focused practice of Transcendental Meditation (TM) with prolonged...
Published online at: https://doi.org/10.1016/S2215-0366(18)30170-6 Eligible users can access the full text via NHS OpenAthens at [https://www.clinicalkey.com/#!/content/journal/1-s2.0-S2215036618301706] (login required).
Background: Post-traumatic stress disorder (PTSD) is prevalent in military personnel and first responders, many of whom do not respond to currently available treatments. This study aimed to assess the efficacy and safety of 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy for treating chronic PTSD in this population. Methods: We did a randomised, double-blind, dose-response,...
This is the first systematic review of the safety of ketamine in the treatment of depression after single and repeated doses. We searched MEDLINE, PubMed, PsycINFO, and Cochrane Databases and identified 288 articles, 60 of which met the inclusion criteria. After acute dosing, psychiatric, psychotomimetic, cardiovascular, neurological, and other side-effects were more frequently reported after...
Cannabis use and related problems are on the rise globally alongside an increase in the potency of cannabis sold on both black and legal markets. Additionally, there has been a shift towards abandoning prohibition for a less punitive and more permissive legal stance on cannabis, such as decriminalisation and legalisation. It is therefore crucial that we explore new and innovative ways to reduce...
Background Cannabis use following the onset of first-episode psychosis has been linked to both increased risk of relapse and non-adherence with antipsychotic medication. Whether poor outcome associated with cannabis use is mediated through an adverse effect of cannabis on medication adherence is unclear. Methods In a prospective analysis of data acquired from four different adult inpatient and...
Summary Background The use of electroconvulsive therapy (ECT) is limited by concerns about its cognitive adverse effects. Preliminary evidence suggests that administering the glutamate antagonist ketamine with ECT might alleviate cognitive adverse effects and accelerate symptomatic improvement; we tested this in a randomised trial of low-dose ketamine. Methods In this multicentre, randomised,...
We present a review and analysis of the ethical considerations in off-label ketamine use for severe, treatment-resistant depression. The analysis of ethical considerations is contextualised in an overview of the evidence for ketamine use in depression, and a review of the drug's safety profile. We find that, based on current evidence, ketamine use for severe, treatment-resistant depression does...
BACKGROUND Although cannabis use after a first episode of psychosis has been associated with relapse, little is known about the determinants of this most preventable risk factor for relapse of psychosis. Here we aimed to study whether the effects on outcome vary depending on the type of cannabis consumed and usage pattern. METHODS In this observational study, we prospectively recruited and...