Cannabis is the most widely used psychoactive substance subject to legal restriction worldwide, and one of its best-characterized acute effects is a distortion of the lived sense of time: users reliably report that time slows, fragments, or loses its ordinary continuity, an effect documented since the earliest controlled studies of marijuana intoxication and confirmed across decades of...
Intranasal esketamine has been available for treatment-resistant depression (TRD) since 2019, but the trials that led to its approval answer only some of the questions prescribers face. About 97% of trial participants had failed only one or two antidepressant classes, and patients with bipolar disorder, psychosis, obsessive–compulsive disorder, four personality disorders, moderate-to-severe...
Psychiatry InternationalSeptember 10, 2026Tommaso Barlattani, Giorgio Sernia, Chiara D’Amelio et al.
Background: Evidence for repeated intranasal esketamine in obsessive–compulsive disorder (OCD) remains preliminary, particularly when OCD co-occurs with treatment-resistant depression (TRD). Methods: We report a 58-year-old woman treated with intranasal esketamine in routine clinical care for TRD; change in obsessive–compulsive symptoms was followed as a secondary observational outcome. Her...
BACKGROUND Cannabis-induced psychosis presents complex sex-based disparities that challenge traditional epidemiological patterns. While males demonstrate higher cannabis use rates, emerging evidence reveals paradoxical vulnerability patterns where females may show heightened susceptibility to cannabis-related psychotic outcomes despite lower consumption rates. OBJECTIVE To map evidence for...
Functional recovery in cannabis-induced first-episode psychosis (FEP) remains incompletely understood. Dissociative symptoms, frequently associated with cannabis use, may represent a key but underexplored determinant of functional trajectories. This prospective cohort study followed 72 patients meeting DSM-5 criteria for cannabis-induced psychotic disorder over 24 months. Functional recovery...
Background and hypothesis Cannabis use initiation during adolescence has increased globally, raising concerns about neurodevelopmental consequences during this critical period when the brain undergoes extensive remodeling in cannabinoid receptor-rich regions. Study design This systematic review examines neurodevelopmental consequences of adolescent cannabis use, focusing on structural brain...
Distinguishing substance-induced psychotic disorders (SIPD) from primary psychotic disorders with concurrent substance use remains a critical diagnostic challenge for treatment planning and prognostic counseling. To systematically review the clinical phenomenology of SIPD, identify distinguishing symptom patterns, and examine relationships between phenomenology and outcomes. A systematic search...
BACKGROUND Cannabis-induced psychotic disorders represent 12-35% of first-episode psychosis presentations globally. Traditional clinical wisdom holds these conditions carry favorable prognosis based on rapid symptomatic improvement, yet this narrative rests almost exclusively on symptomatic outcomes, overlooking functional, cognitive, and subjective recovery dimensions. OBJECTIVE To...
BACKGROUND Novel psychoactive substances (NPS) represent an evolving public health threat, yet evidence on their acute and long-term psychiatric consequences remains limited. OBJECTIVE To systematically review psychiatric and neurological consequences of NPS use across the full clinical spectrum, with primary focus on synthetic cannabinoids and related compounds, and to characterize...
Healthcare professionals encounter challenges in discerning endogenous and exogenous, drug-related, psychopathological phenomena. This study aimed to explore qualitative differences between hallucinations in schizophrenia and two forms of substance-related psychosis. These are substance-induced psychosis (SIP), which has an acute onset and is usually transient, and substance-related persistent...
Objective: To scope the available literature on antipsychotic treatment in substance-induced psychotic disorders, summarize evidence across substance categories, and highlight priorities for future research. Methods: This scoping review followed Arksey and O’Malley’s framework and PRISMA-ScR guidelines. A systematic search of PubMed, Scopus, Embase, PsycINFO, and Cochrane Library (January...
AbstractBackground and ObjectivesCannabis use is associated with psychotic disorder onset and exacerbation. This study examines how continued cannabis use affects depressive symptoms, psychotic symptoms, and suicidal behaviors following cannabis‐induced first‐episode psychosis (FEP).MethodsSixty‐five participants (aged 16–50 years) with FEP were recruited from psychiatric inpatient facilities...
Cannabis-induced psychosis (CIP) represents a significant public health concern in the context of increasing global cannabis use and potency. This review synthesizes current evidence on the epidemiology, neurobiological mechanisms, clinical features, and treatment approaches for cannabis-induced psychotic disorders. Recent epidemiological data indicate rising incidence rates of CIP, with...
Cannabis use represents a significant risk factor for both psychotic disorders and suicidal behaviors, with growing evidence suggesting complex interactions between these variables. This systematic review examines the relationship between cannabis use and suicide risk in first-episode psychosis (FEP) patients, and explores underlying mechanisms, moderating factors, and intervention strategies....
AIMS: This study aimed to investigate the differences in psychotic symptomatology, dissociative symptoms, alexithymia, and aberrant salience among three groups: non-cannabis users (NU), natural cannabis users (NC), and synthetic cannabinoid users (SCs). The study also explored the patterns of alexithymia and its associations with other psychopathological dimensions in these populations....
The phenomenology of depression is characterized by a wide array of emotional, cognitive, and physical symptoms that significantly disrupt an individual's life. Societal changes, driven by technological advancements, economic pressures, environmental concerns including climate change, and shifting cultural norms, have influenced how depression manifests and is understood. These developments...
Epidemiological data have provided evidence that psychotic-like experiences (PLEs) occur in the general population without clinical impairment. According to the psychosis continuum hypothesis, PLEs are subject to multiple risk factors. This review synthesizes current research on biological, substance use-related, and environmental risk factors for PLEs in non-clinical populations....
The increasing prevalence of Novel Psychoactive Substances (NPS) presents a significant challenge for both diagnosis and treatment, particularly due to the complex psychotic states they can induce. This paper explores the concept of lysergic psychoma, rooted in Bonhoeffer's exogenous psychosis model, and its relevance to modern substance-induced psychoses. Lysergic psychoma, characterized by...
The relationship between substance use and the onset of psychosis has been a subject of clinical and academic debate for centuries. The potential for cannabis to trigger psychosis was first suggested by Grose in 1772, who documented issues related to cannabis use in India (1). Karl Jaspers later explored this connection in his Allgemeine Psychopathologie (1959), describing toxic intoxications...
This study explores the psychotic-like experiences (PLEs) associated with recreational ketamine use among young adults. Ketamine, initially introduced as an anesthetic, is now widely used recreationally for its dissociative effects, raising concerns about its impact on mental health. Ten participants aged 18-24, who used ketamine recreationally multiple times a week, were assessed using the...
Substance use and the emergence of Novel Psychoactive Substances (NPS) present a significant public health challenge and diagnostic dilemma, particularly in the context of psychosis. The increasing availability of psychoactive substances among youth has led to a rise in Substance Use Disorders (SUDs), with profound implications for mental health. This paper explores the psychopathological...
Cannabis use represents a significant environmental risk factor for psychotic disorders, with emerging evidence suggesting complex interactions between cannabinoid exposure, dissociative experiences, and fundamental disturbances of self-experience (self-disorders) in early psychosis. This systematic review examines the phenomenological and neurobiological relationships among dissociation,...
BACKGROUND: Cannabis is the most used recreational drug worldwide. Its use can increase the risk of developing psychotic disorders and exacerbate their course. However, little is known about the relationship between psychosis and withdrawal and the literature is still scarce. CASE PRESENTATION: In this study, based on an analysis of 4 patients referred to our mental health department and...
Substance-induced psychosis (SIP) is an increasingly prevalent and complex condition that presents significant diagnostic and therapeutic challenges. With the rising use of novel psychoactive substances (NPSs) and potent traditional compounds like cannabis and cocaine, particularly among adolescents and young adults, understanding the mechanisms and clinical manifestations of SIP has become...