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 distinctions between substance-induced psychoses (SIPs) and endogenous psychoses, such as schizophrenia, from a phenomenological perspective. We emphasize three key aspects: dissociation, mental automatism, and temporality, to elucidate the underlying mechanisms of these conditions. Dissociation, as a psychopathological organizer, is central to exogenous psychoses, particularly those triggered by NPS. This phenomenon leads to a fragmentation of consciousness, detachment from reality, and disintegration of identity, distinct from the spaltung observed in endogenous psychoses. The concept of mental automatism, as theorized by De Clerambault, is also explored, highlighting its role in the early stages of exogenous psychoses, where cognitive disruptions precede delusions and hallucinations. Furthermore, the temporal experience in SIPs is characterized by a disconnection from past and future, trapping individuals in an "eternal present." This contrasts with the fragmented temporality observed in schizophrenia, where patients struggle to maintain a coherent narrative of their lives. The phenomenological approach provides critical insights into the clinical differentiation between SIPs and Primary Psychotic Disorders (PPDs), emphasizing the need for targeted interventions that address the specific temporal and cognitive disruptions in substance-induced conditions. In conclusion, this paper underscores the importance of integrating phenomenological psychopathology into clinical practice, particularly in the face of the evolving landscape of substance use and psychosis. Understanding the di Individuals with chronic and heavy substance use, including cannabis, amphetamines, psychedelics, and cocaine, are at particularly elevated risk ( 35 ). There is growing recognition that substance use is linked to the onset of psychosis, which can manifest during substance use and persist even after withdrawal or cessation. Individuals experiencing SIP often seek urgent assistance, either by contacting law enforcement or ambulance services or by presenting themselves at emergency rooms, as they or their family and friends perceive an immediate need for intervention. Heavy and prolonged substance use can abruptly alter an individual’s perception and cognition, resulting in frightening experiences that may not be recognized as stemming from acute intoxication and necessitate urgent attention ( 37 , 38 ). Some individuals may endure substance-induced psychotic symptoms for extended periods before seeking help. There is a dearth of research dedicated to differentiating Substance-Induced Psychosis (SIP) from Primary Psychotic Disorders (PPD), particularly in terms of elucidating potential divergent trajectories and outcomes ( 39 – 41 ). SIP is characterized by the emergence of psychotic symptoms, such as hallucinations and delusions, during or shortly after substance intoxication or withdrawal, with symptoms resolving within a specified timeframe (1 month). The DSM-5 stipulates that psychotic symptoms in SIP should be more severe than those expected during intoxication or withdrawal and should necessitate healthcare intervention. Additionally, there should be a lack of insight into hallucinations and delusions. However, it is notable that this definition does not explicitly encompass negative symptoms, potentially overlooking a significant aspect of clinical presentation. Central to de Clérambault’s work was his belief in a direct correspondence between observed clinical manifestations of mental automatism and underlying neurological disturbances responsible for these phenomena. He adhered strictly to an organicist perspective, positing that mental automatism resulted from negative reactions to factors like infection, intoxication, or tumors. Given the mechanistic logic of automatism, he reasoned its origins must be mechanical, not psychological. De Clérambault dismissed psychological explanations as highly implausible and seemed indifferent to causation questions, using ‘mechanism’ perhaps more metaphorically ( 107 ). Drawing on Jacksonian theories, de Clérambault believed that intoxications could release activities typically controlled by higher inhibitory centers, resulting in autonomous, seemingly spontaneous automatic phenomena. De Clérambault asserted that these mental automatisms had a significant organic, biological component, with the patient’s critical ego passively observing the automatism, overlaid by delusion. Kurt Schneider’s construct ( 100 ) was developed after the contribution of de Clérambault, and builds on Jaspers’ notion of mental automatism as a disturbance of ego consciousness. Characteristic Endogenous Psychoses (Spaltung) Exogenous Psychoses (Dissociation) Term Origin Derived from Bleuler, used to describe the psychic disintegration typical of schizophrenia Derived from Janet, referring to the fragmentation of consciousness and disconnection linked to traumatic factors Definition Splitting of the psyche involving a stable and profound separation between internal psychic complexes Temporary and dynamic disaggregation of consciousness and psychic functions in response to external factors Mechanism A stable fracture towards the center of the psyche, with loss of semantic and syntactic connections Oscillation between dissociative states and partial reintegration of consciousness Clinical Manifestations Breakdown of logical associations, emergence of false ideas, and isolation from reality (autism) Twilight states, confusion, and loss of contact with reality during intoxication Role of temporality

Cannabis and temporal disintegration in experienced and naive subjects. The effects of 3.3 and 6.6 milligrams of Delta(9)-tetrahydrocannabinol and of placebo on performance of three cognitive tasks were compared for naive subjects and experienced cannabis smokers. No differences in performance or reported subjective effects were found between these two groups. A significant decrement was found following dosage at both levels, replicating earlier findings of temporal disintegration during cannabis intoxication. Published in Science (New York, N.Y.) (1973)

[Effect of cannabis use on health]. Impairment in short-term memory and lingering deficit in psychomotor performance are but two of the acute cannabis intoxication components that may have long-term consequences. The former because it affects learning and the latter because it interferes with proper handling of motor vehicles. The most frequently observed complication of cannabis inebriation, however, is a short-lasting acute psychological disturbance with symptoms of panic, paranoid apprehension and personality disorganization. This type of reaction is often not dose-related, and could appropriately be termed "pathological intoxication". In addition to the acute effects of cannabis on mental performance and behaviour, this paper reviews the psychiatric consequences of chronic use and the accumulated evidence on organic toxicity associated with it: residual cognitive deficit, lethargic symptoms, cannabis psychosis, respiratory, gastro-intestinal and cardiovascular complications, as well as effects on immune response and gonadal functions, are discussed. Also included are reviews on the pharmacology and therapeutic potential of cannabinoids.

Cannabis can be associated with acute cognitive changes. Acute cannabis intoxication results in impaired concentration, impaired attention, impulsivity, and decreases in working memory. In adults, most of the effects wear off with abstinence. Impulsivity and long-term impairment in decision making is seen in heavy cannabis users. In adolescents, cannabis use is more closely associated with cognitive problems. Cannabis use should be avoided in younger people. Cannabis use should be avoided in younger people. Free Downloads for Offline Access Free Download Presentation File (PPTX) Free Download Audio File (MP3) Free Download Video (MP4) Free Downloads Slides and Transcript Slide 1 of 13 Video 3: Cannabis and Cognition. Now, we'll ask the question, does cannabis use cause cognitive deficits? Slide 2 of 13 Certainly, acute cannabis intoxication is associated with impaired memory, impaired attention, decreases in concentration, impaired coordination, and changes in judgment. Studies have shown that chronic cannabis users can develop tolerance to some of these acute effects of intoxication. References: Crean, R. D., Tapert, S. F., Minassian, A., MacDonald, K., Crane, N. A., & Mason, B. J. (2011). Effects of chronic, heavy cannabis use on executive functions. Journal of Addiction Medicine, 5(1), 9-15. Free Files Download PDF and other files Free downloads for "Cannabis and Cognition" Free Download Now Success! Check your inbox, we sent you all the materials there. Slide 3 of 13 But now we want to ask the question, are there long-term effects on cognition that come with cannabis use? Research studies have investigated whether cannabis use is associated with effects on cognition that persist after the acute intoxicating effects of THC have subsided. It's not known which came first, the cognitive deficit or the cannabis use. It's possible that people with impulsive decision making are more likely to be using cannabis heavily and regularly as adults. References: Canadian Centre on Substance Use and Addiction. (2019). Clearing the smoke on cannabis: Regular use and cognitive functioning (6th). https://www.ccsa.ca/clearing-smoke-cannabis-regular-use-and-cognitive-functioning Free Files Download PDF and other files Free downloads for "Cannabis and Cognition" Free Download Now Success! Check your inbox, we sent you all the materials there. Slide 5 of 13 What advice can we give to our patients? We know that intermittent light cannabis use is not likely to have serious long-term effects on cognition. Those who use cannabis regularly are likely to perform reasonably well on routine everyday life tasks, but they might encounter difficulties when performing complex tasks that are novel, require learning or rely https://www.ccsa.ca/clearing-smoke-cannabis-regular-use-and-cognitive-functioning Slide 6 of 13 It's also key to recognize that the interaction of reduced executive function or impulsive decision making in cannabis use has a higher likelihood of leading to a cannabis use disorder. References: Canadian Centre on Substance Use and Addiction. (2019). Clearing the smoke on cannabis: Regular use and cognitive functioning (6th). https://www.ccsa.ca/clearing-smoke-cannabis-regular-use-and-cognitive-functioning Free Files Download PDF and other files Free downloads for "Cannabis and Cognition" Free Download Now Success! Check your inbox, we sent you all the materials there. Slide 7 of 13 Now, I'll move on to cannabis and cognition in children. In young people, cannabis use may have long-term effects. Some studies show that cannabis use in individuals under the age of 17 is associated with impairments in executive functioning, abstract reasoning, verbal fluency, learning and memory, and that these effects persist beyond acute intoxication. References: Canadian Centre on Substance Use and Addiction. (2019). Clearing the smoke on cannabis: Regular use and cognitive functioning (6th). https://www.ccsa.ca/clearing-smoke-cannabis-regular-use-and-cognitive-functioning Slide 8 of 13 However, this research again cannot show a causal effect. We don't know if cannabis is causing the cognitive deficits since it's possible that the cognitive issues preceded cannabis use. References: Canadian Centre on Substance Use and Addiction. (2019). Clearing the smoke on cannabis: Regular use and cognitive functioning (6th). https://www.ccsa.ca/clearing-smoke-cannabis-regular-use-and-cognitive-functioning Free Files Download PDF and other files Free downloads for "Cannabis and Cognition" Free Download Now Success! Check your inbox, we sent you all the materials there. https://www.ccsa.ca/clearing-smoke-cannabis-regular-use-and-cognitive-functioning Slide 10 of 13 So, the key point here is that cannabis can be associated with acute cognitive changes. Acute intoxication results in impaired concentration, impaired attention, impulsivity, and decreases in working memory. Free Files Download PDF and other files Free downloads for "Cannabis and Cognition" Free Download Now Success! Check your inbox, we sent you all the materials there. Slide 11 of 13 In adults, most of these effects will wear off with abstinence. However, impulsivity and long-term impairment in decision making is seen in heavy cannabis users. Slide 12 of 13 In adolescents, cannabis use is more closely associated with cognitive problems. Cannabis use is best avoided in this age group. Free Files Download PDF and other files Free downloads for "Cannabis and Cognition" Free Download Now Success! Check your inbox, we sent you all the materials there. Slide 13 of 13 Next Section 04. Cannabis and Addiction Earn credits for your learning! No CMEs available Certification expiration date: April 1, 2025 CME Information Learning Objectives: After completing this activity, the learner will be able to: Discuss the impact of cannabis use on psychiatric symptoms and cognition.

Cannabis Effects on Brain Morphology in Aging Marijuana (Cannabis sativa) is the most widely used illicit drug worldwide, with 17.4 million Americans reporting past month use in 2010 and 4.6 million meeting criteria for dependence, underscoring the public health importance of understanding the biological implications of use. How heavy cannabis use affects brain structure and cognitive performance in late life is unknown. The ongoing maturation in the adolescent brain, including the developmental circuitry underlying memory performance and executive control puts the adolescent brain at high risk for detrimental effects of heavy cannabis use. With the aging of the 'baby boomer' generation, many people who used cannabis heavily as adolescents are now entering their senior years when age-related cognitive decline may begin. Cannabis use doubled in less than a decade during the 1970's when 38% of those surveyed in the U.S. Survey on Drug Abuse reported using cannabis and 12% of those users reported using cannabis more than 20 times a month.

Cannabis and cerebral hemispheres: a chrononeuropsychological study. This work is a study of the possibility that chronic consumption of derivatives of cannabis can affect the cognitive styles and the brain, altering the relations between both cerebral hemispheres. The results indicate that the Basic Rest-Activity Cycle (BRAC) between two different cognitive styles is not altered in the subjects of the control group; however, there is an alteration in the BRAC of the cerebral hemispheres in the chronic users of hashish. Published in The International journal of neuroscience (1991)