The Loss of Spatiality and Temporality in Twilight Consciousness: The Emergence of Exogenous Psychosis Induced by Novel Psychoactive Substances.

BACKGROUND: The state of twilight consciousness is marked by a focused narrowing of awareness, maintaining vigilance and attention while simultaneously experiencing perceptual shifts in the surrounding environment. It is crucial to recognize that this twilight state represents not just a contraction but also an expansion of conscious experience. SUMMARY: Substances of abuse, particularly new psychoactive substances, play a significant role in inducing this twilight state. They achieve this by deconstructing essential components of consciousness, such as the perception of time and space. KEY MESSAGE: This paper aimed to explore the phenomenon of the twilight state of consciousness and shed light on how new psychoactive substances can alter the perception of time and space during this twilight phase, potentially triggering exogenous psychosis. This comprehensive inquiry employs a phenomenological approach to the study of consciousness, recognizing it as the primary tool for ascribing significance to this intricate yet often overlooked aspect of psychopathology.

Effects of seasonality in emergency admissions for mental disorders: two years of clinical experience.

OBJECTIVES: This retrospective study, conducted in Turin, Italy, between January 2021 and February 2023, investigates the impact of seasonal heatwaves on emergency department (ED) admissions for mental disorders. METHODS: Through the analysis of data from 2,854 patients, this research found a significant link between the occurrence of heatwaves, especially from June to August, and an elevated rate of ED admissions for psychiatric conditions. RESULTS: The data indicate a clear seasonal pattern, with admissions peaking during the hot months and diminishing in the colder months. Particularly, the study delineates an enhanced correlation between heatwaves and admissions for severe psychiatric disorders, such as bipolar disorder, major depression, personality disorders, and schizophrenia, accounting for 1,868 of the cases examined. This correlation was most pronounced among individuals aged 50-59 years. CONCLUSIONS: The results of this study highlight a critical association between the incidence of seasonal heatwaves and an uptick in ED visits for psychiatric disorders, with a distinct impact on severe cases. It underscores the urgency for healthcare systems to anticipate seasonal fluctuations in psychiatric ED admissions and to allocate resources effectively to support patients during peak periods.

Two-Injection Start Regimen of Long-Acting Aripiprazole in 133 Patients With Schizophrenia.

PURPOSE/BACKGROUND: Based on a population-pharmacokinetic model, the European Medicines Agency has recently approved a simplified starting strategy of aripiprazole once a month (AOM), injectable and long-acting antipsychotic, with two 400 mg injections and a single oral 20 mg dose of aripiprazole, administered on the same day, instead of 1 injection and 14 daily administrations of concurrent oral aripiprazole. However, to our knowledge, no previous study has reported the safety and tolerability of this regimen in real-world patients. METHODS/PROCEDURES: We retrospectively reviewed medical records of 133 patients who received the newly approved 2-injection start regimen as part of their standard care in 10 Italian clinical centers. FINDINGS/RESULTS: Adverse effects were mild or moderate, with no clinically evident difference from the adverse effects observed in previous trials where AOM was started with a single injection followed by 14 days of orally administered aripiprazole. None of the patients who started AOM after the 2-injection start regimen experienced severe adverse effects or severe adverse effects. IMPLICATIONS/CONCLUSIONS: The coadministration of 2 injections of 400 mg aripiprazole and 20 mg oral aripiprazole was not associated with safety concerns beyond those reported after a single injection followed by 14 days of orally administered aripiprazole. Our results should be interpreted with caution, due to the limited sample size and to the retrospective design of the study.

Dissociation and Temporality in Substance Abuse: A Clinical Phenomenological Overview.

The term "dissociation" encompasses a wide array of symptoms and phenomena, all sharing the common characteristic of involving altered states of consciousness where an individual temporarily loses the sense of continuity of their own identity. In the context of addiction pathology, however, the dissociative paradigm remains a topic of ongoing debate. It fluctuates between the description of individual dissociative symptoms and the notion of post-traumatic dissociation as a structural process. This process involves fragmentation that extends beyond the confines of perception and experience within a singular moment, instead ensuring a persistent discontinuity of the self throughout one's existence. Pathological addiction stresses the question of the donation of sense in this deep and dramatic experience; it situates individuals within a compressed and constricted realm of vital space, alongside a frozen perception of time. Within this context, every emotion, sensation, and comprehension becomes impaired. Consequently, we have embarked on a journey starting with a historical analysis: the aim was to construct an elucidative framework for the dissociative paradigm in the context of addiction. This involves an in-depth exploration of the fundamental constructs of trauma and temporality, examined through the lens of phenomenological perspective.

CANNABIS USE AND SUICIDE IN NON-AFFECTIVE PSYCHOSIS: A MINI-REVIEW OF RECENT LITERATURE.

Proof of correlation between psychotic spectrum disorders and suicide are found in literature, as well as between cannabis use disorder (CUD) and suicide and between CUD and schizophrenia. The study population of the selected papers consists of subjects diagnosed with schizophrenia spectrum or cannabis or SCs induced psychosis. Our objective is to assess how suicide risk (defined as suicidal ideation/attempt or death by suicide) in this population may vary with exposure to cannabis or one of its main active compounds. We searched PubMed, Scopus and Psycinfo database from January 2010 to February 2022. Study designs of the included articles are distributed as follows: 6 cross-sectional studies, 3 cohort studies, 1 case-control studies, 1 randomized double-blind study, 1 case report. Selected cohort studies seem to agree in identifying an increased suicide risk in patients with schizophrenia spectrum disorders when exposed to cannabis use. The case-control study and selected cross-sectionals provide contradictory data. However, qualitative analysis seem to point toward a positive correlation between cannabis use and increased suicidal risk in patients with schizophrenia spectrum disorders. In conclusion, emerging data on the correlation between cannabis use and suicide risk in patients with schizophrenia or other schizophrenic spectrum disorders are insufficient to draw firm conclusions. Nonetheless these studies seem to suggest a positive correlation of cannabis use with increased suicide risk, particularly regarding first episode psychosis (FEP) and male gender. Clinicians should be aware of the possibility of a higher risk of suicidal behavior associated specifically with cannabis use for men and patients during FEP.

Agomelatine Increases BDNF Serum Levels in Depressed Patients in Correlation with the Improvement of Depressive Symptoms.

BACKGROUND: Agomelatine modulates brain-derived neurotrophic factor expression via its interaction with melatonergic and serotonergic receptors and has shown promising results in terms of brain-derived neurotrophic factor increase in animal models. METHODS: Twenty-seven patients were started on agomelatine (25mg/d). Venous blood was collected and brain-derived neurotrophic factor serum levels were measured at baseline and after 2 and 8 weeks along with a clinical assessment, including Hamilton Depression Rating Scale and Snaith-Hamilton Pleasure Scale. RESULTS: Brain-derived neurotrophic factor serum concentration increased after agomelatine treatment. Responders showed a significant increase in brain-derived neurotrophic factor levels after 2 weeks of agomelatine treatment; no difference was observed in nonresponders. Linear regression analysis showed that more prominent brain-derived neurotrophic factor level variation was associated with lower baseline BDNF levels and greater anhedonic features at baseline. CONCLUSIONS: Patients affected by depressive disorders showed an increase of brain-derived neurotrophic factor serum concentration after a 2-week treatment with agomelatine. The increase of brain-derived neurotrophic factor levels was found to be greater in patients with lower brain-derived neurotrophic factor levels and marked anhedonia at baseline.

BDNF serum levels in subjects developing or not post-traumatic stress disorder after trauma exposure.

Post-traumatic stress disorder (PTSD) is a syndrome resulting from exposure to a severe traumatic event that poses threatened death or injury and produces intense fear and helplessness. The neural structures implicated in PTSD development belong to the limbic system, an important region for emotional processing. Brain-derived neurotrophic factor (BDNF) is a neurotrophin that serves as survival factor for selected populations of central nervous system (CNS) neurons and plays a role in the limbic system by regulating synaptic plasticity, memory processes and behavior. Impaired BDNF production in the brain can lead to a variety of CNS dysfunctions including symptoms associated with PTSD. However, so far fewer studies have investigated this neurotrophin in patients with PTSD. Furthermore, given the multiple role of BDNF in various CNS disorders, it cannot be excluded that traumatic events per se may influence neurotrophin levels, without a direct association to the PTSD syndrome. To elucidate these issues, in this study we analyzed BDNF serum levels in two groups of subjects: patients with trauma exposure who developed PTSD, and subjects with trauma exposure who did not develop PTSD. We found that BDNF serum levels were lower in PTSD patients as compared to related control subjects. Thus, these data suggest that BDNF might be involved in pathophysiology of PTSD and consequently therapeutic approaches aimed at restoring BDNF serum levels may be beneficial to this pathology.

Rethinking Mental Automatism: De Clérambault's Theory in the Age of Novel Psychoactive Drugs: Psychotropic Effects and Synthetic Psychosis.

The widespread use of novel psychoactive substances (NPSs)-defined as new narcotic or psychotropic agents not classified under the Single Convention on Narcotic Drugs of 1961 or the Convention on Psychotropic Substances of 1971-poses a significant challenge to contemporary mental health paradigms due to their impact on psychiatric disorders. This study revisits and expands upon the theory of mental automatism as proposed by Gaëtan Gatian de Clérambault, aiming to elucidate the psychopathological mechanisms underlying substance-induced psychoses (SIP) and their distinction from non-induced psychoses (schizophrenia and related disorders). Through a phenomenological and clinical investigation, we explore the relevance of mental automatism in the development of toxic psychoses, drawing upon the historical and contemporary literature. This research highlights the psychopathological distinctions between induced and non-induced psychoses and the transition mechanisms from acute to chronic psychosis states. De Clérambault's theory, supplemented by Janet, Jackson, and Bonhoeffer's contributions, provides a foundational framework for understanding the genesis of SIP. Our findings suggest that NPS consumption, particularly among adolescents and psychiatric patients, significantly correlates with increased risks of SIP, marked by a transition to chronicity influenced by biological lesions triggered by substance use. Furthermore, we propose a comprehensive framework for SIP, integrating mental automatism, psychopathological distinctions, and transition mechanisms. This framework aims to refine diagnostic criteria and therapeutic approaches, addressing gaps in clinical practice and research. The study underscores the need for a nuanced understanding of SIP, advocating for a paradigm shift in psychiatric assessment and treatment approaches to better address the complexities of substance-induced mental health disorders.

Comparative analysis of third-generation antipsychotics in first-episode schizophrenia: efficacy, safety, and cognitive impacts. A narrative review.

BACKGROUND AND OBJECTIVES: Schizophrenia is a chronic, complex mental health disorder requiring effective management to mitigate its broad personal and societal impacts. This narrative review assesses the efficacy, effectiveness, and side effects of third-generation antipsychotics (TGAs) like aripiprazole, brexpiprazole, and cariprazine, focusing on their use in first-episode schizophrenia. These drugs aim to reduce side effects typical of earlier antipsychotics while more effectively addressing positive and cognitive symptoms. METHODS: Our extensive literature review, using PubMed and Scopus, includes randomized controlled trials and observational studies, showing TGAs may match older antipsychotics in efficacy with fewer side effects, notably in reducing extrapyramidal symptoms and enhancing cognitive outcomes. RESULTS: Aripiprazole appears effective in both acute and maintenance phases of schizophrenia, while brexpiprazole and cariprazine show potential in managing negative symptoms and improving social functioning, essential for patient recovery. CONCLUSIONS: This review emphasizes the need for personalized treatment and further research to fully determine the long-term benefits and safety of TGAs. These findings can inform clinical decisions and underline the ongoing need for innovation in schizophrenia pharmacotherapy.

Third-Generation Antipsychotics and Lurasidone in the Treatment of Substance-Induced Psychoses: A Narrative Review.

This narrative review explores the efficacy and tolerability of third-generation antipsychotics (TGAs)-aripiprazole, cariprazine, brexpiprazole, and lurasidone-for the management of substance-induced psychosis (SIP). SIP is a psychiatric condition triggered by substance misuse or withdrawal, characterized by unique features distinct from those of primary psychotic disorders. These distinctive features include a heightened prevalence of positive symptoms, such as hallucinations and delusions, in addition to a spectrum of mood and cognitive disturbances. This review comprehensively investigates various substances, such as cannabinoids, cocaine, amphetamines, and LSD, which exhibit a greater propensity for inducing psychosis. TGAs exhibit substantial promise in addressing both psychotic symptoms and issues related to substance misuse. This review elucidates the distinctive pharmacological properties of each TGA, their intricate interactions with neurotransmitters, and their potential utility in the treatment of SIP. We advocate for further research to delineate the long-term effects of TGAs in this context and underscore the necessity for adopting an integrated approach that combines pharmacological and psychological interventions. Our findings underscore the intricate and multifaceted nature of treating SIP, highlighting the potential role of TGAs within therapeutic strategies.

Efficacy and suitability of adding short-term psychodynamic psychotherapy (STPP) to pharmacotherapy in patients with depressive disorders: a systematic review.

INTRODUCTION: Recent guidelines on depressive disorders suggest a combination of antidepressants and psychotherapy in case of moderate to severe symptomatology. While cognitive behavioral therapy and interpersonal therapy are the most investigated interventions, psychodynamic psychotherapies have been less explored. OBJECTIVE: The aim of this paper is to systematically review literature data on the efficacy of shortterm psychodynamic psychotherapy (STPP) in combination with antidepressants in the treatment of depressive disorders, focusing both on short and on long-term results and on potential moderators that could influence its effectiveness. METHODS: The systematic review was conducted using the PRISMA guidelines. Databases searched were PubMed, Ovid, Scopus, and Cochrane Library, from inception to August 2023. RESULTS: Adding STPP to medications in the first six months of treatment didn't influence remission rates, but improved acceptability, work adjustment, interpersonal relationships, social role functioning, hospitalization rates and cost-effectiveness. After 12 months, a significant difference in remission rates arised, favouring combined therapy. In a long-term perspective, adding STPP to pharmacotherapy reduced the recurrence rate by almost 50%. STPP has proven to be more effective in longer depressive episodes, in more severe depressions and in patients with a childhood abuse history. Instead, STPP had no impact on major depressive disorder with comorbid Obsessive-Compulsive Disorder (OCD). CONCLUSIONS: Combining STPP with antidepressants appeared to be helpful both in a short-term and in a long-term perspective. Still, there are few rigorous studies with large samples and further research is needed to identify which subgroups of patients may benefit more from STPP.

Examining Lurasidone Efficacy in Patients with Schizophrenia Spectrum Illness and Concurrent Alcohol and Substance Use Disorder: A Prospective, Multicentric, Real-World Investigation.

Background: Dual disorders (DD) entail the coexistence of a substance use disorder (SUD) and another mental health condition, often within psychotic and affective disorders. This study aims to evaluate lurasidone, an innovative atypical antipsychotic, in individuals diagnosed with schizophrenia spectrum disorder and concurrent comorbidities of alcohol use disorder/substance use disorder (AUD/SUD). Methods: A cohort of 23 subjects diagnosed with schizophrenia spectrum disorder and comorbid AUD/SUD underwent psychometric assessments at baseline (T0) and one-month (T1) post-lurasidone initiation. Results: Lurasidone exhibited significant reductions in psychopathological burden, evidenced by decreased total PANSS scores (Z = 2.574, p = 0.011). Positive symptoms, substance craving (VAS Craving; Z = 3.202, p = 0.001), and aggressivity (MOAS scale; Z = 2.000, p = 0.050) were notably reduced. Clinical Global Impression (CGI) scores significantly improved (Z = 2.934, p = 0.003). Quality of life enhancements were observed in SF-36 subscales (energy, emotional well-being, and social functioning) (p < 0.05) and Q-LES-Q-SF scale (Z = -2.341, p = 0.021). A safety analysis indicated lurasidone's good tolerability, with only 8.7% reporting discontinuation due to side effects. Conclusions: This study offers initial evidence supporting lurasidone's efficacy and safety in dual diagnoses, highlighting positive effects on psychopathology, substance craving, and quality of life. These findings emphasize the need for tailored, comprehensive treatment strategies in managing the complexities of this patient population.

Investigating the Effectiveness of Brexpiprazole in Subjects with Schizophrenia Spectrum Illness and Co-Occurring Substance Use Disorder: A Prospective, Multicentric, Real-World Study.

BACKGROUND: Dual disorders (DDs) involve the coexistence of a substance use disorder (SUD) with another mental illness, often from the psychotic and affective categories. They are quite common in clinical practice and present significant challenges for both diagnosis and treatment. This study explores the effectiveness of brexpiprazole, a third-generation antipsychotic, in an Italian sample of individuals diagnosed with schizophrenia spectrum disorder and a comorbid SUD. METHODS: Twenty-four patients, diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and enrolled in several Italian hospitals, underwent a psychometric assessment at baseline (T0) and one month (T1) after starting brexpiprazole treatment administered at a mean dosage of 2 mg/day. RESULTS: Brexpiprazole demonstrated significant reductions in psychopathological burden (Positive and Negative Syndrome Scale/PANSS total score: p < 0.001). Positive (p = 0.003) and negative (p = 0.028) symptoms, substance cravings (VAS craving: p = 0.039), and aggression (MOAS scale: p = 0.003) were notably reduced. Quality of life improved according to the 36-item Short Form Health Survey (SF-36) subscales (p < 0.005). CONCLUSIONS: This study provides initial evidence supporting brexpiprazole's efficacy and safety in this complex patient population, with positive effects not only on psychopathology and quality of life, but also on cravings. Further studies involving larger cohorts of subjects and extended follow-up periods are needed.

Enhanced BDNF serum levels in patients with severe pathological gambling.

Although the pathophysiology of gambling is unknown, an involvement of midbrain dopaminergic pathway has been hypothesized. In this study, the association between brain-derived neurotrophic factor (BDNF) and pathological gambling was investigated. We measured BDNF serum levels in (1) video players (n=10); (2) card players (n=9); (3) mixed players (n=21; both video and card players) and (4) age-matched controls (n=18). Mixed players had increased BDNF serum levels as compared to controls and higher South Oaks Gambling Screen score as compared to card or video players. Thus, the data demonstrate that patients affected by severe pathological gambling show enhanced BDNF serum levels.

Lurasidone in first-episode psychosis with predominant depressive symptoms: a case report.

Lurasidone is an atypical antipsychotic approved for the treatment of schizophrenia and bipolar depression. It seems to have an antidepressant effect due to 5-HT7 as well as 5-HT2A and 5-HT1a receptor affinity. Here we present a case of a 19-year-old male patient with first-episode psychosis (FEP) and predominant depressive symptoms. Remarkable clinical and functional improvement was observed 3 months after the beginning of lurasidone treatment. The patient's depressive symptoms disappear with a dramatic reduction of psychotic ones, with good tolerance of the drug and without adverse effects. Lurasidone seems to be a promising treatment option for FEP with predominant depressive symptoms.

Neurotrophic Factors In Cannabis-Induced Psychosis: An Update.

BACKGROUND: Cannabis is the most widely used illicit substance. Numerous scientific evidence confirm the strong association between cannabis and psychosis. Exposure to cannabis can induce the development of psychosis and schizophrenia in vulnerable individuals. However, the neurobiological processes underlying this relationship are unknown. Neurotrophins are a class of proteins that serve as survival factors for central nervous system (CNS) neurons. In particular, nerve growth factor (NGF) plays an important role in the survival and function of cholinergic neurons while brain-derived neurotrophic factor (BDNF) is involved in synaptic plasticity and the maintenance of midbrain dopaminergic and cholinergic neurons. Glial Cell Derived Neurotrophic Factor (GDNF) promotes the survival of midbrain dopaminergic neurons and Neuregulin 1 (NrG-1) contributes to glutamatergic signals regulating the N-methyl-D-aspartate (NMDA). They have a remarkable influence on the neurons involved in the Δ-9-THC (tethra-hydro-cannabinol) action, such as dopaminergic and glutamatergic neurons, and can play dual roles: first, in neuronal survival and death, and, second, in activity-dependent plasticity. METHODS: In this brief update, reviewing in a narrative way the relevant literature, we will focus on the effects of cannabis on this class of proteins, which may be implicated, at least in part, in the mechanism of the psychostimulant-induced neurotoxicity and psychosis. CONCLUSION: Since altered levels of neurotrophins may participate in the pathogenesis of psychotic disorders which are common in drug users, one possible hypothesis is that repeated cannabis exposure can cause psychosis by interfering with neurotrophins synthesis and utilization by CNS neurons.

Internet Gaming Disorders and Early Onset Psychosis in Young People: A Case Study and Clinical Observations.

BACKGROUND: Over the last ten years, the video game industry has grown exponentially, involving about 2.5 billion young adults in the world. The estimated global prevalence of gaming addiction has been reported to be 3.5% ranging from 0.21% to 57.5% in the general population. Moreover, during the recent COVID-19 pandemic period, school closures and stay-at-home measures have also further increased the opportunities for prolonged and intensified playing of video games. Little is known about the relationship between IGD and psychosis, and the literature is still scarce. Some characteristics of patients with psychosis, particularly those with a first-episode psychosis (FEP), may suggest that these individuals would be particularly liable to develop IGD. CASE PRESENTATION: We report two cases of young patients with to Internet gaming disorder, experiencing early onset psychosis treated with antipsychotic therapy. CONCLUSION: Although it is difficult to show the specific mechanisms underlying the psychopathological alterations in IGD, it is clear that excessive exposure to video games could be a risk factor for precipitating psychosis especially in a vulnerable age group such as adolescence. Clinicians should be aware of the possibility of a higher risk of psychotic onset associated specifically with gaming disorders in very young people.

First episode psychosis with and without the use of cannabis and synthetic cannabinoids: Psychopathology, global functioning and suicidal ideation and antipsychotic effectiveness.

BACKGROUND: Natural Cannabis (NC) and Synthetic Cannabinoids (SCs) use can increase the risk of developing psychotic disorders and exacerbate their course. AIMS: To examine the differences between psychoses not associated with cannabis use and those associated with NC and SCs use, evaluating psychotic symptoms, global functioning, dissociative symptoms and suicidal ideation. METHODS: The sample of 61 patients with First Episode Psychosis (FEP) was divided into 3 groups: non-Cannabis users (non-users, N = 20); NC users (THC-users, N = 21); SCs users (SPICE-users, N = 20). Each group was assessed at FEP and after 3 and 9 months through specific psychopathological scales. RESULTS: THC-users, and even more SPICE-users, displayed much more severe positive symptoms than non-users. Negative symptoms were higher among non-users. After 9 months the non-users had recovered significantly better than SPICE-users in their global functioning. Dissociative symptoms were significantly greater in substance users. Finally, suicidal ideation was higher in SPICE-users than in both THC-users and non-users. DISCUSSION: The psychoses induced by NC and SCs showed different symptomatic pictures and outcomes from each other and when compared to the psychoses not associated with the use of substances; such knowledge could be relevant in identifying a specific drug treatment.

Aberrant salience in cannabis-induced psychosis: a comparative study.

Background: Natural Cannabis (NC) and Synthetic Cannabinoids (SCs) use can increase the risk and exacerbate the course of psychotic disorders. These could be influenced by the Aberrant Salience (AS) construct. It refers to an excess of attribution of meaning to stimuli that are otherwise regarded as neutral, thereby transform them into adverse, dangerous, or mysterious entities. This leads the patient to engage in aberrant and consequently incorrect interpretative efforts concerning the normal perception of reality and its relationship with our analytical abilities. AS appears to play a significant role in the onset and perpetuation of psychotic disorders. The internal conflict arising from aberrant attributions of significance leads to delusional thoughts, ultimately culminating in the establishment of a self-sustaining psychosis. Aims: To examine the differences between psychoses course not associated with cannabis use and those associated with NC-use and SCs-use, in terms of psychotic and dissociative symptoms, AS, global functioning and suicidal ideation. Methods: A sample of 62 patients with First Episode Psychosis (FEP) was divided into 3 groups: non cannabis users (non-users, N = 20); NC-users or rather Delta-9-tetrahydrocannabinol (THC) users (THC-users, N = 21); SCs-users, commonly referred to as SPICE-users (SPICE-users, N = 20). Each group underwent assessments at the onset of psychotic symptoms, as well as at the 3 months and 6 months marks, utilizing a range of psychopathological scales. These included the Positive and Negative Syndrome Scale (PANSS) for investigating psychotic symptoms, the Global Assessment of Functioning (GAF) scale for assessing overall functioning, the Dissociative Experiences Scale (DES-II) for measuring dissociative symptoms, the Scale for Suicide Ideation (SSI) for evaluating suicidal ideation and the Aberrant Salience Inventory (ASI) scale for gauging AS. Results: SPICE-users showed more severe and persistent positive symptoms, while negative symptoms were mostly represented among non-users. Non-users showed better recovery than SPICE-users in global functioning. All groups showed a decrease in both ASI scores and subscale scores. SPICE-users exhibited higher global AS scores and less improvement in this aspect compared to other groups. Conclusion: This study may help understanding the role of AS in both non-substance-related and substance-induced psychosis. This knowledge may lead clinician to a better diagnosis and identify patient-tailored psychopharmacological treatment.

Association between cannabis use and symptom dimensions in schizophrenia spectrum disorders: an individual participant data meta-analysis on 3053 individuals.

Background: The association between cannabis use and positive symptoms in schizophrenia spectrum disorders is well documented, especially via meta-analyses. Yet, findings are inconsistent regarding negative symptoms, while other dimensions such as disorganization, depression, and excitement, have not been investigated. In addition, meta-analyses use aggregated data discarding important confounding variables which is a source of bias. Methods: PubMed, ScienceDirect and PsycINFO were used to search for publications from inception to September 27, 2022. We contacted the authors of relevant studies to extract raw datasets and perform an Individual Participant Data meta-analysis (IPDMA). Inclusion criteria were: psychopathology of individuals with schizophrenia spectrum disorders assessed by the Positive and Negative Syndrome Scale (PANSS); cannabis-users had to either have a diagnosis of cannabis use disorder or use cannabis at least twice a week. The main outcomes were the PANSS subscores extracted via the 3-factor (positive, negative and general) and 5-factor (positive, negative, disorganization, depression, excitement) structures. Preregistration is accessible via Prospero: ID CRD42022329172. Findings: Among the 1149 identified studies, 65 were eligible and 21 datasets were shared, totaling 3677 IPD and 3053 complete cases. The adjusted multivariate analysis revealed that relative to non-use, cannabis use was associated with higher severity of positive dimension (3-factor: Adjusted Mean Difference, aMD = 0.34, 95% Confidence Interval, CI = [0.03; 0.66]; 5-factor: aMD = 0.38, 95% CI = [0.08; 0.63]), lower severity of negative dimension (3-factor: aMD = -0.49, 95% CI [-0.90; -0.09]; 5-factor: aMD = -0.50, 95% CI = [-0.91; -0.08]), higher severity of excitement dimension (aMD = 0.16, 95% CI = [0.03; 0.28]). No association was found between cannabis use and disorganization (aMD = -0.13, 95% CI = [-0.42; 0.17]) or depression (aMD = -0.14, 95% CI = [-0.34; 0.06]). Interpretation: No causal relationship can be inferred from the current results. The findings could be in favor of both a detrimental and beneficial effect of cannabis on positive and negative symptoms, respectively. Longitudinal designs are needed to understand the role of cannabis is this association. The reported effect sizes are small and CIs are wide, the interpretation of findings should be taken with caution. Funding: This research did not receive any specific grant or funding. Primary financial support for authors was provided by Le Vinatier Psychiatric Hospital.