Combined Predictors for the Diagnostic Transition from Acute and Transient Psychotic Disorder to Schizophrenia: A Retrospective Study.

Purpose: Acute and transient psychotic disorder (ATPD), a psychosis frequently diagnosed, can potentially evolve into chronic conditions like schizophrenia (SCZ) and other mental disorders. This study aimed to develop a predictive model based on clinical data to forecast the transition from ATPD to SCZ and to identify the predictive factors. Methods: According to the diagnostic criteria issued by the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10), 396 inpatients diagnosed with ATPD were collected in this study. The Cox proportional-hazards regression model was performed using demographic data, clinical characteristics, and inflammatory markers to identify independent predictors for subsequent diagnostic transition (SDT) to SCZ. Results: During the follow-up period, 43.69% (n = 173) of ATPD patients had their diagnoses revised to SCZ. The multivariate Cox regression analysis identified post-treatment monocyte count, post-treatment monocyte/lymphocyte ratio (MLR), and the presence of schizophreniform symptoms as significant predictors for the diagnostic revision. Time-dependent receiver operating characteristic (TimeROC) analyses were developed. The AUC value at the 5-year follow-up was 0.728 for combined predictors, 0.702 for post-treatment monocyte count, 0.764 for post-treatment MLR, and 0.535 for the presence of schizophreniform symptoms. Conclusion: The combined predictors had good predictive ability for the diagnostic transition from acute and transient psychotic disorder to schizophrenia.

Neuropsychiatric Adverse Effects of Trimethoprim-Sulfamethoxazole: A Rare Case of Acute Psychosis in an Immunocompetent Patient.

Trimethoprim-sulfamethoxazole (TMP-SMX) is a combination of two antibiotics used to treat various bacterial infections, generally well-tolerated but can rarely cause neuropsychological adverse effects, including psychosis. This case report describes a 69-year-old immunocompetent female who developed acute visual and auditory hallucinations three days after starting TMP-SMX for a urinary tract infection (UTI). The patient had a history of depression, successfully treated with mirtazapine a decade ago, and no other psychiatric or medical conditions. Laboratory tests and imaging were unremarkable. Symptoms resolved completely within two days of discontinuing TMP-SMX, suggesting a causal relationship. This case highlights the need for vigilance regarding the neuropsychiatric side effects of TMP-SMX, even in immunocompetent individuals, and underscores the importance of considering medication-induced psychosis in differential diagnoses. Further research is warranted to elucidate the mechanisms underlying this adverse drug reaction.

Psychosis risk for lesbian, gay, and bisexual individuals: systematic review and meta-analysis.

The social defeat hypothesis posits that low status and repeated humiliation increase the risk for psychotic disorders (PDs) and psychotic experiences (PEs). The purpose of this paper was to provide a systematic review of studies on risk of PDs and PEs among lesbian, gay, or bisexual (LGB) people and a quantitative synthesis of any difference in risk. PubMed, PsycINFO, Embase, and Web of Science were searched from database inception until January 30, 2024. Two independent reviewers assessed the eligibility and quality of studies, extracted effect sizes, and noted the results of mediation analyses. Using a random effects model we computed pooled odds ratios (ORs). Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. The search identified seven studies of PDs and six of PEs. As for PDs, the unadjusted (2.13; 95% confidence interval 0.72-6.34) and covariate-adjusted pooled OR (2.24; 1.72-3.53) were not significantly increased for LGB individuals. After exclusion of a study of limited quality, both the unadjusted pooled OR (2.77; 1.21-6.32) and the covariate-adjusted pooled OR (2.67; 1.53-4.66) were significantly increased. The pooled ORs were increased for PEs: unadjusted, pooled OR = 1.97 (1.47-2.63), covariate-adjusted, pooled OR = 1.85 (1.50-2.28). Studies of PE that examined the mediating role of several variables reported that the contribution of drug abuse was small compared to that of psychosocial stressors. The results of a study in adolescents suggested a protective effect of parental support. These findings suggest an increased psychosis risk for LGB people and support the social defeat hypothesis.

Personal relationships during and after an initial psychotic episode. First-person experiences.

BACKGROUND: Psychosis is often associated with loneliness, the absence of a confidant and a perceived lack of social support. In addition, the social isolation and solitude experienced can aggravate internalised stigma, depressive symptoms and/or suicidal tendencies, and worsen the course of the disorder. AIM: This study explores the experiences and perceptions of persons with psychosis concerning how their interpersonal relationships have evolved from the earliest symptoms of the disorder to its subsequent clinical stabilisation. METHOD: A qualitative content analysis was performed of the findings from five focus groups and six in-depth interviews (36 participants). RESULTS: In the prodrome and initial symptoms stage, five themes were coded: social withdrawal, loss of friends, loss of personal skills, communication difficulties and breakdown of life project. During the recovery phase, four themes were coded: family support, partner support, loneliness and the desire for more close relationships. Finally, during the clinical stabilisation phase, three themes were coded: the recovery of interpersonal relationships, including with peers; reconstruction of the life project and increased interpersonal sensitivity. CONCLUSIONS: These findings highlight the impact that psychosis can have on social life and show that recovery is also related to the development of maeningful interpersonal relationships.

Felt presence and its determinants in young adults: results from three independent samples.

Felt presence (FP) is a phenomenon that might appear in individuals with mental and neurological disorders as well as those without any specific morbidity. Some studies have indicated that FP is closely related to psychotic symptomatology. Yet, the mechanisms underlying its occurrence remain largely unknown. The present study aimed to disentangle as to whether FP is associated with widely known risk factors of psychosis. Data from three independent samples of non-clinical young adults were analyzed. Self-reports were administered to assess psychopathological symptoms (samples 1 - 3), neurodevelopmental risk factors for psychosis (sample 1), social defeat components (sample 2), childhood trauma and loneliness (sample 3). A total of 4782 individuals were surveyed across all three samples. Unadjusted analyses showed that the following factors are associated with higher odds of FP: obstetric complications, childhood trauma, non-right handedness, a lower education level, unemployment, minority status, humiliation, perceived constraints, and loneliness. However, only minority status and a lower level of education were associated with higher odds of FP after adjustment for other psychopathological symptoms, age, and gender. Importantly, hallucination-like experiences across all recorded modalities and paranoia were associated with higher odds of FP in all samples. Depressive symptoms were weakly associated with FP in two samples. Findings from the present study suggest that the majority of known risk factors for psychosis contribute to the emergence of FP through the effects on psychotic experiences. Low educational attainment and minority status might be the only risk factors independently contributing to the emergence of FP.

Effectiveness of Vitamin E in Treatment of Antipsychotic-Induced Tardive Dyskinesia and Extrapyramidal Symptoms: A Case Report.

Antipsychotic medications, while crucial in managing severe psychiatric disorders such as schizophrenia and bipolar disorder, are frequently associated with extrapyramidal symptoms (EPS) and tardive dyskinesia (TD). TD, characterized by repetitive, involuntary movements, especially of the face and limbs, poses a substantial clinical challenge due to its often irreversible nature. Conventional management strategies, including dose reduction and switching to atypical antipsychotics, frequently offer limited success, prompting exploration of alternative therapies. This case report highlights the effectiveness of vitamin E, a potent antioxidant, in treating a 28-year-old male with severe antipsychotic-induced EPS and TD, unresponsive to traditional therapies. The patient, who had been receiving paliperidone injections as part of his psychotic disorder treatment regimen, developed marked EPS, including muscle rigidity, a parkinsonian gait, significant motor disturbances as well as tardive dyskinesia. Despite discontinuation of paliperidone and initiation of procyclidine, propranolol, clonazepam, and omega-3 supplements, his symptoms persisted. Introduction of oral vitamin E at 400 IU daily led to a dramatic improvement, with an 80% reduction in EPS and TD symptoms within weeks. The patient's Abnormal Involuntary Movement Scale (AIMS) score decreased from 24 to 4, and his overall quality of life improved significantly. Gradual increase of vitamin E dosage to 1200 IU daily, coupled with tapering of other medications, eventually led to complete resolution of symptoms, as evidenced by an AIMS score of 0. The patient maintained symptom-free status during follow-up, with no recurrence of psychotic symptoms. This case underscores the potential role of vitamin E as a viable adjunctive treatment for TD, particularly in patients who do not respond adequately to conventional therapies. While the literature presents mixed evidence regarding vitamin E's effectiveness, this case adds to the growing body of research suggesting its benefits, especially when introduced early in the disease course. Further large-scale studies are warranted to establish the most effective treatment protocols and identify patient populations most likely to benefit from vitamin E therapy.

[Impact of the legalization of recreational cannabis on the risk of psychosis: A systematic review of the literature]. / Impact de la légalisation du cannabis à usage récréatif sur le risque de psychose : une revue systématique de la littérature.

INTRODUCTION: Cannabis is the most consumed illicit substance in Europe. Although its sale and use remain generally prohibited, European public policies have evolved in recent years by legalizing cannabis for medical use and considering its legalization for recreational use. However, in the literature there are arguments in favor of a particular relationship between cannabis consumption and the development of psychotic symptoms. Thus, since cannabis consumption tends to increase with legalization, the aim of this review was to investigate the impact of the legalization of cannabis for recreational use on the risk of psychosis in regions of the world already concerned. METHOD: A systematic review of the literature was carried out in April 2024 in the PubMed-Medline database according to PRISMA criteria. The sequence of keywords used was as follows: ("Cannabis" [Mesh] or cannabis) AND (("Psychotic Disorders" [Mesh] or Psychotic Disorders) or ("Schizophrenia Spectrum and Other Psychotic Disorders" [Mesh]) or ("Schizophrenia" [Mesh] or Schizophrenia)) AND legal use. The inclusion criteria applied for the selection of articles in this systematic review were: (1) any article investigating the potential impact of the legalization of cannabis for recreational use on the risk of psychosis (any type of psychosis diagnosed according to ICD-9, ICD-10, DSM-4 or DSM-5) by the intermediary of epidemiological (incidence or prevalence) and/or clinical (ambulatory consultations, emergency visits or hospitalizations) criteria, (2) any type of study (cross-sectional, longitudinal, prospective, retrospective, interventional and experimental) with a methodology including a temporal and/or geographic comparison of the risk of psychosis associated with the legalization of cannabis for recreational use with the exception of literature reviews and clinical cases descriptions, (3) absence of limitation for the age of the populations studied and for the date of publication, and (4) articles written in English or French. After evaluation by the two authors of the 160 articles identified, seven studies investigating the impact of the legalization of cannabis for recreational use on the risk of psychosis were included in this systematic literature review. RESULTS: Four of the studies showed no increase in the use of health services for psychosis following the legalization of cannabis for recreational use whereas three other studies highlighted a negative impact of the legalization of cannabis for recreational use on the risk of psychosis. All of these studies were carried out in North America and were characterized by a low level of scientific evidence. CONCLUSION: Given the complexity of assessing the impact of the legalization of cannabis for recreational use on the risk of psychosis, additional investigations through studies of better scientific quality are essential. However, based on the data already available, there is some evidence that there is a potential negative impact on mental health due to the legalization of cannabis for recreational use. In this context, in the event of legalization of cannabis for recreational use it seems essential to recommend lower risk use of cannabis (limit the frequency of use, delay the age of first consumption, control the THC content of products and promote prevention/education). Finally, in order to enable dynamic evolution of public health strategies the establishment of continued monitoring is essential as cannabis legalization evolves.

Aberrant activity at rest of the associative striatum in schizophrenia: Meta-analyses of the amplitude of low frequency fluctuations.

Schizophrenia is a severe psychiatric disorder associated with brain alterations at rest. Amplitude of low-frequency fluctuations (ALFF) and its fractional version (fALFF) have been widely used to investigate alterations in spontaneous brain activity in schizophrenia. However, results are still inconsistent. Furthermore, while these measurements are similar, they showed some differences, and no meta-analysis has been yet performed to compare them in schizophrenia. Thus, we conducted systematic research in five databases and in the grey literature to find articles investigating fALFF and/or ALFF alterations in schizophrenia. Two separate meta-analyses were performed using the SDM-PSI software to identify fALFF and ALFF alterations separately. Then, a conjunction analysis was conducted to determine congruent results between the two approaches. We found that patients with schizophrenia showed altered fALFF activity in the left insula/putamen, the right paracentral lobule and the left middle occipital gyrus compared to healthy individuals. Patients with schizophrenia exhibited ALFF alterations in the bilateral putamen, the bilateral caudate nucleus, the bilateral inferior frontal gyrus, the right precuneus, the right precentral gyrus, the left postcentral gyrus, the right posterior cingulate gyrus, compared to healthy controls. ALFF increased activity in the left putamen was higher in drug-naïve patients and was correlated with positive symptoms. The conjunction analysis revealed a spatial convergence between fALFF and ALFF studies in the left putamen. This left putamen cluster is part of the associative striatum. Its alteration in schizophrenia provides additional support to the influential aberrant salience hypothesis of psychosis.

Feuerstein Instrumental Enrichment Program for People With Schizophrenia After the First Episode of Psychosis: Protocol for an Open-Label Intervention Study.

BACKGROUND: Schizophrenia is a disorder associated with neurocognitive deficits that adversely affect daily functioning and impose an economic burden. Cognitive rehabilitation interventions, particularly during the early phases of illness, have been shown to improve cognition, functionality, and quality of life. The Feuerstein Instrumental Enrichment (FIE) program, based on the Mediated Learning Experience and the Structural Cognitive Modifiability theory, has been applied in various disorders, but its applicability in schizophrenia has not yet been clarified. OBJECTIVE: This study aims to investigate the effects of the FIE program on the functionality of patients with first-episode schizophrenia. METHODS: In total, 17 patients will be recruited for an open-label intervention consisting of twice-weekly sessions for 10 weeks. The primary outcome measure will be changes in the Goal Achievement Scale score. Maze task performance from the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) battery will serve as a secondary outcome measure. At the same time, changes in Positive and Negative Syndrome Scale scores and other MATRICS domains will be analyzed as exploratory outcomes. Assessments will be administered before and after the intervention, with a follow-up period of 6 months. RESULTS: This trial was preregistered in The Brazilian Registry of Clinical Trials (RBR-4gzhy4s). By February 2024, 11 participants were enrolled in the training. Recruitment is expected to be completed by May 2024. Data analysis will be conducted between May and September 2024. The results are expected to be published in January 2025. CONCLUSIONS: This study may establish a protocol for the FIE program that uses mediation techniques for individuals in the early stages of schizophrenia. The results will add to the knowledge about strategies to promote cognitive skills and functional impairment in daily life. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/57031.

"Food for Thought": Improving Cognition in People With Schizophrenia.

OBJECTIVE: We have known that cognitive difficulties are related to functional outcomes in schizophrenia for many years. However, we have only paid attention to potential treatments relatively recently, so implementation has been slow. METHODS: This is a narrative review describing the development of cognitive remediation treatments to improve cognitive skills and their effects on functioning. It also reviews the types of cognitive remediation with some evidence on their effects. RESULTS: Models of treatment have now been clarified and have led to a landmark paper by cognitive remediation experts around the world on the ingredients of cognitive remediation to produce the most benefit. This expert judgement on good clinical practice was justified by a large meta-analysis that supported the extra benefit of the four ingredients: an active therapist, massed practice of cognitive skills, the teaching of cognitive strategies and additional rehabilitation to transfer skills to real life. CONCLUSION: Although there is evidence of efficacy and of the beneficial therapy ingredients there is little implementation of cognitive remediation, so the establishment of cognitive remediation into mental health services needs an implementation pathway.

Do help-seeking adolescents report more psychotic-like experiences than young adults on the 16-item version of the prodromal questionnaire (PQ-16)?

AIM: To compare psychotic-like experiences (PLEs) in adolescents and young adults referred to the Mental Health Services (MHSs). METHODS: Participants scored the 16-item Prodromal Questionnaire (PQ-16) as part of the intake procedure. Data on the Diagnostic and Statistical Manual of Mental Disorders (DSM) classification and demographic data were collected. RESULTS: The PQ-16 was completed by 13 783 respondents (mean age 24.63 years, SD = 6.09; 62.6% female). Overall, the scores on the PQ-16 were not higher for adolescents (11-17 years; m = 4.84, SD = 3.62) than for young adults (18-35 years; m = 5.47, SD = 3.85). On PQ-16 item level, adolescents reported seeing and hearing things more than adults did. Across all age groups, males scored lower on the PQ-16 than females. Specifically, adolescent males scored lower than other participants. For adolescents and young adults alike, PQ-16 scores were higher for participants with borderline personality disorder, PTSD, and mood disorder than for those with other DSM classifications. CONCLUSIONS: Although help-seeking adolescents did not score higher on the PQ-16 than help-seeking young adults, more of them reported perceptual anomalies. Irrespective of age, participants with borderline personality disorder, PTSD and mood disorder scored higher on the PQ-16 than those with other DSM classifications.

Effects of Physical Activity on Disordered Eating Behaviours in Individuals With a Psychotic Disorder.

AIM: This study aims to determine the effect of physical activity on cognitive restraint, uncontrolled eating and emotional eating in individuals with a psychotic disorder. METHODS: Twenty-seven participants with a psychotic disorder (55% male; mean age: 30 ± 7.5 years; Caucasian: 66.7%; schizophrenia spectrum disorders: 44.4%; bipolar disorder with psychotic features: 29.6%) took part in a 6-month bi-weekly physical activity program (walking, running, yoga, cycling and dancing). The Three-Factor Eating Questionnaire was used to assess participant's eating behaviours, and the frequency of completed physical activity sessions was compiled. RESULTS: The mixed models analysis approach revealed that the level of cognitive restraint remained unchanged (pre: 39.2 ± 18.7 vs. post: 44.1 ± 18.3; p = 0.24), while the levels of uncontrolled eating (pre: 39.7 ± 19 vs. post: 31.6 ± 19.7; p = 0.02) and emotional eating (pre: 45.5 ± 22.3 vs. post: 32.2 ± 22.2; p < 0.001) decreased at the end of the 6-month physical activity program. DISCUSSION: This study showed that physical activity has positive effects on disordered eating behaviours in individuals with a psychotic disorder, similarly to previous studies on other populations (e.g., overweight and obese participants, postmenopausal women). CONCLUSION: Further studies are warranted to better understand the role of physical activity in moderating eating behaviours.

Neurosyphilis Presenting as Psychiatric Symptoms at Younger Age: A Case Report.

Neurosyphilis is a central nervous system infection caused by Treponema pallidum that imitates various neurological and mental disorders. Therefore, patients with this disease are prone to misdiagnoses. Here, we report a case of neurosyphilis with a psychotic disorder as the main manifestation. A young girl exhibited mental and behavioural abnormalities after a heartbreak, which manifested as alternating low mood, emotional irritability, and a lack of interest in social relations, followed by memory loss. The cerebrospinal fluid protein - Treponema pallidum particle agglutination test was positive, the toluidine red unheated serum test titre was 1:4, the white blood cell count was 5 × 10^6/L, the cerebrospinal fluid protein level was 0.97 g/L, and the brain CT was abnormal. After admission, the possibility of neurosyphilis was considered and the patient received intravenous penicillin G treatment. The patient's clinical symptom ms improved. This case emphasises that doctors should maintain clinical suspicion of Treponema pallidum infection in adolescent patients with mental abnormalities.

Societal recovery trajectories in people with a psychotic disorder in long term care: a latent class growth analysis.

PURPOSE: For many individuals with a psychotic disorder societal recovery is not accomplished. Research on societal recovery trajectories is mostly focussed on patients with a first episode psychosis. The present study aims to identify distinct societal trajectories in those with long duration of illness, through the identification of patient subgroups that are characterized by homogeneous trajectories. METHODS: Longitudinal data were used from an ongoing dynamic cohort in which people with a psychotic disorder receive yearly measurements to perform a latent class growth analysis. Societal functioning was assessed with the Functional Recovery tool, consisting of three items (1) daily living and self-care, (2) work, study and housekeeping, and (3) social contacts. Furthermore, logistic regression was used to compare subgroups with similar societal recovery at baseline, but distinct trajectories. RESULTS: A total of 1476 people were included with a mean treatment time of 19 years (SD 10.1). Five trajectories of functioning were identified, a high stable (24.5%), a medium stable (28.3%), a low stable (12.7%), a high declining (11.2%) and a medium increasing subgroup (23.3%). Predictors for not deteriorating included happiness, recent hospitalisation, being physically active, middle or higher education and fewer negative symptoms. Predictors for improving included fewer positive and negative symptoms, fewer behavioural problems and fewer physical and cognitive impairments. CONCLUSION: While the majority of individuals show a stable trajectory over four years, there were more patients achieving societal recovery than patients deteriorating. Predictors for improvement are mainly related to symptoms and behavioural problems, while predictors for deteriorating are related to non-symptomatic aspects such as physical activity, happiness and level of education.

Recurrent COVID-19-related psychotic disorder with neuro-immuno-endocrine dysfunction as a possible underlying mechanism: A case report from China.

Background: SARS-CoV-2, first identified in Wuhan, China, in December 2019, has been gradually spreading worldwide since 2020. The relationship between SARS-CoV-2 infection and psychotic disorders has received much attention, and several studies have described the direct/indirect mechanisms of its effects on the brain, but no mechanism has been found to explain recurrent episodes of COVID-19-related psychotic symptoms. Case: We report the case of an 18-year-old female patient with no family or personal psychotic disorder history with multiple hospital admissions with symptoms such as disorganized speech and behavior, hyperactivity, restlessness, and impulsive aggression during the COVID-19 recovery period. Relevant tests revealed longitudinal changes such as persistent IL-6 and IL-10 elevation, abnormal discharges on EEG, and brain and hippocampal MRI abnormal signals. The patient was treated with antipsychotics, MECT, combination therapy of hormones and antivirals, then discharged after multiple treatment rounds. Conclusion: The case presented here outlines the possibility that the COVID-19 recovery period may be a critical period for acute psychotic episodes and that the patient's recurrent psychotic symptoms may be associated with neuro-immuno-endocrine dysfunction mediated by sustained cytokine synthesis, further causing structural and functional brain damage. Routine psychiatric evaluation and related screening should be performed at all stages of the illness to better identify, prevent, and effectively intervene in psychiatric disorders following COVID-19. Because many outcomes require long-term assessment, a clearer understanding of the impact of the COVID-19 epidemic on mental health is likely to emerge in the future.

Investigation of Siblings of Patients Diagnosed with Substance-Induced Psychotic Disorder in terms of Cognitive Functions and Clinical High-Risk State for Psychosis.

OBJECTIVE: This study aimed to investigate the influence of familial predisposition on substance-induced psychosis among healthy siblings of patients diagnosed with substance-induced psychotic disorder, who themselves lack any family history of psychotic disorders. Additionally, the study aimed to explore clinical high-risk states for psychosis, schizotypal features, and neurocognitive functions in comparison to a healthy control group. METHOD: The study compared healthy siblings of 41 patients diagnosed with substance-induced psychotic disorder with 41 healthy volunteers without a family history of psychotic disorders, matching age, gender, and education. Sociodemographic and clinical characteristics of participants were obtained using data collection forms. The Comprehensive Assessment of At-Risk Mental States (CAARMS) and the Structured Interview for Schizotypy-Revised Form (SIS-R) scales were utilized to assess clinical high risk for psychosis. Neurocognitive functions were evaluated with digit span test (DST), trail making test part A-B (TMT), verbal fluency test (VFT), and Stroop test (ST). RESULTS: Analysis using the CAARMS scale revealed that 39% of siblings and 7.3% of the control group were at clinically high risk for psychosis, indicating a significant difference in rates of psychotic vulnerability. Comparison between siblings and the control group showed significant differences in mean SIS-R subscale scores, including social behavior, hypersensitivity, referential thinking, suspiciousness, illusions, and overall oddness, as well as in mean neurocognitive function scores, including errors in TMT-A, TMT-B, and VFT out-of-category errors, with siblings exhibiting poorer performance. CONCLUSION: Our study suggests that healthy siblings of patients with substance-induced psychosis exhibit more schizotypal features and have a higher risk of developing psychosis compared to healthy controls. Additionally, siblings demonstrate greater impairment in attention, response inhibition, and executive functions compared to healthy controls, indicating the potential role of genetic predisposition in the development of substance-induced psychotic disorder.

The relationship between schizophrenia or schizoaffective disorder and type 1 diabetes mellitus: a scoping review of observational studies.

OBJECTIVE: Both schizophrenia and type 1 diabetes mellitus (T1D) are known as immune-related disorders. We systematically reviewed observational studies to explore the relationship between schizophrenia or schizoaffective disorder and T1D. METHODS: A preliminary search of articles was completed using the following databases: Airiti Library, CINAHL Complete (via EBSCOhost), OVID MEDLINE, Embase, and PubMed. Two researchers independently assessed each study's quality based on Joanna Briggs Institute (JBI). A narrative review summarized the potential relationship between the two diseases. RESULTS: Eleven studies were included in the final analysis. Six observational studies investigated the risk of schizophrenia and schizoaffective disorder in patients with T1D. Two studies showed negative correlations, one showed no correlation, and three showed positive correlations. On the other hand, five studies reported the prevalence of T1D in patients with schizophrenia. Two of them showed positive associations, and three others showed no association. Although the majority of the included studies suggested a positive association between the two medical conditions, these studies were still too heterogeneous to draw consistent results. CONCLUSION: We found conflicting results regarding the bidirectional relationship between schizophrenia or schizoaffective disorder and T1D. These may stem from differences in study design, sampling methods, or definition of diagnoses, which are essential aspects to consider in future research.