Clinical and molecular characteristics of 26 fetuses with lethal multiple congenital contractures.

Multiple congenital contractures (MCC) due to fetal akinesia manifest across a broad spectrum of diseases, ranging from mild distal arthrogryposis to lethal fetal akinesia deformation sequence. We hereby present a series of 26 fetuses displaying severe MCC phenotypes from 18 families and describe detailed prenatal ultrasound findings, postmortem clinical evaluations, and genetic investigations. Most common prenatal findings were abnormal facial profile (65%), central nervous system abnormalities (62%), polyhydramnios (50%), increased nuchal translucency (50%), and fetal hydrops (35%). Postmortem examinations unveiled additional anomalies including facial dysmorphisms, dysplastic skeletal changes, ichthyosis, multiple pterygia, and myopathy, allowing preliminary diagnosis of particular Mendelian disorders in multiple patients. Evaluation of the parents revealed maternal grip myotonia in one family. By exome sequencing and targeted testing, we identified causative variants in ACTC1, CHST14, COG6, DMPK, DOK7, HSPG2, KLHL7, KLHL40, KIAA1109, NEB, PSAT1, RAPSN, USP14, and WASHC5 in 15 families, and one patient with a plausible diagnosis associated with biallelic NEB variants. Three patients received a dual diagnosis. Pathogenic alterations in newly discovered genes or in previously known genes recently linked to new MCC phenotypes were observed in 44% of the cohort. Our results provide new insights into the clinical and molecular landscape of lethal MCC phenotypes.

Dysregulation of Plasma Growth Factors and Chemokines in Cocaine Use Disorder: Implications for Dual Diagnosis with Schizophrenia and Antisocial Personality Disorder in an Exploratory Study.

INTRODUCTION: Dual diagnosis in individuals with cocaine use disorders (CUDs) presents a mental health challenge marked by an increased susceptibility to disabling morbidities and premature mortality. Despite extensive research on depression and anxiety, other prevalent comorbidities, such as psychotic and personality disorders, have received less attention. This study explores inflammation-related mediators as potential biomarkers for CUD and dual diagnosis with schizophrenia (SCZ) or antisocial personality disorder (APD). METHODS: This exploratory study included 95 participants, comprising 40 healthy subjects and 55 abstinent patients with CUD. Lifetime CUD was diagnosed either as single diagnosis (CUD group, N = 25) or as a dual diagnosis (DD group. N = 30) with SCZ (CUD+SCZ subgroup) or APD (CUD+APD subgroup). Participants were clinically assessed, and the plasma concentrations of growth factors (i.e., G-CSF, BDNF, and VEGF-A) and chemokines (i.e., CCL11/eotaxin-1, CCL2/MCP-1, and CXCL12/SDF-1) were determined and log(10)-transformed for analysis. RESULTS: Growth factors and chemokines were dysregulated by CUD and psychiatric diagnoses. Specifically, patients in the CUD group exhibited significantly lower concentrations of G-CSF and CCL11/eotaxin-1 than the control group. In contrast, the DD group showed significantly higher concentrations of all analytes than both the CUD and control groups. Additionally, no differences in these analytes were observed between the CUD+SCZ and CUD+APD subgroups within the DD group. Regarding cocaine-related variables, significant associations were identified in the CUD group: an inverse correlation between the age at first cocaine use and the concentrations of BDNF and CCL2/MCP-1; and a positive correlation between the duration of the cocaine abstinence and the concentrations of BDNF and CCL11/eotaxin-1. Lastly, a logistic regression model incorporating all these analytes demonstrated high discriminatory power in distinguishing patients with CUD alone from those with dual diagnosis. CONCLUSIONS: Individuals with dual diagnosis of CUD exhibit elevated concentrations of growth factors and chemokines, distinguishing them from those with CUD alone. It is unclear whether the differences in these inflammatory mediators are specific to the presence of SCZ and APD. The study highlights potential biomarkers and associations, providing valuable insights into the intricate interplay of CUD and psychiatric disorders to enhance clinical diagnosis and therapeutics.

Destination Matters More: Relapse following Hospital-Based Treatment of Substance Use Disorders With and Without Co-Occurring Disorders.

OBJECTIVES: Addressing substance use in psychiatric care encounters significant barriers, but the emergence of specialized services offers an opportunity to advance and scale up the integration of addiction services within psychiatric settings. However, research gaps still exist in this field, particularly in understanding the substance relapse rates of people with co-occurring disorders after a psychiatric hospitalization. This study aimed to investigate and compare the relapse rates of patients under inpatient care with exclusively addiction-related issues and those with co-occurring disorders after a hospitalization in a psychiatric ward and gain insights into differences in outcomes for these two patient groups. METHODS: This retrospective analysis examined electronic medical records of patients admitted to the Acute Psychiatry Ward of the Hospital Clinic of Barcelona with a substance use disorder diagnosis between January 2019 and February 2021. Cox regression was used to identify variables independently associated with the first relapse episode. RESULTS: From a total of 318 admissions (79.2% with psychiatric comorbidity), 76.1% relapsed during the study follow-up, with a median survival time of 54 days. Younger age, female gender, voluntary admission, and outpatient follow-up were independently associated with relapse. The presence of a co-occurring disorder was not associated with relapse. CONCLUSION: This study highlights the need for interventions aimed at improving post-discharge abstinence rates for addiction-related hospitalizations. It also challenges the notion that co-occurring disorders automatically imply a worsened prognosis and emphasizes the importance of addressing addiction and psychiatric comorbidity in a comprehensive, integrated, and specialized manner.

Examining Profiles and Treatment Outcomes in Dual Diagnosis: Comparison of Coordinated Treatment With Mental Health Services Versus Addiction Center Alone. A Real-World Data Analysis.

OBJECTIVE: The aim of this work was to examine the profile and treatment outcomes of patients with dual pathology depending on whether the patients were attending addiction centers or are being treated in a coordinated model by mental health services. METHODS: Data from 7225 dual diagnosis patients were used, of whom 2417 (33.5%) received treatment in the mental health coordinated modality. Clinical information was taken from the patients' electronic health record. RESULTS: Differences were found in patients' sociodemographic and comorbidity profiles according to treatment modality. In general, coordinated care yielded favorable outcomes (higher attendance and lower dropout rates but no differences in retention). The logistic regression analysis identified predictors of patient profiles in coordinated care, emphasizing having a severe mental health disorder (OR = 3.878, 95% CI [3.443, 4.368]; p = .000), being referred by social/health services, or having retired status. Main differences were observed according to the comorbid diagnosis presented, particularly in cases in which the patient had impulse control, hyperkinetic, or cluster C personality disorder. CONCLUSIONS: While therapeutic outcomes are influenced by associated comorbidities, the disorders prognosis can be favorable with appropriate treatment. Furthermore, analysis of differences according to treatment modality allows for predicting the type of patient who will receive a particular service, which enables the development of tailored treatments.

Which Factors Are Associated With Comorbid Psychiatric Conditions in Patients Affected by Substance Use Disorders? The Impact of COVID-19 Pandemic on Dual-Diagnosis Subjects.

OBJECTIVE: To investigate demographic/cinical variables associated to dual diagnosis and the psychological reaction of dual-diagnosis patients to COVID-19 pandemic. METHODS: Information was collected at the Addiction Service of Monza, Italy. The Impact of Event Scale-Revised (IES-R), a self-report questionnaire measuring the subjective response to a traumatic event, was administered. Univariate analyses and binary logistic regression were performed. IES-R scores were compared between groups defined by qualitative variables through one-way analyses of variance (ANOVA). RESULTS: 118 outpatients were included, 48.3% with dual diagnosis. Alcohol use disorder and being female were associated to dual diagnosis. IES-R scores were significantly higher in the dual-diagnosis group, especially for personality disorders (PDs). IES-R scores were higher in patients taking treatment for substance use disorder (SUD). CONCLUSIONS: Females and alcohol abusers were at-risk subjects for dual diagnosis. Patients with SUD and PDs may benefit from additional support, especially when traumatic life events occur. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04694482.

Characterization of substance use in homeless patients with mental disorders.

BACKGROUND: In Denmark, 42% of homeless people suffer from dual diagnosis, i.e. the co-occurrence of a substance use of alcohol and/or illegal substances and another psychiatric disorder. Dual diagnosis homeless patients often cause differential diagnostic difficulties and fail to receive effective treatment. A solid grasp of the role of substance use in these patients may inform the diagnostic decision and contribute to improve their treatment. Today, knowledge of these issues remains scarce. The purpose of this study was to explore substance use in homeless patients with mental disorders and their subjective perspectives on their substance use. METHODS: 44 homeless dual diagnosis patients were included in the study. They were examined in interviews focusing on their substance use and their subjective perspective on their substance use. RESULTS: The most frequently used substances were cannabinoids (70.5%) and alcohol (45.5%), followed by cocaine, sedative/hypnotics, and amphetamine. The finding suggests that substance use in dual diagnosis homeless patients is a complex phenomenon with most patients (56.8%) using multiple substances. While substance use seems to contribute to keep the patients homeless, substance use was also reported to play an important role in coping with life on the streets by offering social contact and some relief from a desperate situation. CONCLUSION: Substance use, mental disorder, and homelessness seem to be closely entangled, reinforcing each other and making it difficult to help these vulnerable patients. Diagnostic overshadowing may cause delays in adequate diagnosis and treatment of this group of patients.

Perceived advantages and disadvantages of substance use in a dual diagnosis population with severe mental disorders and severe substance use disorder. Considering the self-medication hypothesis.

AIM: Based on a large cohort of dual diagnosis patients, the aim of this study was to quantify the patient-perceived problems and advantages of their substance use and relate the quantity of problems to the substance type and psychiatric diagnosis. MATERIAL: Data comes from a naturalistic cohort admitted to an in-patient facility in Denmark specialized in integrated dual diagnosis treatment. We included 1076 patients at their first admission to the facility from 2010 to 2017. Participants completed 607 DrugCheck and 130 DUDIT-E questionnaires. METHOD: we analyzed the questionnaires and included admission diagnosis by use of t-test and ANOVA to depict the patterns in substance use in relation to psychiatric diagnosis. RESULTS: The three most common substance related problems according to the DrugCheck questionnaire were: feeling depressed, financial problems, and losing interest in daily activities. From DUDIT-E, the highest-ranking negative substance related effects were financial ruin, deterioration of health, and problems at work. Effects on social life relationships were also evident with more than 40% of participants. The top three positive substance related effects reported were relaxation, improved sleep, and control over negative emotions. The number of problems listed varied significantly with the type of preferred substance. Patients using pain medication, sedatives, central stimulants, and alcohol reported most problems. Diagnosis did not differentiate the problems experienced. Results partially support the broad self-medication hypothesis for patients with severe mental illness, but also points out that patients are well aware of negative effects.

"And Now that I Feel Safe I'm Coming Out of Fight or Flight": A Qualitative Exploration of Challenges and Opportunities for Residents' Mental Health in Substance Use Recovery Housing.

Co-occurring mental health concerns are prevalent among substance use recovery housing residents. We sought to explore how residents with co-occurring mental health and substance use needs experience recovery housing. We conducted semi-structured interviews with residents (N = 92) in recovery homes across Texas and developed themes through thematic analysis. Residents note that living in a group home can exacerbate anxiety and paranoia, especially during periods of high turnover. Overwhelmingly, however, residents believe recovery housing improves their mental health. Residents use their shared lived experiences to support one another. Residents also express appreciation for the transition period offered by recovery housing, allowing them to solidify their recoveries before fully re-entering society. Participants describe recovery homes as a critical support for their co-occurring mental health and substance use concerns. These results provide key insights on how to better support mental health in recovery housing.

Depressive and Anxiety Symptoms Predict Obsessive and Compulsive Cravings among Depressed Alcoholics.

Objectives: Alcohol craving is often associated with mood symptoms and predicts alcohol use in individuals with alcohol dependence. However, little is known about the impact of mood symptoms on alcohol craving in comorbid mood disorders and alcohol dependence. This study examines the predictive value of depressive and anxiety symptoms for obsessive and compulsive aspects of alcohol craving in adults with comorbid Major Depressive Disorder (MDD) and Alcohol Dependence. Methods: Fifty-five adults (47% female; mean age of 39.35 (SD=8.80)) with DSM-IV diagnoses of comorbid MDD and alcohol dependence were prospectively assessed over a six-month period. They completed the Hamilton Rating Scales for Depression and Anxiety, the Alcohol Timeline Followback, the Obsessive Compulsive Drinking Scale (OCDS), the Alcohol Dependence Scale (ADS), and the Addiction Severity Index (ASI). The linear mixed model analyses for repeated measures was used to test weather depressive and anxiety symptoms predict OCDS subscale scores. Results: Depressive and anxiety symptoms were strongly associated with obsessive and compulsive subscales of the OCDS. Baseline ASI-alcohol scores were associated with both the obsessive and compulsive and with the obsessive subscale scores in the predictive model including depressive symptoms, and that including anxiety symptoms respectively. Conclusions: Results suggest that depressive and anxiety symptoms predict obsessive and compulsive aspects of alcohol craving in adults with comorbid MDD and alcohol dependence. Assessing the severity of depressive and anxiety symptoms and alcohol use in this population may identify those more likely to experience intense alcohol craving states and at increased risk of relapse.

A narrative systematic review of associations and temporality between use of methamphetamine, ecstasy/MDMA, or cocaine with anxiety or depressive symptoms.

OBJECTIVE: Anxiety and depression are prevalent mental health problems in people who use illicit stimulants. Improved understanding of the temporal relationship between methamphetamine, ecstasy/MDMA, or cocaine use with anxiety or depression informs public health interventions and treatment options for those experiencing this co-occurrence. This narrative systematic review sought to examine associations and temporality between the use of methamphetamine, ecstasy/MDMA, or cocaine, with anxiety or depressive symptoms. Method Systematic searches of 4 electronic databases were conducted up to August 2023. Study eligibility included the measurement of anxiety and/or depressive symptoms, and frequency of illicit stimulant use (methamphetamine, cocaine, or ecstasy/MDMA) at two separate time points, with data analysis of the association between these variables. The Joanna Briggs Critical Appraisal Checklist was utilised to assess quality. Data was extracted, and a narrative synthesis incorporating an eight-criteria framework to assess associations was conducted. Results 4432 studies were screened for eligibility; 11 studies (3 RCTs and 8 prospective cohort studies) were included. Evidence for an association between depressive symptoms and methamphetamine use was demonstrated in six studies, with temporal evidence in three studies supporting methamphetamine use preceding depressive symptoms. Three studies reported an association between cocaine use and depressive symptoms. Evidence for associations with any of the illicit stimulants and anxiety symptoms was lacking. CONCLUSIONS: There was some evidence to support a case for temporality, particularly for methamphetamine use and depressive symptoms. Investing in longitudinal studies is pivotal to understanding the dynamic and reciprocal relationship between illicit stimulant use and anxiety or depressive symptoms. A limitation of the study was the variation in the measurement and analysis of outcomes.

Analysis of the Relationship between Psychiatric and Addiction-Related Disorders in Patients of an Outpatient Addiction Treatment Clinic for Children and Adolescents.

INTRODUCTION: Dual diagnosis is used in addiction medicine to refer to the co-occurrence of an addiction-related disorder and another psychiatric disorder in the same individual. Adolescence is a key period for the development of both mental disorders and addictions. OBJECTIVE: The aim of this study is to describe the relationships between psychiatric and addiction-related disorders in patients of the Outpatient Addiction Treatment Clinic for Children and Adolescents at the 1st Faculty of Medicine, Charles University in Prague in 2015-2022. METHODS: Data were retrospectively analyzed from the hospital's medical system, which collects basic diagnostic data on patients. Descriptive statistics and cluster analysis were performed to identify relationships between psychiatric and addiction-related disorders. RESULTS: Of the 450 patients, 153 patients (34%) met the criteria for dual diagnosis. The most common addiction-related disorders were mental and behavioural disorders due to the use of cannabinoids (35%) and internet gaming disorder (35%). The most common psychiatric diagnoses were behavioural and emotional disorders with usual onset in childhood and adolescence (64%), with a lower prevalence in girls than in boys. CONCLUSIONS: These findings may be important for the diagnosis and treatment of risky behaviours and addictions in children and adolescents.

The association between PTSD symptom clusters and religion/spirituality with alcohol use among first responders.

Alcohol misuse and posttraumatic stress disorder (PTSD) co-occur at high rates among first responders (e.g., law enforcement, firefighters, paramedics), underscoring the need to better understand these relations to inform intervention efforts. Identifying malleable processes relevant to the association between PTSD and alcohol among first responders could inform tailored interventions. An example of such a malleable process is spirituality. As such, the current study examined the unique relationships between PTSD symptom clusters and alcohol misuse, while also accounting for the role of select demographics and religion/spirituality, in a sample of first responders. A national online sample of first responders (N = 320) completed measures of PTSD symptomology, alcohol misuse, religion/spirituality and demographics. Hierarchical linear regression analyses revealed that PTSD Intrusion (Cluster B) symptom severity was associated with greater alcohol misuse and PTSD Avoidance (Cluster C) was associated with lower alcohol misuse. Additionally, positive and negative spiritual coping were also associated with alcohol misuse. In the context of similar research among military samples, findings suggest potentially unique associations between PTSD symptom clusters and alcohol misuse among first responders. Additionally, findings highlight the potentially protective role of religion/spirituality in this population. Future research should explore nuanced relationships between PTSD symptom clusters and alcohol misuse as well as the salience of spirituality/religion in this unique population.

Diagnostic Overshadowing of Psychological Disorders in People With Intellectual Disability: A Systematic Review.

Diagnostic overshadowing is a bias in which symptoms of a psychological disorder are falsely attributed to a known diagnosis of intellectual disability. This systematic review evaluated all research on diagnostic overshadowing conducted to date, including dissertations and peer-reviewed journal articles. In total, 25 studies were included in this review. Findings suggest diagnostic overshadowing may not be as ubiquitous as originally believed, with one third of included studies finding no overshadowing. The quality of the evidence was graded as "Low" using the LEGEND tool, with common issues including outdated studies, analogue methodologies, small sample sizes and convenience samples, and inappropriate conducting or reporting of statistical analyses. Implications for the field and recommendations for future research are discussed.

Repetitive Behaviors in Autism and Obsessive-Compulsive Disorder: A Systematic Review.

PURPOSE: Obsessive-compulsive disorder (OCD) and autism are characterized by the presence of repetitive behaviors. Differentiating between repetitive behaviors attributable to a diagnosis of autism, and those attributable to OCD, poses challenges for differential and co-occurring diagnosis. Differentiation is important to inform appropriate supports and interventions for phenotypically similar but functionally distinct behaviors. In this systematic review, the quantitative literature was examined to explore the similarities and differences in repetitive behaviors (including restricted and repetitive behaviors and interests, and obsessive-compulsive behaviors) in autistic individuals and those with OCD, and those with co-occurring diagnoses, in terms of: (1) expression, (2) content, and (3) associated factors. METHODS: Thirty-one studies were identified that compared repetitive behaviors in autistic individuals, individuals with OCD, or individuals with both diagnoses. RESULTS: The results suggest considerable overlap in the intensity and content of repetitive behaviors between groups. The findings of this review highlight that research aimed specifically at understanding similarities and differences in repetitive behaviors between autistic individuals and individuals with OCD is limited and frequently only compare at total score or composite measure levels. CONCLUSION: Further research into differences in the presentation of repetitive behaviors at a subscale and item level is required to inform clearer differentiation of specific behaviors in autism versus OCD. Understanding and more accurately differentiating is essential for efficient diagnosis, effective treatment, and better outcomes.

Navigating the Complex Intersection of Substance Use and Psychiatric Disorders: A Comprehensive Review.

The co-occurrence of substance use disorders (SUDs) and psychiatric conditions, often referred to as comorbidity or concurrent disorders, presents intricate challenges in both diagnosis and treatment. This comprehensive narrative review aims to synthesize and critically evaluate the existing evidence surrounding the management of individuals with comorbid SUDs and psychiatric disorders. Comorbidity in these domains carries profound implications for clinical practice, research, and policymaking, emphasizing the need for a holistic understanding of the intricate dynamics that arise when these conditions coexist. This review explores recent research findings, evidence-based guidelines, and emerging trends within the field, offering valuable insights for clinicians, researchers, and policymakers seeking to navigate the complex terrain of comorbidity in substance use and psychiatric disorders.

Illness-related outcomes of illicit substance use disorder in adolescents with early onset schizophrenia: a multicenter study.

OBJECTIVES: Lifetime co-occurring substance use disorders are common at the time of presentation for the treatment of primary psychosis. Our aim was to investigate the clinical characteristics of adolescents with early-onset schizophrenia/schizoaffective disorder (EOS), categorized as either with (EOS + SUD) or without SUD (non-SUD/EOS), in a multi-center sample. METHODS: Between 2016 and 2022, 255 patients were evaluated across three tertiary-care inpatient units. Diagnoses were confirmed by the treating physician according to the DSM-5 during the hospital stay. The severity of symptoms was measured using the Positive and Negative Syndrome Scale (PANSS). RESULTS: The EOS + SUD group exhibited a higher illness onset, fewer years of education, longer duration of untreated psychosis (DUP), a higher frequency of male gender, more frequent hospitalizations, increased use of clozapine and zuclopenthixol LAI, along with higher rates of post-traumatic stress disorder and conduct disorder. Notably, differences in DUP, clozapine use, and the number of hospitalizations did not persist in the multivariate logistic regression model. CONCLUSIONS: Our findings support the notion of SUD playing a role in modifying the course of illness in EOS. Future studies should emphasize exploring treatment responses to medications and interventions among youth with dual diagnoses.

Pragmatic competence in people with dual diagnosis: down syndrome and autism spectrum disorder.

BACKGROUND: Pragmatics is an area that can be affected in a wide variety of disorders. In this sense, Syndromic Autism is defined as a disorder in which a causal link is established between an associated syndrome and Autism Spectrum Disorder (ASD). Likewise, Down Syndrome (DS) is one of the main genetically based syndromes in which ASD is described as one of its possible manifestations. In this direction, people with DS are described as social beings whereas in ASD there seems to be a specific alteration of this domain. METHODS: In this study, pragmatic performance was analysed in a sample of 72 participants, where comparisons were made between the scores obtained by children with ASD (n = 24), with DS (n = 24) and with DS + ASD (n = 24). RESULTS: The Social Communication Questionnaire (SCQ), the Block Objective and Criterial Language Battery (BLOC-SR) and the Neuropsychology subtest (NEPSY-II) aimed at Theory of Mind (ToM) identified significant differences between the groups. However, two-to-two comparisons reported no significant differences between DS and DS + ASD. CONCLUSIONS: Although several studies report differences between the three proposed groups, our data seem to suggest that ASD symptomatology in DS is associated with Intellectual Developmental Disorder (IDD). However, the lack of solid scientific evidence regarding comorbid diagnosis makes further research along these lines indispensable. TRIAL REGISTRATION: This study was approved by the Ethics Committee for Social Research at UCLM with reference CEIS-704,511-L8M4.

Workforce Perspectives of Sustaining the Utilisation of a Harm Reduction Instrument in a Mental Health Residential Setting.

PURPOSE: This exploratory study investigated worker experiences of utilising the Before During After (BDA) harm reduction instrument to engage well with service users in a residential mental health service setting. Stakeholder interviews were conducted with a purposive sample of two senior nurses and one senior allied health staff at the study site to explore the impacts of BDA implementation on their work after 3 years of its use. A thematic analysis was conducted, including two-level coding. Five major themes were discussed. Of particular interest, and the focus of this paper, are the themes of effect on service users and effect on staff. The study found improved engagement between staff and service users, reduced stigma and more holistic care that was collaborative. In regard to staff, it was found that staff knowledge and confidence increased in addressing harm reduction issues with consumers and this was sustained over 3 years. Use of the BDA clinical instrument and package was reported to enhance worker engagement, knowledge and confidence in dual diagnosis work with service users.

Exploring dual diagnosis in opioid agonist treatment patients: a registry-linkage study in Czechia and Norway.

BACKGROUND: Knowledge of co-occurring mental disorders (termed 'dual diagnosis') among patients receiving opioid agonist treatment (OAT) is scarce. This study aimed (1) to estimate the prevalence and structure of dual diagnoses in two national cohorts of OAT patients and (2) to compare mental disorders between OAT patients and the general populations stratified on sex and standardized by age. METHODS: A registry-linkage study of OAT patients from Czechia (N = 4,280) and Norway (N = 11,389) during 2010-2019 was conducted. Data on mental disorders (F00-F99; ICD-10) recorded in nationwide health registers were linked to the individuals registered in OAT. Dual diagnoses were defined as any mental disorder excluding substance use disorders (SUDs, F10-F19; ICD-10). Sex-specific age-standardized morbidity ratios (SMR) were calculated for 2019 to compare OAT patients and the general populations. RESULTS: The prevalence of dual diagnosis was 57.3% for Czechia and 78.3% for Norway. In Czechia, anxiety (31.1%) and personality disorders (25.7%) were the most prevalent, whereas anxiety (33.8%) and depression (20.8%) were the most prevalent in Norway. Large country-specific variations were observed, e.g., in ADHD (0.5% in Czechia, 15.8% in Norway), implying differences in screening and diagnostic practices. The SMR estimates for any mental disorders were 3.1 (females) and 5.1 (males) in Czechia and 5.6 (females) and 8.2 (males) in Norway. OAT females had a significantly higher prevalence of co-occurring mental disorders, whereas SMRs were higher in OAT males. In addition to opioid use disorder (OUD), other substance use disorders (SUDs) were frequently recorded in both countries. CONCLUSIONS: Results indicate an excess of mental health problems in OAT patients compared to the general population of the same sex and age in both countries, requiring appropriate clinical attention. Country-specific differences may stem from variations in diagnostics and care, reporting to registers, OAT provision, or substance use patterns.