Polygenic Risk of Mental Disorders and Subject-Specific School Grades

BACKGROUND

Education is essential for socioeconomic security and long-term mental health; however, mental disorders are often detrimental to the educational trajectory. Genetic correlations between mental disorders and educational attainment do not always align with corresponding phenotypic associations, implying heterogeneity in the genetic overlap.

METHODS

We unraveled this heterogeneity by investigating associations between polygenic risk scores for 6 mental disorders and fine-grained school outcomes: school grades in language and mathematics in ninth grade and high school, as well as educational attainment by age 25, using nationwide-representative data from established cohorts (N = 79,489).

RESULTS

High polygenic liability of attention-deficit/hyperactivity disorder was associated with lower grades in language and mathematics, whereas high polygenic risk of anorexia nervosa or bipolar disorder was associated with higher grades in language and mathematics. Associations between polygenic risk and school grades were mixed for schizophrenia and major depressive disorder and neutral for autism spectrum disorder.

CONCLUSIONS

Polygenic risk scores for mental disorders are differentially associated with language and mathematics school grades.

Revisiting the association between treatment with antidepressants and mania: A nationwide within-individual study of 3554 patients with bipolar disorder

INTRODUCTION

Antidepressants are commonly used "off-label" for bipolar depression, despite concerns over the risk of potential treatment-emergent mania (or "manic switch"). Treatment-emergent mania is difficult to study with adequate power in clinical trials as it requires a large group of participants and long follow-up. Therefore, naturalistic register-based studies have been applied to assess this phenomenon. Here, we aimed to replicate previous findings and address key methodological limitations that were not previously taken into account.

METHODS

We utilized data from nationwide Danish health registries to identify patients with bipolar disorder treated with an antidepressant, either with or without concomitant treatment with a mood stabilizer (drug treatment proxied via redeemed prescriptions). We plotted the incidence of manic and depressive episodes relative to the initiation of antidepressant treatment and compared the incidence of mania in the period prior to and following initiation of antidepressant treatment (within-individual design).

RESULTS

In 3554 patients with bipolar disorder initiating treatment with an antidepressant, the number of manic episodes peaked approximately 3 months prior to initiation of antidepressant treatment, and the number of depressive episodes peaked around the initiation of antidepressant prescription. This temporal pattern suggests that antidepressants were used to treat post-manic depression.

CONCLUSION

Within-individual designs do not control sufficiently for confounding by indication, when the treatment indication is time-varying. Thus, results from prior within-individual studies of antidepressant treatment in the context of bipolar disorder may be invalid due to time-varying confounding by indication.

Cannabis Use Disorder and Subsequent Risk of Psychotic and Nonpsychotic Unipolar Depression and Bipolar Disorder

Importance

Cannabis use is increasing worldwide and is suspected to be associated with increased risk of psychiatric disorders; however, the association with affective disorders has been insufficiently studied.

Objective

To examine whether cannabis use disorder (CUD) is associated with an increased risk of psychotic and nonpsychotic unipolar depression and bipolar disorder and to compare associations of CUD with psychotic and nonpsychotic subtypes of these diagnoses.

Design, Setting, and Participants

This prospective, population-based cohort study using Danish nationwide registers included all individuals born in Denmark before December 31, 2005, who were alive, aged at least 16 years, and living in Denmark between January 1, 1995, and December 31, 2021.

Exposure

Register-based diagnosis of CUD.

Main Outcome and Measures

The main outcome was register-based diagnosis of psychotic or nonpsychotic unipolar depression or bipolar disorder. Associations between CUD and subsequent affective disorders were estimated as hazard ratios (HRs) using Cox proportional hazards regression with time-varying information on CUD, adjusting for sex; alcohol use disorder; substance use disorder; having been born in Denmark; calendar year; parental educational level (highest attained); parental cannabis, alcohol, or substance use disorders; and parental affective disorders.

Results

A total of 6 651 765 individuals (50.3% female) were followed up for 119 526 786 person-years. Cannabis use disorder was associated with an increased risk of unipolar depression (HR, 1.84; 95% CI, 1.78-1.90), psychotic unipolar depression (HR, 1.97; 95% CI, 1.73-2.25), and nonpsychotic unipolar depression (HR, 1.83; 95% CI, 1.77-1.89). Cannabis use was associated with an increased risk of bipolar disorder in men (HR, 2.96; 95% CI, 2.73-3.21) and women (HR, 2.54; 95% CI, 2.31-2.80), psychotic bipolar disorder (HR, 4.05; 95% CI, 3.52-4.65), and nonpsychotic bipolar disorder in men (HR, 2.96; 95% CI, 2.73-3.21) and women (HR, 2.60; 95% CI, 2.36-2.85). Cannabis use disorder was associated with higher risk for psychotic than nonpsychotic subtypes of bipolar disorder (relative HR, 1.48; 95% CI, 1.21-1.81) but not unipolar depression (relative HR, 1.08; 95% CI, 0.92-1.27).

Conclusions and Relevance

This population-based cohort study found that CUD was associated with an increased risk of psychotic and nonpsychotic bipolar disorder and unipolar depression. These findings may inform policies regarding the legal status and control of cannabis use.

The clinical use of electroencephalography in a general psychiatric setting

OBJECTIVE

Electroencephalography (EEG) is used in psychiatric services, however, clinical guidelines do not clearly state when EEG is indicated, and its diagnostic value in psychiatric settings is unclear. We aimed to characterize the clinical use and diagnostic consequences of EEG in a general psychiatric setting to evaluate and optimize its use.

METHODS

We performed a quality development project at the psychiatric services of the Central Denmark Region. We identified patients referred for EEG examination from psychiatric services between 1 September 2017 and 1 September 2022. We extracted data from electronic health records on patient characteristics, indications, EEG results, and treatment consequences and analyzed risk factors for abnormal EEGs.

RESULTS

Among 57,031 persons seen in the psychiatric services in the study period, 219 (0.4%) were referred for EEG examination. Psychosis (n = 70, 32%) was the most common symptom and suspicion of epilepsy (n = 129, 59%) was the most common clinical suspicion leading to referral. Of the 219 patients, 53 (24%) had an abnormal EEG result including 17 (7.8%) with epileptiform changes. Abnormal EEGs led to treatment alterations in six patients (3%). Age, prior epilepsy, use of antiseizure medication, use of clozapine, and convulsions were associated with epileptiform changes in the EEG.

CONCLUSION

EEG is rarely used in psychiatric settings and seldom has treatment consequences. However, in specific clinical settings, the EEG result leads to an alteration of clinical management and the findings, therefore, call for refinement of clinical guidelines to optimize the use of EEG.

Genetic assortative mating for schizophrenia and bipolar disorder

BACKGROUND

Psychiatric disorders are highly polygenic and show patterns of partner resemblance. Partner resemblance has direct population-level genetic implications if it is caused by assortative mating, but not if it is caused by convergence or social homogamy. Using genetics may help distinguish these different mechanisms. Here, we investigated whether partner resemblance for schizophrenia and bipolar disorder is influenced by assortative mating using polygenic risk scores (PRSs).

METHODS

PRSs from The Danish High-Risk and Resilience Study-VIA 7 were compared between parents in three subsamples: population-based control parent pairs (N=198), parent pairs where at least one parent had schizophrenia (N=193), and parent pairs where at least one parent had bipolar disorder (N=115).

RESULTS

The PRS for schizophrenia was predictive of schizophrenia in the full sample and showed a significant correlation between parent pairs (r=0.121, p=0.0440), indicative of assortative mating. The PRS for bipolar disorder was also correlated between parent pairs (r=0.162, p=0.0067), but it was not predictive of bipolar disorder in the full sample, limiting the interpretation.

CONCLUSIONS

Our study provides genetic evidence for assortative mating for schizophrenia, with important implications for our understanding of the genetics of schizophrenia.

Mental health of patients with mental illness during the COVID-19 pandemic lockdown: a questionnaire-based survey weighted for attrition

BACKGROUND

Individuals with pre-existing mental illness may be particularly vulnerable to the negative impact that the coronavirus disease 2019 (COVID-19) pandemic seems to have on mental health. Accordingly, the objective of the present study was to assess whether patients with mental illness experienced deterioration in mental health during the COVID-19 lockdown of Denmark in the Spring of 2020.

METHODS

We conducted a cross-sectional, questionnaire-based survey coupled with sociodemographic and clinical data from the medical records of all invitees. The latter enabled analysis of attrition and weighting of results. The online questionnaire included the 18-item Brief Symptom Inventory (BSI-18), the five-item World Health Organization Well-Being Index (WHO-5), and 14 questions evaluating worsening or improvement in symptoms during lockdown using the pre-pandemic period as reference.

RESULTS

A total of 992 randomly drawn patients with mental illness from the psychiatric services of the Central Denmark Region responded to the questionnaire (response rate = 21.6%). The weighted mean WHO-5 and BSI-18 scores were 38 and 28, respectively. A total of 52% of the respondents reported that their mental health had deteriorated during the lockdown, while 33% reported no change, and 16% reported improvement. The most commonly reported reasons for deterioration were loneliness, disruption of routines, concerns regarding the coronavirus, less contact with family/friends, boredom, and reduced access to psychiatric care.

CONCLUSION

More than half of the patients reported worsening of their mental health during the pandemic lockdown. There should be an increased emphasis on ensuring both social and clinical support for individuals with mental illness during pandemics.

The Danish High-Risk and Resilience Study-VIA 15 - A Study Protocol for the Third Clinical Assessment of a Cohort of 522 Children Born to Parents Diagnosed With Schizophrenia or Bipolar Disorder and Population-Based Controls

BACKGROUND

Children born to parents with severe mental illness have gained more attention during the last decades because of increasing evidence documenting that these children constitute a population with an increased risk of developing mental illness and other negative life outcomes. Because of high-quality research with cohorts of offspring with familial risk and increased knowledge about gene-environment interactions, early interventions and preventive strategies are now being developed all over the world. Adolescence is a period characterized by massive changes, both in terms of physical, neurologic, psychological, social, and behavioral aspects. It is also the period of life with the highest risk of experiencing onset of a mental disorder. Therefore, investigating the impact of various risk and resilience factors in adolescence is important.

METHODS

The Danish High-Risk and Resilience Study started data collection in 2012, where 522 7-year-old children were enrolled in the first wave of the study, the VIA 7 study. The cohort was identified through Danish registers based on diagnoses of the parents. A total of 202 children had a parent diagnosed with schizophrenia, 120 children had a parent diagnosed with bipolar disorder, and 200 children had parents without these diagnoses. At age 11 years, all children were assessed for the second time in the VIA 11 study, with a follow-up retention rate of 89%. A comprehensive assessment battery covering domains of psychopathology, neurocognition, social cognition and behavior, motor development and physical health, genetic analyses, attachment, stress, parental functioning, and home environment was carried out at each wave. Magnetic resonance imaging scans of the brain and electroencephalograms were included from age 11 years. This study protocol describes the third wave of assessment, the VIA 15 study, participants being 15 years of age and the full, 3-day-long assessment battery this time including also risk behavior, magnetoencephalography, sleep, and a white noise paradigm. Data collection started on May 1, 2021.

DISCUSSION

We will discuss the importance of longitudinal studies and cross-sectional data collection and how studies like this may inform us about unmet needs and windows of opportunity for future preventive interventions, early illness identification, and treatment in the future.

Bipolar disorder and cannabis use: A bidirectional two-sample Mendelian randomization study

Cannabis use is associated with a number of psychiatric disorders; however, the causal nature of these associations has been difficult to establish. Mendelian randomization (MR) offers a way to infer causality between exposures with known genetic predictors (genome-wide significant single nucleotide polymorphisms [SNPs]) and outcomes of interest. MR has previously been applied to investigate the relationship between lifetime cannabis use (having ever used cannabis) and schizophrenia, depression, and attention deficit hyperactivity disorder (ADHD), but not bipolar disorder, representing a gap in the literature. We conducted a two-sample bidirectional MR study on the relationship between bipolar disorder and lifetime cannabis use. Genetic instruments (SNPs) were obtained from the summary statistics of recent large genome-wide association studies (GWAS). We conducted a two-sample bidirectional MR study on the relationship between bipolar disorder and lifetime cannabis use using inverse variance weighted regression, weighted median regression, and Egger regression. Genetic liability to bipolar disorder was significantly associated with an increased risk of lifetime cannabis use; however, genetic liability to lifetime cannabis use showed no association with the risk of bipolar disorder. The sensitivity analyses showed no evidence for pleiotropic effects. The present findings support a causal effect of liability to bipolar disorder on the risk of using cannabis at least once. No evidence was found for a causal effect of liability to cannabis use on the risk of bipolar disorder. These findings add important new knowledge to the understanding of the complex relationship between cannabis use and psychiatric disorders.

Editorial Perspective: COVID-19 pandemic-related psychopathology in children and adolescents with mental illness

The coronavirus disease (COVID-19) pandemic is likely to have negative health consequences way beyond those caused by the virus per se - including significant psychological distress. Children and adolescents who already live with a mental illness may be particularly vulnerable to the distress associated with the pandemic - due to, for example, fear of the virus as well as the significant societal changes launched to minimize spread of the virus (social distancing and quarantine). In this editorial perspective, we (a) provide data on COVID-19 pandemic-related psychopathology in children and adolescents from a large psychiatric treatment setting in Denmark, (b) give advice on how the likely harmful effects of the COVID-19 pandemic on the mental health of children and adolescents may be minimized, and (c) propose six lines of research into pandemic-related psychopathology with emphasis on children and adolescents. Finally, we underline the necessity of politicians, health authorities, and funding bodies supporting these research initiatives here and now.

Transcriptional regulation in the rat prefrontal cortex and hippocampus after a single administration of psilocybin

BACKGROUND

Psilocybin is a serotonergic psychedelic found in "magic mushrooms" with a putative therapeutic potential for treatment-resistant depression, anxiety, obsessive-compulsive disorder, and addiction. In rodents, psilocybin acutely induces plasticity-related immediate early genes in cortical tissue; however, studies into the effects on subcortical regions, of different doses, and the subsequent translation of corresponding proteins are lacking.

METHODS

We examined the acute effects of a single administration of psilocybin (0.5-20 mg/kg) on the expression of selected genes in the prefrontal cortex and hippocampus. In total, 46 target genes and eight reference genes were assessed using real-time quantitative polymerase chain reaction. Corresponding protein levels of the three most commonly regulated genes were assessed using Western blotting.

RESULTS

In the prefrontal cortex, psilocybin increased the expression of Cebpb, c-Fos, Dups1, Fosb, Junb, Iκβ-α, Nr4a1, P11, Psd95, and Sgk1, and decreased the expression of Clk1. In the hippocampus, psilocybin strongly increased the expression of Arrdc2, Dusp1, Iκβ-α, and Sgk1 in a dose-dependent manner, and decreased the expression of Arc, Clk1, Egr2, and Ptgs2. Protein levels of Sgk1, Dusp1, and Iκβ-α showed only partial agreement with transcriptional patterns, stressing the importance of assessing downstream translation when investigating rapid gene responses.

CONCLUSION

The present study demonstrates that psilocybin rapidly induces gene expression related to neuroplasticity, biased towards the prefrontal cortex, compared to the hippocampus. Our findings provide further evidence for the rapid plasticity-promoting effects of psilocybin.