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JAMA Psychiatry Aug 2023Cannabis use is increasing worldwide and is suspected to be associated with increased risk of psychiatric disorders; however, the association with affective disorders...
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.
Topics: Male; Female; Humans; Bipolar Disorder; Depression; Cohort Studies; Prospective Studies; Marijuana Abuse; Substance-Related Disorders; Depressive Disorder, Major
PubMed: 37223912
DOI: 10.1001/jamapsychiatry.2023.1256 -
Nature Medicine Jul 2023Depression is a common psychiatric disorder and a leading cause of disability worldwide. Here we conducted a genome-wide association study meta-analysis of six datasets,... (Meta-Analysis)
Meta-Analysis
Depression is a common psychiatric disorder and a leading cause of disability worldwide. Here we conducted a genome-wide association study meta-analysis of six datasets, including >1.3 million individuals (371,184 with depression) and identified 243 risk loci. Overall, 64 loci were new, including genes encoding glutamate and GABA receptors, which are targets for antidepressant drugs. Intersection with functional genomics data prioritized likely causal genes and revealed new enrichment of prenatal GABAergic neurons, astrocytes and oligodendrocyte lineages. We found depression to be highly polygenic, with ~11,700 variants explaining 90% of the single-nucleotide polymorphism heritability, estimating that >95% of risk variants for other psychiatric disorders (anxiety, schizophrenia, bipolar disorder and attention deficit hyperactivity disorder) were influencing depression risk when both concordant and discordant variants were considered, and nearly all depression risk variants influenced educational attainment. Additionally, depression genetic risk was associated with impaired complex cognition domains. We dissected the genetic and clinical heterogeneity, revealing distinct polygenic architectures across subgroups of depression and demonstrating significantly increased absolute risks for recurrence and psychiatric comorbidity among cases of depression with the highest polygenic burden, with considerable sex differences. The risks were up to 5- and 32-fold higher than cases with the lowest polygenic burden and the background population, respectively. These results deepen the understanding of the biology underlying depression, its disease progression and inform precision medicine approaches to treatment.
Topics: Male; Female; Humans; Genome-Wide Association Study; Depression; Bipolar Disorder; Schizophrenia; Attention Deficit Disorder with Hyperactivity; Polymorphism, Single Nucleotide; Genetic Predisposition to Disease
PubMed: 37464041
DOI: 10.1038/s41591-023-02352-1 -
Journal of Psychopharmacology (Oxford,... Oct 2023Postpartum psychosis (PPP) is a psychiatric emergency that generally warrants acute inpatient care. PPP is marked by the sudden onset of affective and psychotic symptoms... (Review)
Review
BACKGROUND
Postpartum psychosis (PPP) is a psychiatric emergency that generally warrants acute inpatient care. PPP is marked by the sudden onset of affective and psychotic symptoms with a rapid deterioration in mental state. Evidence suggests that PPP is a discrete disorder on the bipolar disorder spectrum with a distinct treatment profile and prognosis.
METHODS
We conducted a PubMed database search for various terms involving PPP and its treatment and included peer-reviewed articles published in English.
OBJECTIVE
To provide a treatment algorithm for the management of PPP based on available evidence.
RESULTS
Pharmacological therapy is the mainstay of PPP management in the acute phase. Evidence points to a combination of antipsychotics and lithium in the acute treatment of PPP. Electroconvulsive therapy can offer a rapid treatment response where required. Lithium appears to have the best evidence for relapse prevention and prophylaxis in PPP. Psychoeducation is essential and psychosocial interventions used in bipolar disorder may be effective in PPP.
CONCLUSION
Early detection and prompt treatment with antipsychotics and lithium, followed by maintenance treatment with lithium, is associated with a favourable prognosis in PPP.
Topics: Female; Humans; Lithium; Psychotic Disorders; Bipolar Disorder; Antipsychotic Agents; Postpartum Period; Algorithms
PubMed: 37515460
DOI: 10.1177/02698811231181573 -
Molecular Psychiatry Sep 2023There has been substantial progress in understanding the genetics of schizophrenia over the past 15 years. This has revealed a highly polygenic condition with the... (Review)
Review
There has been substantial progress in understanding the genetics of schizophrenia over the past 15 years. This has revealed a highly polygenic condition with the majority of the currently explained heritability coming from common alleles of small effect but with additional contributions from rare copy number and coding variants. Many specific genes and loci have been implicated that provide a firm basis upon which mechanistic research can proceed. These point to disturbances in neuronal, and particularly synaptic, functions that are not confined to a small number of brain regions and circuits. Genetic findings have also revealed the nature of schizophrenia's close relationship to other conditions, particularly bipolar disorder and childhood neurodevelopmental disorders, and provided an explanation for how common risk alleles persist in the population in the face of reduced fecundity. Current genomic approaches only potentially explain around 40% of heritability, but only a small proportion of this is attributable to robustly identified loci. The extreme polygenicity poses challenges for understanding biological mechanisms. The high degree of pleiotropy points to the need for more transdiagnostic research and the shortcomings of current diagnostic criteria as means of delineating biologically distinct strata. It also poses challenges for inferring causality in observational and experimental studies in both humans and model systems. Finally, the Eurocentric bias of genomic studies needs to be rectified to maximise benefits and ensure these are felt across diverse communities. Further advances are likely to come through the application of new and emerging technologies, such as whole-genome and long-read sequencing, to large and diverse samples. Substantive progress in biological understanding will require parallel advances in functional genomics and proteomics applied to the brain across developmental stages. For these efforts to succeed in identifying disease mechanisms and defining novel strata they will need to be combined with sufficiently granular phenotypic data.
Topics: Humans; Child; Schizophrenia; Bipolar Disorder; Genome; Genomics; Emotions; Genetic Predisposition to Disease; Genome-Wide Association Study
PubMed: 37853064
DOI: 10.1038/s41380-023-02293-8 -
Molecular Psychiatry Jul 2023Neuropathological mechanisms of manic syndrome or manic episodes in bipolar disorder remain poorly characterised, as the research progress is severely limited by the...
Neuropathological mechanisms of manic syndrome or manic episodes in bipolar disorder remain poorly characterised, as the research progress is severely limited by the paucity of appropriate animal models. Here we developed a novel mania mice model by combining a series of chronic unpredictable rhythm disturbances (CURD), which include disruption of circadian rhythm, sleep deprivation, exposure to cone light, with subsequent interference of followed spotlight, stroboscopic illumination, high-temperature stress, noise disturbance and foot shock. Multiple behavioural and cell biology tests comparing the CURD-model with healthy controls and depressed mice were deployed to validate the model. The manic mice were also tested for the pharmacological effects of various medicinal agents used for treating mania. Finally, we compared plasma indicators of the CURD-model mice and the patients with the manic syndrome. The CURD protocol produced a phenotype replicating manic syndrome. Mice exposed to CURD presented manic behaviours similar to that observed in the amphetamine manic model. These behaviours were distinct from depressive-like behaviours recorded in mice treated with a depression-inducing protocol of chronic unpredictable mild restraint (CUMR). Functional and molecular indicators in the CURD mania model showed multiple similarities with patients with manic syndrome. Treatment with LiCl and valproic acid resulted in behavioural improvements and recovery of molecular indicators. A novel manic mice model induced by environmental stressors and free from genetic or pharmacological interventions is a valuable tool for research into pathological mechanisms of mania.
Topics: Humans; Animals; Mice; Mania; Disease Models, Animal; Bipolar Disorder; Valproic Acid; Sleep Deprivation
PubMed: 36991130
DOI: 10.1038/s41380-023-02037-8 -
Nature Neuroscience Sep 2023The substantial individual heterogeneity that characterizes people with mental illness is often ignored by classical case-control research, which relies on group mean...
The substantial individual heterogeneity that characterizes people with mental illness is often ignored by classical case-control research, which relies on group mean comparisons. Here we present a comprehensive, multiscale characterization of the heterogeneity of gray matter volume (GMV) differences in 1,294 cases diagnosed with one of six conditions (attention-deficit/hyperactivity disorder, autism spectrum disorder, bipolar disorder, depression, obsessive-compulsive disorder and schizophrenia) and 1,465 matched controls. Normative models indicated that person-specific deviations from population expectations for regional GMV were highly heterogeneous, affecting the same area in <7% of people with the same diagnosis. However, these deviations were embedded within common functional circuits and networks in up to 56% of cases. The salience-ventral attention system was implicated transdiagnostically, with other systems selectively involved in depression, bipolar disorder, schizophrenia and attention-deficit/hyperactivity disorder. Phenotypic differences between cases assigned the same diagnosis may thus arise from the heterogeneous localization of specific regional deviations, whereas phenotypic similarities may be attributable to the dysfunction of common functional circuits and networks.
Topics: Humans; Autism Spectrum Disorder; Magnetic Resonance Imaging; Bipolar Disorder; Gray Matter; Obsessive-Compulsive Disorder; Attention Deficit Disorder with Hyperactivity; Brain
PubMed: 37580620
DOI: 10.1038/s41593-023-01404-6