Specific anxiety disorders and subsequent risk for bipolar disorder: a nationwide study

Trends in the incidence and DALYs of bipolar disorder at global, regional, and national levels: Results from the global burden of Disease Study 2017

The objective of this study is to assess the global, regional, and national burden of bipolar disorder (BPD) from 1990 to 2017, by gender, age, and social-demographic index (SDI) from the 2017 Global Burden of Disease (GBD) study. We collected detailed information from GBD on the numbers of incidence cases and disability-adjusted life years (DALYs), age-standardized incidence rate (ASIR), and age-standardized DALYs rate (ASDR) during 1990-2017. Estimated annual percentage changes (EAPCs) were calculated to assess ASIR and ASDR trends. GBD data estimated that BPD incidences increased by 47.74%, from 3.06 million in 1990 to 4.53 million in 2017, and the DALYs increased by 54.4%, from 6.02 million in 1990 to 9.29 million in 2017. Over the 28-year period between 1990 and 2017, the ASIR and ASDR increased only slightly (EAPC = 0.14 and 0.05 for ASIR and ASDR, respectively). Subjects aged 10-19 years contributed the most to the total number of incidence cases, while those aged 20-44 years contributed the most to the number of DALYs. The ASIR and ASDR were highest in tropical Latin America and lowest in East Asia. Areas in the lowest sociodemographic index (SDI) quintile showed the highest ASIR (about 64/100,000), and those in the highest SDI quintile showed the highest ASDR (about 140/100,000). In conclusion, while the ASIR and ASDR due to BPD have been stable, the absolute incidence and DALYs remain high, which represents an increasing burden on health-care systems.

Incidence Rates and Cumulative Incidences of the Full Spectrum of Diagnosed Mental Disorders in Childhood and Adolescence

IMPORTANCE

Knowledge about the epidemiology of mental disorders in children and adolescents is essential for research and planning of health services. Surveys can provide prevalence rates, whereas population-based registers are instrumental to obtain precise estimates of incidence rates and risks.

OBJECTIVE

To estimate age- and sex-specific incidence rates and risks of being diagnosed with any mental disorder during childhood and adolescence.

DESIGN

This cohort study included all individuals born in Denmark from January 1, 1995, through December 31, 2016 (1.3 million), and followed up from birth until December 31, 2016, or the date of death, emigration, disappearance, or diagnosis of 1 of the mental disorders examined (14.4 million person-years of follow-up). Data were analyzed from September 14, 2018, through June 11, 2019.

EXPOSURES

Age and sex.

MAIN OUTCOMES AND MEASURES

Incidence rates and cumulative incidences of all mental disorders according to the ICD-10 Classification of Mental and Behavioral Disorders: Diagnostic Criteria for Research, diagnosed before 18 years of age during the study period.

RESULTS

A total of 99 926 individuals (15.01%; 95% CI, 14.98%-15.17%), including 41 350 girls (14.63%; 95% CI, 14.48%-14.77%) and 58 576 boys (15.51%; 95% CI, 15.18%-15.84%), were diagnosed with a mental disorder before 18 years of age. Anxiety disorder was the most common diagnosis in girls (7.85%; 95% CI, 7.74%-7.97%); attention-deficit/hyperactivity disorder (ADHD) was the most common in boys (5.90%; 95% CI, 5.76%-6.03%). Girls had a higher risk than boys of schizophrenia (0.76% [95% CI, 0.72%-0.80%] vs 0.48% [95% CI, 0.39%-0.59%]), obsessive-compulsive disorder (0.96% [95% CI, 0.92%-1.00%] vs 0.63% [95% CI, 0.56%-0.72%]), and mood disorders (2.54% [95% CI, 2.47%-2.61%] vs 1.10% [95% CI, 0.84%-1.21%]). Incidence peaked earlier in boys than girls in ADHD (8 vs 17 years of age), intellectual disability (5 vs 14 years of age), and other developmental disorders (5 vs 16 years of age). The overall risk of being diagnosed with a mental disorder before 6 years of age was 2.13% (95% CI, 2.11%-2.16%) and was higher in boys (2.78% [95% CI, 2.44%-3.15%]) than in girls (1.45% [95% CI, 1.42%-1.49%]).

CONCLUSIONS AND RELEVANCE

This nationwide population-based cohort study provides a first comprehensive assessment of the incidence and risks of mental disorders in childhood and adolescence. By 18 years of age, 15.01% of children and adolescents in this study were diagnosed with a mental disorder. The incidence of several neurodevelopmental disorders peaked in late adolescence in girls, suggesting possible delayed detection. The distinct signatures of the different mental disorders with respect to sex and age may have important implications for service planning and etiological research.

Genetics of Anxiety Disorders

PURPOSE OF REVIEW

Anxiety disorders are among the most common mental disorders with a lifetime prevalence of over 20%. Clinically, anxiety is not thought of as a homogenous disorder, but is subclassified in generalized, panic, and phobic anxiety disorder. Anxiety disorders are moderately heritable. This review will explore recent genetic and epigenetic approaches to anxiety disorders explaining differential susceptibility risk.

RECENT FINDINGS

A substantial portion of the variance in susceptibility risk can be explained by differential inherited and acquired genetic and epigenetic risk. Available data suggest that anxiety disorders are highly complex and polygenic. Despite the substantial progress in genetic research over the last decade, only few risk loci for anxiety disorders have been identified so far. This review will cover recent findings from large-scale genome-wide association studies as well as newer epigenome-wide studies. Progress in this area will likely require analysis of much larger sample sizes than have been reported to date. We discuss prospects for clinical translation of genetic findings and future directions for research.

An evaluation of the impact of co-occurring anxiety and substance use disorder on bipolar disorder illness outcomes in STEP-BD

BACKGROUND

Anxiety disorder (AD) and substance use disorder (SUD) highly co-occur with bipolar disorder (BD). AD and/or SUD co-occurrence is associated with poorer clinical outcomes in BD. However, respective associations between AD and/or SUD diagnoses and BD outcomes require clarification. Baseline data from the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) were therefore utilized to investigate independent and simultaneous contributions of ADs and SUDs on clinical variables in BD.

METHODS

Two latent factors, "pathological anxiety" and "substance use problems," were derived from presence/absence of lifetime AD and SUD diagnoses. Latent dimensions' associations with clinical variables, obtained from the Affective Disorders Evaluation, Mini-International Neuropsychiatric Interview and Range of Impaired Functioning, were estimated via structural equation modeling (SEM).

RESULTS

Modeled independently, pathological anxiety and substance use problems were significantly associated with several variables. Yet when modeled simultaneously, pathological anxiety's associations with functional impairment, past-year rapid cycling, and past-year %time spent anxious and depressed remained while most variables' associations with substance use problems became non-significant. The only significant latent-factor interaction evidenced was for age of BD onset.

LIMITATIONS

Analyses were limited to lifetime diagnoses and causality may not be inferred given cross-sectional data.

CONCLUSIONS

ADs and SUDs impact on BD was mostly additive rather than synergistic. Findings highlight the potentially understated importance of treating inter-episodic anxiety in BD as it may exacerbate mood symptoms, increasing functional impairment and risk for subsequent mood episodes.

Prevalence of current anxiety disorders in people with bipolar disorder during euthymia: a meta-analysis

BACKGROUND

Anxiety disorders are highly prevalent in people with bipolar disorder, but it is not clear how many have anxiety disorders even at times when they are free of major mood episodes. We aimed to establish what proportion of euthymic individuals with bipolar disorder meet diagnostic criteria for anxiety disorders.

METHOD

We performed a random-effects meta-analysis of prevalence rates of current DSM-III- and DSM-IV-defined anxiety disorders (panic disorder, agoraphobia, social anxiety disorder, generalized anxiety disorder, specific phobia, obsessive-compulsive disorder, post-traumatic stress disorder, and anxiety disorder not otherwise specified) in euthymic adults with bipolar disorder in studies published by 31 December 2015.

RESULTS

Across 10 samples with 2120 individuals with bipolar disorder, 34.7% met diagnostic criteria for one or more anxiety disorders during euthymia [95% confidence interval (CI) 23.9-45.5%]. Direct comparison of 189 euthymic individuals with bipolar disorder and 17 109 population controls across three studies showed a 4.6-fold increase (risk ratio 4.60, 95% CI 2.37-8.92, p < 0.001) in prevalence of anxiety disorders in those with bipolar disorder.

CONCLUSIONS

These findings suggest that anxiety disorders are common in people with bipolar disorder even when their mood is adequately controlled. Euthymic people with bipolar disorder should be routinely assessed for anxiety disorders and anxiety-focused treatment should be initiated if indicated.