Patterns of Psychiatric Comorbidity and Genetic Correlations Provide New Insights Into Differences Between Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder

Berit S Solberg; Tetyana Zayats; Maj-Britt Posserud; Anne Halmøy; Anders Engeland; Jan Haavik; Kari Klungsøyr

doi:10.1016/j.biopsych.2019.04.021

Patterns of Psychiatric Comorbidity and Genetic Correlations Provide New Insights Into Differences Between Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder

Biol Psychiatry. 2019 Oct 15;86(8):587-598. doi: 10.1016/j.biopsych.2019.04.021. Epub 2019 Apr 28.

Authors

Berit S Solberg¹, Tetyana Zayats², Maj-Britt Posserud³, Anne Halmøy⁴, Anders Engeland⁵, Jan Haavik⁴, Kari Klungsøyr⁶

Affiliations

¹ Department of Biomedicine, University of Bergen, Bergen, Norway; Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; K.G. Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, Bergen, Norway. Electronic address: bssol2004@yahoo.no.
² Department of Biomedicine, University of Bergen, Bergen, Norway; K.G. Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, Bergen, Norway; Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts.
³ K.G. Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, Bergen, Norway; Department of Clinical Medicine, University of Bergen, Bergen, Norway; Department of Psychiatry, Haukeland University Hospital, Bergen, Norway.
⁴ Department of Biomedicine, University of Bergen, Bergen, Norway; K.G. Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, Bergen, Norway; Department of Psychiatry, Haukeland University Hospital, Bergen, Norway.
⁵ Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; Division of Mental and Physical Health, Norwegian Institute of Public Health, Bergen, Norway.
⁶ Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; K.G. Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, Bergen, Norway; Division of Mental and Physical Health, Norwegian Institute of Public Health, Bergen, Norway.

Abstract

Background: Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) share common genetic factors but seem to have specific patterns of psychiatric comorbidities. There are few systematic studies on adults; therefore, we compared psychiatric comorbidities in adults with these two neurodevelopmental disorders using population-based data and analyzed their genetic correlations to evaluate underlying factors.

Methods: Using data from Norwegian registries, we assessed patterns of psychiatric disorders in adults with ADHD (n = 38,636; 2.3%), ASD (n = 7528; 0.4%), and both diagnoses (n = 1467; 0.1%) compared with the remaining adult population (n = 1,653,575). We calculated their prevalence ratios (PRs) and differences using Poisson regression, also examining sex-specific relations. Genetic correlations (r_g) among ADHD, ASD, and the examined psychiatric disorders were calculated by linkage disequilibrium score regression, exploiting summary statistics from relevant genome-wide association studies.

Results: For all psychiatric comorbidities, PRs differed between ADHD and ASD. Associations were strongest in individuals with ADHD and ADHD+ASD for most comorbidities, in both men and women. The relative prevalence increase of substance use disorder was three times larger in ADHD than in ASD (PR_ADHD, 6.2; 95% confidence interval [CI], 6.1-6.4; PR_ASD, 1.9; 95% CI, 1.7-2.2; p < .001); however, the opposite was true for schizophrenia (PR_ASD, 13.9; 95% CI, 12.7-15.2; PR_ADHD, 4.4; 95% CI, 4.1-4.7; p < .001). Genetic correlations supported these patterns but were significantly different between ADHD and ASD only for the substance use disorder proxies and personality traits (p < .006 for all).

Conclusions: Adults with ADHD, ASD, or both ADHD and ASD have specific patterns of psychiatric comorbidities. This may partly be explained by differences in underlying genetic factors.

Keywords: ADHD; ASD; Genetics; Psychiatric comorbidity; SUD; Schizophrenia.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Attention Deficit Disorder with Hyperactivity / complications
Attention Deficit Disorder with Hyperactivity / epidemiology*
Autism Spectrum Disorder / complications
Autism Spectrum Disorder / epidemiology*
Comorbidity
Cross-Sectional Studies
Female
Humans
Male
Mental Disorders / complications
Mental Disorders / epidemiology
Norway / epidemiology
Registries

Abstract

Publication types

MeSH terms

Grants and funding