Comorbidity with ADHD
Comorbidity and differential diagnosis are different medical concepts. Comorbidity is the simultaneous occurrence of several diseases, differential diagnosis is the determination of which disease certain symptoms belong to. Both concepts are used to determine existing diseases in order to be able to treat them optimally.
1.1. What is comorbidity
Comorbidity refers to several mental or somatic disorders that coexist (conditionally independently of each other) and typically often occur together.
From a statistical point of view, comorbid disorders are characterized by the fact that their joint occurrence is over-random. Consequences of this are that the respective disorders have at least partially common causes or can be (co-)causes of each other. This provides an insight into the possible causes of ADHD.
Mental disorders are very common. Experts estimate a lifetime prevalence of up to 66% for mental disorders. This means that 2/3 of all people suffer from a mental disorder at some point in their lives, with many simply not being detected because the person with ADHD does not seek treatment.1
Many of the disorders listed as comorbidities for children and adults develop in the same way as ADHD
- Purely genetic (common)
- Due to environmental pollution alone (quite rare)
- Through a combination of genes + environment (frequent)
ADHD is often accompanied by comorbid disorders. Comorbidities are the rule rather than the exception in ADHD.
In ADHD, however, comorbidities are often enough not an independent psychiatric entity, but a mere consequence of untreated ADHD.2
Which disorder should be treated first should be decided on the basis of the degree of stress. If this is not clear, it is advisable to treat the ADHD first to see how much the comorbidity is influenced by the ADHD treatment. Often enough, separate treatment is then unnecessary.
For more information, see ⇒ Treatment prioritization for comorbidities In the article ⇒ ADHD treatment guidelines in the chapter ⇒ Treatment and therapy.
1.2. Comorbidity with ADHD
Children with ADHD are 60% to 100% likely to suffer from at least one psychopathological comorbidity (e.g. tic disorder, depression, social behavior disorder, etc.).34
An average of 1.4 comorbidities were found in n = 174 adults with ADHD who were examined 5
Among 575 adults with ADHD, one study found at least one comorbidity in 52.4% (32.9% had one, 12.7% had two, 3.8% had three and 3% had four comorbidities).6
One study found mental comorbidities in 53.9% of 5,840 people with ADHD.7
1.3. Literature
Müller et al. recommend a particularly good book on comorbidities in ADHD:8
Jules Angst (2001), persönlicher Brief an H. Hinterhuber, aus P. Hofmann (Hrsg.) (2002): Dysthymie. Anmerkung: Prof. Dr. Jules Angst von der Psychiatrischen Universitätsklinik Zürich gehörte während seiner aktiven Zeit als Arzt und Wissenschaftler zu den international bekanntesten und renommiertesten epidemiologisch tätigen Psychiatern. Seine oben dargestellte Überzeugung wird von vielen Fachkollegen geteilt.” Zitiert aus Faust, DYSTHYMIE: CHRONISCHE DEPRESSIVE VERSTIMMUNG ↥
Jaeschke RR, Sujkowska E, Sowa-Kućma M (2021): Methylphenidate for attention-deficit/hyperactivity disorder in adults: a narrative review. Psychopharmacology (Berl). 2021 Oct;238(10):2667-2691. doi: 10.1007/s00213-021-05946-0. PMID: 34436651; PMCID: PMC8455398. REVIEW ↥
Gillberg, Gillberg, Rasmussen, Niklasson (2004): Co-existing disorders in ADHD—Implications for diagnosis and intervention; Article in European Child & Adolescent Psychiatry 13 Suppl 1(S1):I80-92 · February 2004; DOI: 10.1007/s00787-004-1008-4 ↥
Schmitt (2014): Veränderungen des QEEG bei Kindern mit einer ADHS nach Neurofeedback-Training der langsamen kortikalen Potentiale; Dissertation, S. 9 ↥
Müller, Candrian, Kropotov (2011): ADHS – Neurodiagnostik in der Praxis, S. 17 ↥
Ohnishi, Kobayashi, Yajima, Koyama, Noguchi (2020): Psychiatric Comorbidities in Adult Attention-deficit/Hyperactivity Disorder: Prevalence and Patterns in the Routine Clinical Setting. Innov Clin Neurosci. 2019 Sep 1;16(9-10):11-16. PMID: 32082943; PMCID: PMC7009330. ↥
Slaby, Hain, Abrams, Mentch, Glessner, Sleiman, Hakonarson (2022): An electronic health record (EHR) phenotype algorithm to identify patients with attention deficit hyperactivity disorders (ADHD) and psychiatric comorbidities. J Neurodev Disord. 2022 Jun 11;14(1):37. doi: 10.1186/s11689-022-09447-9. PMID: 35690720; PMCID: PMC9188139. ↥
Müller, Candrian, Kropotov (2011): ADHS – Neurodiagnostik in der Praxis, Seite 16 ↥