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Co-occurring Conditions


The 2007 National Survey of Children’s Health (NCSH) found that 33% of the children with ADHD had one coexisting condition, 16% had two, and 18% had three or more (Larson 2011):

ADHD and Coexisting Conditions
Coexisting Disorder
Children with ADHD
Children without ADHD
Learning Disability 45% 5%
Conduct Disorder 27% 2%
Anxiety 18% 2%
Depression 15% 1%
Speech Problems 12% 3%

These are the most common co-occurring conditions in children and adolescents according to a study by Elia et al. (2008):

  • Oppositional Defiance Disorder (ODD) was most common, appearing 41% of the time.
  • Minor Depression/Dysthymia (MDDD) was second, with a rate of 22%.
  • Generalized Anxiety Disorder (GAD) was third, appearing 15% of the time.
By ADHD Subtypes
Coexisting Condition
ADHD Inattentive
ADHD Hyperactive-Impulsive
ADHD Combined
Oppositional Defiance Disorder (ODD) 21% 42% 50.7%
Minor Depression/ Dysthymia (MDDD) 21% 21% 21.7%
Generalized Anxiety Disorder (GAD) 19% 19% 12.4%


Learning & Writing Disabilities

31% to 45% of children with ADHD have a learning disability, and vice versa (DuPaul 2013).

“It is estimated that as many as one-third of those with LD also have ADHD” (NCLD 2014).

Boys with ADHD have about a 65% risk of having writing disabilities, compared to 16.5% of boys without ADHD, while girls with ADHD have a 57% risk compared to a 9.4% risk for girls without ADHD (Yoshimasu 2011).


Heart Disease

ADHD appears to be more prevalent in children with heart disease. A study by Kraut et al. (2013) examined 13,460 children using ADHD medication and found that 2% had a preexisting heart disorder compared with 1.2% of children not using medication.



The prevalence of coexisting conditions found by the National Comorbidity Survey Replication (NCS-R) in 3,199 adults with ADHD (ages 18-44) is as follows (Kessler et al. 2006):

Coexisting Condition
Adults with ADHD
Adults without ADHD
Any mood disorder 38.3% 11.1%
Major depressive disorder 18.6% 7.8%
Dysthymia (mild, chronic depression) 12.3% 1.9%
Bipolar disorder 19.4% 3.1%
Any anxiety disorder 47.1% 19.5%
Generalized anxiety disorder 8.0% 2.6%
PTSD 11.9% 3.3%
Panic disorder 8.9% 3.1%
Agoraphobia 4.0% 0.7%
Specific phobia 22.7% 9.5%
Social phobia 29.3% 7.8%
Obsessive-compulsive disorder (OCD) 2.7% 1.3%
Any substance abuse disorder 15.2% 5.6%
Alcohol abuse 5.9% 2.4%
Alcohol dependence 5.8% 2.0%
Drug abuse 2.4% 1.4%
Drug dependence 4.4% 0.6%
Intermittent explosive disorder 19.6% 6.1%



Obesity prevalence increases by about 70% in adults with ADHD compared to adults without ADHD. In children with ADHD, obesity prevalence increases by about 40% when compared to children without ADHD (Cortese, 2015).

Analysis of data from the Collaborative Psychiatric Epidemiology Surveys found the following association between adult ADHD and obesity (Pagoto, 2009):

Coexisting Condition
Adults with ADHD
Adults without ADHD
Overweight 33.0% 28.8%
Obese 29.4% 21.6%



Cortese, Samuele et al. (2015). Association Between ADHD and Obesity: A Systematic Review and Meta-Analysis. American Journal of Psychiatry (Ahead of Print).

Elia, Josephine et al. (2008). ADHD characteristics: I. Concurrent co-morbidity patterns in children & adolescents. Child and Adolescent Psychiatry and Mental Health, 2:15.

DuPaul, George J. et al. (2013). Comorbidity of LD and ADHD: Implications of DSM-5 for Assessment and Treatment. Journal of Learning Disabilities 46(1):4351.

Kessler et al. (April 2006). The Prevalence and Correlates of Adult ADHD in the United States: Results From the National Comorbidity Survey Replication, American Journal of Psychiatry 163(5):71.

Kraut AA et al. (2013). Comorbidities in ADHD children treated with methylphenidate: a database study. BMC Psychiatry 13:11.

Larson, Kandyce et al. (2011). Patterns of Comorbidity, Functioning, and Service Use for US Children With ADHD, 2007. Pediatrics, 127(3):462470.

National Center for Learning Disabilities (NCLD) (2014). The State of Learning Disabilities: Facts, Trends and Indicators, New York.

Pagoto, Sherry L. et al. (March 2009). Association Between Adult Attention Deficit/Hyperactivity Disorder and Obesity in the US Population. Obesity 17(3):539544.

Yoshimasu, Kouichi et al. (September 2011). Written-Language Disorder Among Children With and Without ADHD in a Population-Based Birth Cohort. Pediatrics 128(3):e605e612.


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