ADHD and Comorbidity

I think she's more along the autistic spectrum than just ADHD. I think there's quite few Asperger's traits in there but she doesn't want any more labels.

The last few decades have seen a substantial increase in the emotional problems experienced by adolescents in England [1]. The transition from childhood to adulthood is therefore difficult for many teenagers who strive for independence and autonomy while coping with greater social expectations, leaving school and going into further education, making new friends, getting a job, and taking greater responsibility for their actions and behaviour.

These transitions provoke some level of anxiety and worry among most teenagers. Teenagers and adults with ADHD, however, may struggle more as they have fewer coping resources than their peers to help them deal with the challenges and difficulties that they will face [2,3]; additionally their mood may be labile, for example, with extreme presentations of excitement, irritability, frustration, anxiety and anger [4,5].

My younger brother, and my cousin have ADHD. My cousin's got Asperger's as well...and my younger brother's also got Oppositional Defiant Disorder.

It appears to be the rule rather than the exception for ADHD children to present with a second psychiatric disorder with reports of up to two-thirds of children with ADHD having one or more comorbid conditions, including oppositional defiant and conduct disorder, anxiety and mood disorders, tic disorders and autistic spectrum disorders [6-9]. Multiple presentations to health and social services have been reported by individuals who were not diagnosed until adulthood [10,11].

Treatment with stimulant medication in childhood may not be protective as follow-up data from 208 children with ADHD who had been treated with stimulants found that 23% had a psychiatric admission in adulthood (mean age of 31). Conduct problems in childhood were predictive (hazard ratio = 2.3 for boys and 2.4 for girls) [12].

Disruptive Behaviour Disorders

The most common comorbid conditions in childhood are the disruptive disorders of conduct disorder (CD) and oppositional defiant disorder (ODD) which together affect 40-60% of children and adolescents with ADHD [13]. ODD is a recurrent pattern of negativistic, defiant disobedient and hostile behaviour towards authority figures that becomes evident before age 8 and not later than early adolescence.

By contrast CD, which has a later onset usually after the age of 10, is characterised by a disregard for the rules and norms of society. Problems associated with CD include physical and verbal aggression (e.g. starting fights), defiance (e.g. staying out later than their curfew), offending (e.g. theft, vandalism or setting fires), and school truancy. ADHD and CD occur together at a rate greater than chance [14] and together they are clinically and genetically more severe variants of their independent disorders [15], thus presenting young people with a 'double dose' of self-management problems. While boys more often have comorbid conduct problems, girls with ADHD and ODD or conduct disorder might have more social problems than boys [16,17].

Anxiety Disorders

At a pub, if there's like a group of people, I don't go into that group, I stay on the outskirts of the group.

Teenagers with ADHD often feel different in some way compared with their peers. Thus they may be particularly concerned with their self-image and desire to ‘fit in’. In addition they have a history of underachieving their academic and social potential, leading to a lack of confidence and poor self-efficacy. This mismatch between what they want and believe they should be able to achieve and their actual performance may lead to the development of anxiety.

Anxiety disorders co-occur in approximately 20% of adolescents with ADHD, the most common being generalised anxiety disorder, obsessive compulsive disorder, separation anxiety disorder and social phobia [18].

In a survey of adults, 47% of adults with ADHD had developed an anxiety disorder compared with 19.5% of those without ADHD (odds ratio 3.7) [19]. Whilst lower level anxiety may be more pronounced, as a comorbid condition it will exacerbate low self-esteem, stress intolerance and aspects of cognition such as impairment in working memory [20]. Symptoms such as restlessness and inattention may appear similar in the two disorders and it is important to determine which is primary as this may help in deliver of effective treatment.

Mood Disorders

...the smallest thing though will pop my bubble and bring me all the way down. I just have to fight that I guess, I just try my hardest not to be sad, because I don't like being sad. But as a child I was very, very, very, very anxious and extremely depressed.

Young people with ADHD have often experienced a lot of criticism and negative feedback in their lives. They experience disruption to interpersonal relationships at school, and with family and friends. Together with their difficulty in self-regulation, this means that they may be vulnerable to depressive symptoms. These symptoms may be mild but persistent leading to low mood, poor motivation and a sense of hopelessness about the future. In turn this may exacerbate concentration problems.

In a US nationally representative household survey of 18-44 year old respondents, 38% of adults with ADHD reported they had developed a mood disorder compared with 11% of those without ADHD [19]. A gender difference may exist as major depression has been reported to co-occur among adolescent females with ADHD at a younger age, with a longer duration and to be associated with greater impairment in personal, social and occupational functioning [21].

A follow-up of Danish children into adulthood found that females may have greater vulnerability for mood disorders leading to inpatient admissions [12]. In cases of ADHD and comorbid depression, it is important to bear in mind that impulsivity may increase the risk that a young person will act out on suicidal ideation.

Tic Disorders

Tic disorders are most commonly associated with motor tics such as repeated eye blinking and facial twitching and/or phonic (or vocal) tics such as grunting and sniffing [22]. Up to 50% of children with tic disorders, including Tourette’s syndrome (TS), also meet diagnostic criteria for ADHD [23] and children with these comorbid conditions are at increased risk for externalising and internalising behaviour problems. However, the risk appears to be associated with the co-occurrence of ADHD as children with TS alone tend to do better [29].

In contrast to previous thinking, treatment of comorbid ADHD with stimulant medication does not have an adverse effect on tics in the majority of cases [24, 30]. Since tic disorders generally decrease in severity with age, these are seldom a serious problem in the treatment of adults.

Autistic Spectrum Disorders

He recently got a diagnosis of ASD, and I always felt there was something else besides the ADHD.

Autism spectrum disorder (ASD; including autism and Asperger’s syndrome) is characterised by life-long difficulties in reciprocal social communication and stereotyped and repetitive behaviours and interests (International Classification of Diseases, tenth edition - ICD-10) [25].

The overlap between ADHD and ASD has become increasingly recognised in the past few years and a community twin study reported a strong genetic link between ADHD and ASD, with 41% of children with ASD also having ADHD symptoms and 22% with suspected ADHD (based on positive screening scales for ADHD symptoms) also had a diagnosis of ASD [31].

Problems with attention are common for people with ASD [27] and it has been suggested that this may contribute towards the behavioural and cognitive difficulties of people with ASD [28]. Overall, young people with ADHD and ASD may both have problems managing attention and emotions and those who are diagnosed with both ADHD and ASD may experience particular difficulties with cognitive control.

Key Points from Module 3

Box 1: Key points from Module 3- ADHD and Common Comorbidities
  • The extent of comorbidity associated with ADHD is high; two-thirds of children have at least one other psychiatric disorder, including other disruptive behavioural disorders, anxiety disorders, mood disorders, tic disorders, and autistic spectrum disorders.
  • Disruptive behaviour disorders are the most common, especially for males, and up to 60% of children and adolescents with ADHD will also have conduct disorder or oppositional defiant disorder.
  • Comorbid anxiety problems can exacerbate feelings of low self-esteem commonly experienced by those with ADHD.
  • Adolescent females with ADHD are at increased risk of major depression, which affects them at a younger age, over a longer duration and is associated with greater impairment in personal, social and occupational functioning.
  • Children with co-occurring ADHD and Tourette's/tics are at increased risk for externalising and internalising behaviour problems.
  • There is a strong genetic link between ADHD and autistic spectrum disorders, both of which are characterised by problems managing attention and emotions.
  • The order of treatment may depend on clinical judgement of which disorder is driving the mental state changes and/or presenting level of behavioural impairments.


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[2] Young, S., Heptinstall, E., Sonuga-Barke, E.J.S., Chadwick, O., & Taylor, E. (2005). The adolescent outcome of hyperactive girls: Interpersonal relationships and coping mechanisms. European Child & Adolescent Psychiatry, 14(5), 245-253.

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[6] Biederman, J., Newcorn, J., & Sprich, S. (1991). Comorbidity of attention deficit hyperactivity disorder with conduct, depressive, anxiety, and other disorders. American Journal of Psychiatry, 148(5), 564-577.

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[10] Huntley, Z., & Young, S. (online). Alcohol and Substance Use History Among ADHD Adults: The Relationship With Persistent and Remitting Symptoms, Personality, Employment, and History of Service Use. Journal of Attention Disorders,

[11] Young, S., Toone, B., & Tyson, C. (2003). Comorbidity and psychosocial profile of adults with Attention Deficit Hyperactivity Disorder. Personality and Individual Differences, 35(4), 743-755.

[12] Dalsgaard, S., Mortensen, P.B., Frydenberg, M., & Thomsen, P.H. (2002). Conduct problems, gender and adult psychiatric outcome of children with attention deficit hyperactivity disorder. British Journal of Psychiatry, 181, 416–421.

[13] Wolraich, M.L., Hannah, J.N., Pinnock, T.Y., Baumgaertel, A., & Brown, J. (1996). Comparison of diagnostic criteria for attention deficit hyperactivity disorder in a county-wide sample. Journal of the American Academy of Child and Adolescent Psychiatry, 35(3), 319-324.

[14] Waschbusch, D.A. (2002). A meta-analytic examination of comorbid hyperactive impulsive attention problems and conduct problems. Psychological Bulletin, 128(1), 118–150.

[15] Thapar, A., Harrington, R., & McGuffin, P. (2001). Examining the comorbidity of ADHD-related behaviours and conduct problems using a twin study design. British Journal of Psychiatry, 179, 224–229.

[16] Carlson, C.L., Tamm, L., & Miranda, G. (1997). Gender differences in children with ADHD, ODD, and co-occurring ADHD/ODD identified in a school population. Journal of the American Academy of Child and Adolescent Psychiatry, 36(12), 1706-1714.

[17] Gaub, M., & Carlson, C. L. (1997). Gender differences in ADHD:A meta-analysis and critical review. Journal of the American Academy of Child and Adolescent Psychiatry, 36(8), 1036-1045.

[18] Geller, D.A., Biederman, J., Griffin, S., Jones, J., & Lefkowitz, T.R. (1996). Comorbidity of juvenile Obsessive-Compulsive Disorder with disruptive behavior disorders. Journal of the American Academic of Child and Adolescent Psychiatry, 35(12), 1637-1646.

[19] Kessler, R.C., Adler, L., Barkley, R., Biederman, J., Conners, C.K., Demler, O., et al. (2006). The prevalence and correlates of adult ADHD in the United States: Results from the national comorbidity survey replication. American Journal of Psychiatry, 163(4), 716–723.

[20] Tannock, R. (2000). Attention-deficit/hyperactivity disorder with anxiety disorders. In T.E. Brown (Ed.). Attention deficit disorders and comorbidities in children, adolescents, and adults (pp.125-170). Washington, DC: American Psychiatric Press.

[21] Biederman, J., Ball, S.W., Monuteaux, M.C., Mick, E., Spencer, T.J., McCreary, M., et al. (2008). New insights into the comorbidity between ADHD and major depression in adolescent and young adult females. Journal of the American Academy of Child & Adolescent Psychiatry, 47(4), 426-434.

[22] Cath, D.C., Hedderly, T., Ludolph, A.G., Stern, J., Murphy, T., Hartmann, A., et al. (2011). European clinical guidelines for Tourette Syndrome and other tic disorders. Part I: assessment. European Child and Adolescent Psychiatry, 20(4), 155-171.

[23] Rothenberger, A., Roessner, V., Banaschewski, T., Leckman, J.F. (2007). Co-existence of tic disorders and attention-deficit/hyperactivity disorder - recent advances in understanding and treatment. European Child and Adolescent Psychiatry, 16 (Suppl 1): 1-4.

[24] Roessner, V., Plessen, K.J., Rothenerger, A., Ludolph, A.G., Rizzo, R., Skov, L., et al. (2011). European clinical guidelines for Tourette syndrome and other tic disorders. Part II: pharmacological treatment. European Child and Adolescent Psychiatry, 20, 173-196.

[25] The ICD-10 classification of mental and behavioural disorders. Clinical descriptions and diagnostic guidelines. Geneva:World Health Organization; 1994.

[26] American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th edn: Washington, DC., 1994.

[27] Sturm, H., Fernell, E., & Gillberg, C., (2004). Autism spectrum disorders in children with normal intellectual levels: associated impairments and subgroups. Developmental Medicine and Child Neurology, 46(7), 444-447.

[28] Allen, G,, & Courchesne, E. (2001) Attention function and dysfunction in autism. Front Biosci, Feb 1;6:D105-19.

[29] Carter, A.S., O’Donnell, D.A., Schultz, R.T., Scahill, L., Leckman, J.F., & Pauls, D.L. (2000). Social and emotional adjustment in children affected with Gilles de la Tourette’s Syndrome: Associations with ADHD and family functioning. Journal of Child Psychology and Psychiatry, 41(2), 215-223.

[30] Poncin, Y., Sukhodolsky, D., McGuire, J., & Scahill, L. (2007). Drug and non-drug treatments of children with ADHD and tic disorders. European Child & Adolescent Psychiatry, 16(Suppl 1), 78-88.

[31] Ronald, A., Simonoff, E., Kuntsi, J., Asherson, P., & Plomin, R. (2008). Evidence for overlapping genetic influences on autistic and ADHD behaviours in a community twin sample. Journal of Child Psychology and Psychiatry, 49(5), 535–542.

[32] National Institute for Clinical Excellence. (2009). Attention deficit hyperactivity disorder: Diagnosis and management of ADHD in children, young people and adults. NICE clinical guideline 72. London

Further Reading and Useful Resources

Young, S., Murphy, C.M., & Coghill, D. (2011). Avoiding the 'twilight zone': Guidance and recommendations on ADHD and the transition between child and adult services. BMC Psychiatry. 11:174,

Young, S., & Bramham, J. (2012). Cognitive Behavioural Therapy for ADHD Adolescents and Adults: A Psychological Guide to Practice, Second Edition. Chichester: John Wiley & Sons.

Young, S., Fitzgerald, M., & Postma, M.J. (2013). ADHD: making the invisible visible An Expert White Paper on attention-deficit hyperactivity disorder (ADHD): policy solutions to address the societal impact, costs and long term outcomes, in support of affected individuals,

The National Autistic Society; Autism and ADHD:

ADHD and Anxiety Disorders: