SHARELike all neurodivergent conditions, ADHD is complex – there are varying factors that influence its presentation, and it often co-occurs with one or more psychiatric, learning, or neurodevelopmental disorder, which complicates the diagnosis and treatment. More than half of children with ADHD have at least one co-occurring condition, or comorbidity, and in adults, that number goes up to 80%.
What is a comorbidity?
A comorbidity means that a person has two or more conditions that exist simultaneously, and both conditions need to be managed. Comorbidities can be wide-ranging, and their severity can go from mild to serious
| Category | Cortical wiring problems | Problems regulating emotions | Tic disorders |
|---|---|---|---|
| Common disorders | • Learning disabilities • Language disabilities • Dyslexia: difficulty reading words • Dysgraphia: difficulty writing • Dyscalculia: difficulty doing calculations • Fine and gross motor difficulties • Executive function difficulties | • Depression • Oppositional Defiant Disorder (ODD) • Generalized Anxiety Disorder (GAD) • Autism Spectrum Disorder (ASD) • Conduct disorder • Obsessive-compulsive disorder (OCD) • Bipolar disorder • Disruptive Mood Dysregulation Disorder (persistently irritable, angry or annoyed) • Substance Use Disorder (amongst teens and adults) | - Motor tics (involuntary eye blinking, head jerking, or repeated gestures) - Oral tics (grunting, random blurting, and in very rare cases, obscene words or phrases) - Tourette’s syndrome (multiple motor and vocal tics) |
| General treatment | • Lifestyle changes • Academic accommodations • Special education services | • Cognitive Behaviour Therapy • Individual therapy • Counselling • Skills training • Medication (such as selective serotonin reuptake inhibitors, or SSRIs, which generally can be used in conjunction with ADHD medications) • For Substance Use Disorder: in-patient and out-patient treatment | • Behavioural Interventions • Medication • School support and academic accommodations |
What causes it?
Experts suggest that ADHD and co-occurring conditions arise from:
• Genetic neuropsychological dysfunctions -there are strong familial links between ADHD and psychiatric comorbidities such as bipolar disorders, for instance.
• Neurobiological differences – the differences in volume and activity in the brain’s frontal lobe, which is responsible for attention, behaviour selection, and emotion. Studies of neurotransmitters have also pointed to abnormalities in dopamine, norepinephrine and signalling.
This also explains why ADHD differs from person to person.
How do you know if it’s a comorbid condition, and not a secondary condition to ADHD symptoms?
Secondary conditions typically start under certain circumstances, e.g. a child may get anxious when doing homework or only at school. This would be a sign that the anxiety is secondary to ADHD.
Comorbid disorders are pervasive and chronic – they occur in every life situation and may be apparent from early childhood, e.g. ADHD-related mood shifts are usually triggered by life events, while depression is chronic and often hereditary.
How is it diagnosed?
If after a child starts ADHD treatment, and they continue to experience psychiatric symptoms, the next step is to determine whether the symptoms are secondary to ADHD (which can be treated by fine-tuning the
treatment plan) or if it’s a comorbid disorder that requires additional treatment. A diagnosis can only be reached through careful observation of symptoms and a comprehensive psychological evaluation.
Through awareness of these conditions, you can get a better understanding of your child’s ADHD. Consult with your child’s doctor if you suspect that your child may have more than ADHD.
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References:
1. Cerulli, T. (2022). What Is Complex ADHD? Symptoms, Diagnosis & Treatment. ADDitude. Accessed on 22 August 2022. Available from https://www.additudemag.com/complex-adhd-symptoms-diagnosis-treatment/ [ADD3]
2. CHADD. (n.d.). ADHD and Coexisting Conditions: Neurodevelopmental Disorders. CHADD [Online]. Accessed on 24 August 2022. Available from https://chadd.org/about-adhd/adhd-and-co-occurring-conditions-infographic/ [CHADD2]
3. Katzman, M.A., Bilkey, T.S., Chokka, P.R. et al. (2017). Adult ADHD and Comorbid Disorders: Clinical Implications of a Dimensional Approach. BMC Psychiatry 17, 302 https://doi.org/10.1186/s12888-017-1463-3 [BMC]
4. Robb, A S. (2022). Beyond the Core Symptoms of ADHD in Children: Comorbid Screening and Treatment Guidance. ADDitude [Online]. Accessed on 24 August 2022. Available from https://www.additudemag.com/adhd-in-children-symptoms-comorbidities/ [ADD2]
5. Rommelse, N.N.J., Altink, M.E., Fliers, E.A. et al. (2009). Comorbid Problems in ADHD: Degree of Association, Shared Endophenotypes, and Formation of Distinct Subtypes. Implications for a Future DSM . Journal of Abnormal Child Psychology. 37, 793–804 https://doi.org/10.1007/s10802-009-9312-6 [CP]
6. Silver, L. (2022). When It’s Not Just ADHD: Symptoms of Comorbid Conditions. ADDitude [Online]. Accessed on 17 August 2022. Available from https://www.additudemag.com/when-its-not-just-adhd/ [ADD]
7. The Mini ADHD Coach. (2021). ADHD Comorbidity: Learn the Most Cooccurring Conditions. The Mini ADHD Coach [Online]. Accessed on 24 August 2022. Available from https://www.theminiadhdcoach.com/articles/adhd-comorbidity [TMAC]
