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Specialist Advice — 5 minutes

Trouble concentrating? It could be ADHD.

Michel Cameron, PhD
Michel Cameron, PhD
Pharmacogenomics Director

“He’s always last minute.”

“His parents aren’t strict enough. That’s why he doesn’t listen.”

“He doesn’t keep up because he doesn’t concentrate.”

“If he wanted to, he could.”

These are terms that people living with attention deficit disorder with or without hyperactivity (ADHD) have often heard. Living with ADHD is obviously challenging, but the more you understand the disorder, the better you can learn to control it.

Fact: It is estimated that 5 to 9% of children and teenagers and 3 to 5% of adults suffer from ADHD [1]. These people are also more likely to suffer from depression, mood disorders, anxiety and sleep disorders [2].

Diagnosing ADHD

ADHD is one of the most common psychiatric disorders in childhood, and it persists into adulthood in about 60% of cases. ADHD is now recognized by experts as a neurodevelopmental disorder, but, like most mood disorders, it is not always easy to diagnose, especially when accompanied by other disorders or diseases, such as oppositional defiant disorder, language disorders and anxiety [3-5]. Diagnostic tests must be performed by a pediatrician or mental health professional experienced in diagnosing and treating ADHD.

Diagnosis is based on an assessment of symptoms of inattention and hyperactivity-impulsivity, as well as an overall assessment of psychiatric health [6]. Sometimes, failure of a treatment may be due to the fact that a psychiatric condition has not been detected and treated, which may worsen the imbalance.

When school grades are not up to standard, ADHD is often the main suspect for parents and teachers looking for a culprit. However, although pressure to perform in school is an incentive to correct the problem quickly, a comprehensive and detailed assessment of the student will reduce the risk of missing a component of the problem and making the situation worse.

The role of genetics

The exact cause of ADHD has not yet been clearly defined, but a recent study confirms that genetics plays a very important role. A person’s DNA may predispose them to develop ADHD [7]. Other factors are more likely to be related to environment, i.e. family life, diet, lifestyle, etc. Currently, there is no genetic test to predict the risk of developing ADHD.

A parent with ADHD has a 50% chance of having a child with ADHD [8].


The most effective treatment for ADHD is usually a combination of medication with psychological and behavioural therapies. It is important to have close co-operation between therapists, doctors, teachers and parents. Team meetings help ensure that a treatment is successful.


Medication often reduces hyperactivity and improves concentration. The doctor should carefully monitor the dosage of the stimulant drug to determine the most effective amount and identify any side effects. In recent years, the media hype surrounding ADHD has led to increasing concern about the rising number of prescriptions for psychostimulants [9-10].

Psychological therapy

Behaviour modification, often combined with specific educational interventions, may be the most recommended therapy for children and adults.

Living with ADHD also has its advantages. Hyperactivity, for example, can be useful for people who need to show endurance in their daily lives. By seeking to understand their condition, it is possible to make the best of it in order to develop their full potential.

  1. Polanczyk, G. et al., “The Worldwide Prevalence of ADHD: A Systematic Review and Metaregression Analysis.” American Journal of Psychiatry (2007). Vol. 164, #6, 942-948.
  2. Jensen, P.S., et al. “ADHD comorbidity findings from the MTA study: comparing comorbid subgroups.” J Am Acad Child Adolesc Psychiatry (2001). Vol. 40, #2, 147-58.
  3. Goldman, L.S. et al. “Diagnosis and treatment of attention-deficit/hyperactivity disorder in children and adolescents.” JAMA (1998): Vol. 279, #14, 1100-1107.
  4. Sciberras, E. et al. “Language problems in children with ADHD: a community-based study.” Pediatrics (2014): Vol. 133, #5, 793-800.
  5. Charach, A. et al. “Attention Deficit/Hyperactivity Disorder: Effectiveness of Treatment in At-Risk Preschoolers; Long-Term Effectiveness in All Ages; and Variability in Prevalence, Diagnosis, and Treatment.” AHRQ Comparative Effectiveness Reviews, #44 (Oct. 2011): Rockville, MD.
  6. CADDRA. “Canadian ADHD Practice Guidelines.” 4th Edition (2018).
  7. Demontis et al. “Discovery of the first genome-wide significant risk loci for attention deficit/hyperactivity disorder.” Nature Genetics (2019), #51, 63-75.
  8. Faraone, S.V. and A.E. Doyle. “The nature and heritability of attention-deficit/hyperactivity disorder.” Child and Adolescent Psychiatric Clinics of North America (2001): #10, 299-316.
  9. Ministère de la Santé et des Services sociaux du Québec. “Trouble de déficit de l’attention/hyperactivité — Agir ensemble pour mieux soutenir les jeunes – Document de soutien à la formation.” (2016).
  10. Polanczyk, G.V. et al. “ADHD prevalence estimates across three decades: an updated systematic review and meta-regression analysis.” International Journal of Epidemiology (2014), Vol. 43, #2, 434-442.