Crises, power struggles and negotiation are all too well-known for parents who have a child with oppositional defiant disorder (ODD). However, for those who are not familiar with this disorder: what exactly is it?
ODD is reported to affect between 1% and 16% of children. [4, 5] Often associated with attention deficit disorder with or without hyperactivity (AD / HD), ODD is characterized by uncooperative, defiant and hostile behaviour by children towards the adults responsible for them or their peers.  While the exact cause of ODD is unknown, it is believed that a combination of psychological, environmental and neurological factors may contribute to the condition.  And yes, once again, science can help us better understand this phenomenon.
There appear to be three neurological causes for ODD. The first is associated with abnormalities or injury to certain areas of the brain, specifically the prefrontal lobe. [1, 6] This brain region is involved in attention, personality expression and moderating social behaviour.  A defect in this part of the brain affects emotional control and is therefore directly related to ODD symptoms. The second cause is related to a problem with the brain’s neurotransmitters.  Neurotransmitters enable brain cells to communicate with each other. If these chemical messengers become unbalanced, the child may experience ODD-related symptoms such as anxiety and mood swings.  The last cause is genetic.  In the family of children with ODD, it is common to see someone who has a history of anxiety and / or mood disorders. 
It is important to remember that ODD is most likely caused by a combination of factors. Also, we must not confuse oppositional disorder with other disorders such as behavioural disorder and AD / HD as they present quite differently. For example, when faced with the same situation, a child with ODD would get angry, a child with behavioural disorder would threaten and bully and a child with ADHD would show a complete lack of interest. 
Many children with ODD also suffer from other disorders such as ADHD, learning difficulties or anxiety disorders, and these additional challenges can exacerbate their ODD. [2, 6] However, all is not lost; there are many resources out there for children with this disorder, among them Naître et grandir (in French only).  Help is available; it’s up to you to take the first step.
Pharmacology Intern – BiogeniQ
- AACAP official action. Practice parameter for the assessment and treatment of children and adolescents with oppositional defiant disorder. Am. Acad. Child Adolesc. Psychiatry, 2007;46(1):126Y141.
- AACAP official action. Children with oppositional defiant disorder. Facts for Families. 2011 ; 72 :3-11
- Bedkowska, B. Le trouble oppositionnel avec provocation : recension des écrits et programme de prévention. Université de Sherbrooke. 2007 :1-53
- Loeber, R, Burke, JD, Lahey, BB, Winters, A, Zera, M.Oppositional defiant and conduct disorder: a review of the past 10 years, part I. Am Acad Child Adolesc Psychiatry. 2000;39:1468–1484.
- Riley, M, Ahmed, S, Locke, A. Common question about oppositional defiant disorder. American family physician. 2016 ;93 : 586-591
- Cleveland Clinic. Oppositional defiant disorder. 2014 [en ligne] https://my.clevelandclinic.org/health/articles/oppositional-defiant-disorder.
- Audesirk, T., Audesirk, G., & Byers, B. E. (2008). Biology: Life on earth with physiology. Upper Saddle River, NJ: Pearson Prentice Hall.
- Sanfaçon, C. Il n’est pas comme les autres !: Les comportements d’opposition. http://cqjdc.org/wp/wp-content/uploads/2014/10/Il-n_etait-pas-comme-les-autres.pdf
- Naitre et grandir. Le trouble de l’opposion. 2015 [en ligne] http://naitreetgrandir.com/fr/etape/1_3_ans/comportement/fiche.aspx?doc=trouble-opposition.