Generalized anxiety disorder (GAD)

Mental Health, BiogeniQ, Health, TDAH

27 July 2017

Most people would agree that pretty much everyone experiences some anxiety on a daily basis. Low levels of anxiety can be beneficial as they help us respond quickly to dangerous situations. However, people who have generalized anxiety disorder (GAD) experience constant anxiety. This causes problems for those affected by the disorder and can prevent them from functioning normally in a number of everyday settings. [2]

GAD is more prevalent than you might think, with 12% of Canadian adults suffering from it, [7] most of them women. [3] Given the number of people affected, we decided to try and find out what causes this disorder.

As with most psychological disorders, while the cause is still largely unknown, experts believe there are several contributing factors, such as the person’s environment and their personality. [3] A number of possible biological causes are also currently being studied, which we will discuss below.


One of the possible causes for GAD is a health problem, such as hyperthyroidism or a respiratory disease. [3] Hyperthyroidism is a disease where an overactive thyroid gland produces too much thyroid hormone, [3] leading to increased anxiety and, in some cases, actual panic attacks. [4] Disruption of the neurotransmitters, specifically serotonin, is another possible cause. [1] As explained in previous articles, neurotransmitters are the chemical messengers that allow communication to take place in the brain. A disrupted neurotransmission system can result in all kinds of problems. When serotonin levels are affected, sleep disorders and fatigue often follow, as serotonin is the chemical responsible for regulating sleep. [5] This corresponds to commonly-experienced GAD symptoms. [3] Genetic factors are another possible cause. [2] Anxiety disorders such as GAD often occur in the same family, and having one or more parents with GAD increases the likelihood a person will develop the disorder. [6]

One thing is for sure: if you have GAD, help is available! You could talk about it with your doctor, see a therapist, or try taking medication. But, don’t wait until you can’t get out of bed or leave the house to see a professional. Don’t sweep it under the rug, as this disorder can have a huge impact on your everyday life.

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Chloé Langevin
Pharmacology Intern – BiogeniQ



  1. Brawman, O et Lydiard, RB., 1997. Biological basis of generalized anxiety disorder. J Clin Psychiatry, 58 suppl 3 :16-25 ; discussion 26. 
  1. Douglas ; Institut Universitaire en Santé Mentale, 2014. Trouble anxieux : causes et symptôme. [en ligne].
  1. Gouvernement du Québec, 2016. Troubles anxieux. [en ligne].
  1. Joffe, RT., 1993. The thyroid axis and Psychiatric Illness. American Psychiatric Pub, 256-257.
  1. McGill, 2016. Sérotonine et autres molécules impliquées dans la dépression. [en ligne].
  1. Meek, W., 2016. Causes of Generalized Anxiety Disorder. [en ligne].
  1. Townsend, Mary C, 2010. Soins infirmiers Psychiatrie et santé mental. 2e édition : ERPI, chap 20.