Summary Safety Review - Selective Serotonin Reuptake Inhibitors (SSRIs) - Assessing the Potential Risk of Autism

January 6, 2017

Product

Selective serotonin reuptake inhibitors (SSRIs)

Potential Safety Issue

Autism spectrum disorders (autism)

Key Messages

• Selective Serotonin Reuptake Inhibitors (SSRIs) are prescription drugs authorized for sale in Canada to treat depression. Some are also authorized to treat anxiety disorders.
• Health Canada reviewed the risk of autism in children whose mothers used SSRIs during pregnancy, because of a published study on this topic.
• While some studies have found associations (links) between SSRI use during pregnancy and development of autism in children, others have not. Overall, Health Canada's review found that the available evidence is not strong enough to conclude that SSRI use during pregnancy can cause autism in exposed children.

Overview

Health Canada reviewed this issue because a published study found a link between SSRI exposure during pregnancy and an increased risk of autism in children. Autism is a developmental disability with lifelong impact. It affects a child's ability to communicate and interact with others.

Use in Canada

• SSRIs are prescription drugs authorized for sale in Canada to treat depression. Some are also authorized to treat anxiety disorders.
• SSRIs have been marketed in Canada for many years under the brand names Celexa (citalopram), Cipralex (escitalopram), Prozac (fluoxetine), Luvox (fluvoxamine), Paxil (paroxetine) and Zoloft (sertraline). Generic versions of all of these drugs are also available.
• During 2011, approximately 16 million SSRI prescriptions were filled in Canada. Available prescription data do not show how many SSRI prescriptions were filled by pregnant women.
• The Canadian product information for SSRIs recommends that they only be used in pregnancy if the potential benefit to the mother outweighs the potential risk to the unborn baby.

Safety Review Findings

• The literature review showed that the causes of autism are not yet well understood. Both genetics (inherited traits) and the environment that a person is exposed to in their daily life may be involved. While animal and human studies suggest that the chemical made in the body known as serotonin is important in brain development, it is hard to predict the effects of SSRI exposure on autism risk.
• Health Canada reviewed 11 studies that looked at the potential link between SSRI use during pregnancy and the development of autism in exposed children. Some studies found a link while others did not. It was difficult to draw conclusions from these studies. For example, it was difficult to separate the effects of mothers' mental illness from the effects of medications used to treat them. In other words, the links seen in certain studies may not be due to a direct effect of using SSRIs.
• At the time of the review, Health Canada had received 2 Canadian reports of autism in children after SSRI use during pregnancy.^{Footnote a} Since the causes of autism are not well understood and since there are many factors that may add to the overall risk, it was not possible to determine the role of SSRIs in the individual cases.

Conclusions and Actions

• Health Canada's review found that the available evidence is not strong enough to conclude that SSRI use during pregnancy can cause autism in exposed children.
• Health Canada will continue to monitor safety information involving SSRIs, as it does for all health products on the Canadian market, in order to identify and assess potential harms. Health Canada will take appropriate and timely action if and when any new health risks are identified.

Additional Information

The analysis that contributed to this safety review included scientific and medical literature, guidelines for managing mental illness during pregnancy, and what is known about the use of SSRIs both in Canada and internationally.

For additional information, contact the Marketed Health Products Directorate.