Ritalin, Adderall and all other drugs used to treat attention deficit hyperactivity disorder have the potential to cause uncommon psychiatric side-effects including rare cases of agitation and hallucination in children, Health Canada warned Thursday.

The department announced all drugs used to manage ADHD will carry new labels in December. Prescribing information will also be updated, based on an ongoing review of psychiatric events linked to the drug.

Health Canada says even though the side effects are rare it felt compelled to issue a warning.

"The message is every drug has benefits and risks associated with that," said Dr. Duc Vu of Health Canada. "ADHD is the condition that needs to be treated and needs to be monitored.

Two million prescriptions for the stimulants, which increase blood pressure and speed up the pulse, were written in Canada in 2005, and use of the drugs is increasing.

The psychiatric warning follows the department's alert earlier this year on rare heart-related risks for all ADHD drugs.

Canadian adults and children were advised not to use the drugs if they have high blood pressure, heart disease or other heart problems, hardening of the arteries or an overactive thyroid gland. Drug labels were standardized to report the risk of rare heart-related side-effects.

That warning came after 25 deaths linked to the drugs occurred in the U.S. Some of those who died were children.

Dr. Wendy Roberts, who has been prescribing these drugs for decades, told CBC that the warning shouldn't cause parents to panic.

"If you get an unusual effect, and you always need to talk about it and monitor for it, you stop the drug and it goes away," said Roberts. "In the majority of children this is just not an issue, it's a very small number that we're talking about."

Patients should check with a doctor about taking the drugs or if they have questions or concerns.

Health Canada's safety review of ADHD drugs including Adderall XR, Attenade, Biphentin, Concerta, Dexedrine, Ritalin, Ritalin SR and Strattera continues.