The government plans to strengthen warnings about possible psychiatric side effects from Concerta, after a routine FDA review turned up reports of unexpected psychiatric reactions, including suicidal thoughts and violent behavior.

Concerta is a long-acting form of methylphenidate, used to treat attention deficit hyperactivity (ADHD). It is also found in Ritalin. For years, these drugs have carried labels warning of possible side effects including, agitation, psychosis or transient depression.

FDA drug safety evaluator, Kathleen Phelan, says the drugs current labels tend to downplay the seriousness of said side effects and imply that only those with previous psychiatric disorders are prone to them.

Among 36 cases of psychiatric side effects in children using Concerta, only six reported histories of psychiatric illness, three denied such histories, and no information was obtained on the rest.

Further investigation is pertinent to determining whether side effects can occur in people without past psychiatric episodes.

The FDA will conduct investigations on other ADHD treatments like Adderall and Strattera, before changing the drugs' labels. The probe is expected to be completed by early next year.