“In the FDA review, no completed suicides occurred among nearly 2,200 children treated with SSRI medications. However, about 4 percent of those taking SSRI medications experienced suicidal thinking or behavior, including actual suicide attempts—twice the rate of those taking placebo, or sugar pills.
In response, the FDA adopted a “black box” label warning indicating that antidepressants may increase the risk of suicidal thinking and behavior in some children and adolescents with MDD. A black-box warning is the most serious type of warning in prescription drug labeling.
The warning also notes that children and adolescents taking SSRI medications should be closely monitored for any worsening in depression, emergence of suicidal thinking or behavior, or unusual changes in behavior, such as sleeplessness, agitation, or withdrawal from normal social situations. Close monitoring is especially important during the first four weeks of treatment. SSRI medications usually have few side effects in children and adolescents, but for unknown reasons, they may trigger agitation and abnormal behavior in certain individuals.”
Source
https://www.nimh.nih.gov/health/topics/child-and-adolescent-mental-health/antidepressant-medications-for-children-and-adolescents-information-for-parents-and-caregivers.shtml, Last Accessed 4/2/2018