Major Depressive Disorder Among Preadolescent Canadian Children: Rare Disorder or Rarely Detected?

Despite agreement that preadult onset of depression is associated with greater illness severity, and that children can meet the diagnostic criteria for major depressive disorder (MDD), few studies have examined the presentation of MDD among young children. This is the first nationwide study of MDD among preadolescent children in Canada.

Pediatrician members (2500) of a Canadian pediatric surveillance network were surveyed monthly over 3 years to report new cases of MDD among 5- to 12-year-olds. Survey response and questionnaire completion rates were 80% and 85%, respectively. Symptom presentation and duration, impairment, medical and psychiatric history, and management were reported.

Twenty-nine new cases of MDD were identified by pediatricians. Of these, 23 (79%) experienced symptoms for >6 months before presentation with global functional impairment. Parental depression or anxiety, commonly maternal, was present in 21 cases (72%). Twenty-two children (76%) reported suicidal ideation; 6 (21%) had attempted suicide. Twenty-three children (79%) were treated with medication. Thirteen children (45%) were treated with 2 or more medications.

Children with MDD frequently had a parental history of mood disorders, experienced long-standing symptom presence, high symptom burden and functional impairment prior to presentation; and commonly treatment with polypharmacy.