Depression is one of the most common medical illnesses in America. Two of the primary forms of depression are Major Depressive Disorder (MDD) and Persistent Depressive Disorder (PDD).

Children and adolescents with MDD experience a depressed mood or a loss of interest or pleasure in daily activities lasting for at least a two week period. During this period, the depressed mood must be present most of the day, nearly every day. So, feeling down or blue for a day or two is a normal experience, and is not depression. Importantly, sometimes in children and adolescents depression is expressed through irritability and anger, and may not look like sadness. Individuals with MDD may notice a marked difference in their current mood compared to their normal mood, or mood prior to the depressive episode.

Many of the features of MDD and PDD are similar, with the biggest differences reflecting the intensity and duration of the symptoms. A child diagnosed with PDD has typically been struggling with a low mood and feelings of sadness and irritability more days than not, over an entire year. The feelings may not be as intense as during MDD, but they last for a much longer period of time.

A depressed mood caused by either substances (such as drugs, alcohol, or medications) or a general medical condition is not considered depression. Furthermore, a period of sadness resulting from the loss of a loved one would not be considered MDD or PDD.


  • Diminished interest or pleasure in regularly enjoyable activities
  • Depressed or irritable mood
  • Significant change in appetite or weight or failure to meet developmental weight gains
  • Changes in sleeping habits
  • Inability to think or make┬ádecisions
  • Tiredness or loss of energy
  • Feelings of worthlessness and/or┬áhopelessness
  • Thoughts of suicide