In order to meet criteria for an episode of major depression, the youth must have experienced a two week period (at minimum) during which at least five of the following symptoms (one of which must be either depressed mood and/or loss of interest in previously enjoyable activities) are present:
- Depressed mood most of the day, nearly every day as characterized by feeling sad, empty or hopeless. In youth, this may present as primarily irritability.
- Low – or no – interest in activities that were previously enjoyable.
- Significant weight loss or gain when not actively trying to change weight – or significant changes in appetite (up or down).
- Insomnia (not able to fall or stay asleep) or hypersomnia (sleeping too much) nearly every day.
- Changes in activity – either very agitated and fidgety – or reduced/slowed movement – to the extent that other people notice.
- Fatigue or very low energy nearly every day.
- Feelings or worthlessness or excessive guilt.
- Diminished ability to concentrate or trouble making decisions that was not previously present.
- Recurrent thoughts about death or dying, including thoughts or plans about one’s own death.
In order to meet criteria for an episode of hypomania, the youth must have experienced elated or irritable mood, plus increased energy/goal-directed activity, for at least four days, in addition to at least three of the following symptoms (four if the primary mood state is irritable):
- Inflated self esteem or grandiosity
- Decreased need for sleep
- Pressured speech or fast talking
- Racing thoughts or flight of ideas
- Increased goal-directed activity
- Impulsive or reckless behavior
Importantly, these symptoms must not cause marked impairment, but should represent a change in functioning. Some youth may be naturally “hyper” or distractible; if these symptoms existed prior to the hypomanic episode, caution must be taken in attributing them to the hypomanic episode. Hypomania can be very difficult to ascertain; most youth exhibit symptoms of hypomania from time-to-time (e.g., grandiosity, high energy, pressured speech) and a few days of increased energy and more irritable or elevated mood can easily go undetected. Consequently, it is very important to carefully assess for these changes in mood and energy, particularly in youth who have depression.
Because both mood states must be observed before a diagnosis can be made, many youth will be initially misdiagnosed; this has potentially significant consequences, the treatments for depression and bipolar disorder II are quite different and some treatments for depression (i.e., SSRI antidepressants) are contraindicated for bipolar disorder.