The parts of children’s brains that regulate emotion are still developing, and growing up certainly has its ups and downs. So, mood swings that could be indicators of a mental health condition in adults are usually perfectly normal in children. However, some children experience episodes of activity, energy and stimulation much more so than others their age, followed by extreme “down” times, when they are sullen, lethargic and sad. This can be a sign of a mental health condition called early onset bipolar disorder. This mood disorder is also called childhood manic depression, and children who have it experience mood swing so severe, that they can struggle to function in school, maintain relationships, or remain involved in extracurricular activities.