Where Dysthymia Ends and Depression Begins
Something else to remember is that dysthymia can in fact coexist with major depression. After the initial period of time (one year) necessary to make a diagnosis of dysthymia, a child can then develop major depression. This is sometimes referred to as double depression. So it makes sense to get your child evaluated sooner than later.
As a child reaches puberty and adolescence, it is easy to discount a child's moods as being hormonal. Sometimes the imbalance and surge of hormones that your child experiences during this time can actually exacerbate or even cause dysthymia or depression. Since puberty can last as long as a dysthymic episode, the distinctions become even cloudier.
Forget the Label
Trying to label your child as depressed or dysthymic should not be your focus. Both disorders are debilitating in different ways, and both will cause major disruptions in your child's academic, social, and, if older, occupational functioning. The focus needs to be on seeing the symptoms and seeking help to determine if they are just moods or something more serious.