What sort of problem is an adjustment disorder?

Behavioral/cognitive: I will refer this to experts in behavioral medicine, psychology, psychiatry. Thanks for asking this important question.

Reaction to problems: Adjustment disorder refers to problems with mood, behavior, or both, that arise directly because of an identifiable situation. For example, a child might abruptly become sad, withdrawn, and oppositional upon hearing that her parents are getting a divorce. Although it can be chronic, it usually has a clear beginning and may resolve if conditions change.