What are the stages of severity in maladaptive dreaming?

Maladaptive daydreaming, first described in 2002, is not yet included in the DSM despite efforts for its inclusion. The severity in a given individual would first depend on whether their daydreams are maladaptive and, if so, to what degree they interfere with a healthy, productive life. You've been asking for more than this forum can answer. Try https://maladaptivedaydreaming.org/