Maladaptive daydreaming, also known as excessive daydreaming, is a disordered form of dissociative absorption associated with vivid and excessive fantasy activity that often involves elaborate and fanciful scenarios. It can result in distress, can replace human interaction and may interfere with normal functioning such as social life or work. People who suffer from maladaptive daydreaming can spend more than half their days in "vivid alternative universes".
Maladaptive daydreaming is typically associated with stereotypical movements, such as pacing or rocking, and the need for musical stimulation. One of the lead researchers of maladaptive daydreaming and the person who coined the term is University of Haifa professor Eli Somer. Somer's definition of the condition is “extensive fantasy activity that replaces human interaction and/or interferes with academic, interpersonal, or vocational functioning.”