Maladaptive daydreaming is a psychiatric condition first identified by Professor Eliezer Somer of the University of Haifa in Israel in 2002. This condition causes intense, vivid, and rewarding daydreaming that distracts a person from their real life. Many times, real-life events trigger daydreams. These events can include:

• a conversation
• sensory stimuli
• physical experiences

As of 2021, this condition is not in the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) and needs further research before it can be included. However, Somer has developed a 16-part diagnostic scale. The scale rates these five key characteristics of maladaptive daydreaming:

• the content and quality of the daydreams
• a person’s ability to control their dreams and compulsion to dream
• the amount of distress caused by daydreaming 
• the person’s perceived benefits of daydreaming
• how much daydreaming interferes with a person’s ability to carry out their daily activities

It is important to note that while you can use this scale to get a better idea, it is not an official diagnosis. Moreover, Maladaptive daydreaming can be misdiagnosed as schizophrenia or a dissociative identity disorder. However, the key difference is that people with Maladaptive daydreaming disorder can distinguish between reality and daydreams. They have a compulsion to return to daydreaming.

Since this condition has come to light, members of the Maladaptive Daydreaming community have invented or adopted terms to describe their daydreams, the worlds they imagine, and the characters in those daydreams. These are some terms that might help you better explain this condition to a loved one or a therapist. For a full glossary of terms related to this condition. Here is a quick list of the most used or most important terms:

• Maladaptive Daydreaming: Extensive fantasy activity replaces human interaction and/or interferes with academic, interpersonal, or vocational functioning. The condition is usually shortened to MD or MaDD for speed. 
• MDer: Someone who seems to exhibit Maladaptive Daydreaming symptoms
• Maladaptive behavior: Actions or tendencies that don't allow an individual to adjust well to certain situations. Typically disruptive and dysfunctional behaviors can range from mild to severe in scope, used to reduce mental discomfort and anxiety but are ineffective and can sometimes worsen. 
• Paracosm: A complex imaginary world, often originating in childhood.  
• Para: It is any character in a paracosm, typically with a strong attachment for the MDer.
• Paraself: The daydream version of the MDer’s self. 
• Parame: The character the MDer daydreams as; this could be a POV or the main focal point. It may also be the paraself but not necessarily. 
• Stereotypic Movement: This repetitive, nonfunctional, and motor behavior interferes explicitly with normal activities or causes bodily injury. 
• Kinesthetic Activity: Movement which stimulates or prolongs an MDer’s fantasy state. It can be Stereotypic Movement but not necessarily.