Maladaptive daydreaming (MD) is an increasingly recognised mental health difficulty, which refers to a compulsive cycle of dissociative absorption in vivid mental fantasy that results in clinical distress and functional impairment. Fantasies are usually complex in plot and characters, and are highly pleasurable and absorbing. MD provides temporary escape, soothing, or attempted processing of difficult internal and external experiences, but results in longer-term negative consequences that both create and exacerbate real-life suffering. The literature thus far has expanded beyond defining and understanding MD and has turned its attention towards assessment and pilot interventions. This paper presents the first formulation framework and associated diagrammatic model of MD, drawing upon the existing evidence base and cognitive behavioural theory to capture its development, maintenance, and processes. The model was reviewed by two leading experts in the field and trialled by three contributors with lived experience of MD. Feedback was positive, suggesting it accurately captured and organised the complexity and depth of the MD experience, facilitated the development of personal insight, and fostered a sense of hope with regard to creating change. The model is intended for use within clinical practice to aid mental health professionals and people with MD to guide assessment, collaborative discovery and formulation, and intervention. It is imperative that the model be tested further within research and clinical practice to further ensure its efficacy, validity, and applicability for people with MD.

1. (1) To consider the development and maintenance factors, and processes involved in MD from a cognitive behavioural perspective.

2. (2) To introduce a new formulation model for MD and understand how the model can be used in clinical practice.

3. (3) To highlight how psychological formulation has the power to better understand and organise the complex and often overwhelming MD phenomenon and provide hope for meaningful change.