Occurrence and trajectories of psychiatric disorders in adults with gambling disorder: a longitudinal register-based study of the Finnish population

PURPOSE: To determine the co-occurrence and temporal trajectories between gambling disorder (GD) and other psychiatric diagnoses in the Finnish population. METHODS: Data were retrieved from two healthcare registers covering primary and specialized care, including 5,172 individuals aged 18 or over (3,720 males, 1,452 females) with diagnosed GD (ICD-10 code F63.0). We also retrieved information on all other psychiatric diagnosis dates (codes F00-99) between 1996 and 2024 for every individual, alongside their official sex, year of birth, and whether GD was a primary, secondary, or long-term diagnosis. Linear mixed modelling (LMM) was used to analyse longitudinal data on multiple diagnosis occurrences. RESULTS: Mood, anxiety, and substance use disorders (SUDs) had the highest co-occurrence with GD both preceding and following its diagnosis, indicating bidirectional comorbidity patterns. The most common comorbid categories included unipolar depression, phobic anxiety disorders, alcohol use disorder, and bipolar disorder. Mood disorder comorbidity was especially prominent among women, and SUD comorbidity among men. Most psychiatric diagnoses occurred 112 to 2,697 days before GD (LMM p-values 0.38 -