Body dysmorphic disorder (BDD) is characterised by excessive preoccupation with perceived flaws in physical appearance (most commonly facial features), which appear minimal or completely unobservable to others. Sufferers typically engage in a range of compulsive and repetitive behaviours, such as extreme grooming rituals, often in an attempt to conceal or correct their perceived appearance flaws. The disorder usually starts during adolescence, with an average onset at age 16. BDD affects about 2% of the general population at any one point in time, although up to 15% experience subthreshold symptoms that are impairing in their own right. The disorder has a devasting impact on quality of life, and is linked with high risk of suicidality. Is it estimated that one in four people with BDD attempt suicide, making it one of the most high-risk of all psychiatry disorders. Despite the prevalence and morbidity of BDD, it remains strikingly under-researched.

There is currently a lack of clarity about how BDD relates to other mental health disorders. BDD was previously classed as a “somatoform disorder”, but was recently reclassified under “obsessive-compulsive and related disorders” in the major diagnostic systems (DSM-5 and ICD-11). This classification remains a focus of debate. For example, data from recent cross-sectional studies have indicated BDD has stronger links with eating disorders and depression than obsessive-compulsive disorder. However, the longitudinal associations of other psychiatric disorders with BDD remain unclear. This study therefore aims to determine the extent to which different psychiatric symptoms during adolescence predict body dysmorphic symptoms in adulthood.