OBJECTIVES:

Obsessive-compulsive disorder (OCD) is a chronic psychiatric condition and the tenth largest cause of disability globally, with the majority of diagnosed patients experiencing moderate or severe symptoms. This study evaluated the cost-of-illness (CoI) of OCD in the UK, capturing the total annual costs accrued to the UK National Health Service (NHS), patients, informal caregivers, and wider society.

METHODS:

The UK OCD patient population was stratified by age group (children, adults, elderly), symptom severity (mild, moderate, severe) and treatment received (including no treatment). A prevalence-based approach was applied to estimate the direct and indirect costs for each subpopulation. Cost inputs were sourced from public national databases, while clinical and additional inputs were identified through targeted literature searches using UK-based studies where possible, or informed by expert clinician opinion and validated independently. Scenario analyses explored other contributory factors such as the costs associated with comorbid depression treatment and presenteeism.

RESULTS:

The base case analysis estimated a total annual CoI of OCD of £378,356,004 to the UK NHS, rising almost 10-fold to £3,095,759,464 when a societal perspective was considered. The annual cost of care per OCD patient increased with severity (mild: £174; moderate: £365; severe: £902) due to increasing first-line and second-line healthcare resource utilisation. The largest contributor to healthcare costs was cognitive behavioural therapy, while societal costs were driven by lost productivity through absenteeism. The base case results likely underestimated the true economic burden of OCD; scenario analyses showed that including comorbid depression led to a 132% increase in direct treatment costs, while presenteeism in patients and lost productivity in informal caregivers amplified indirect costs.

CONCLUSIONS:

The economic burden of OCD in the UK is substantial and extends beyond direct treatment costs, reflecting a need for further research into alternative treatments with greater efficacy, to reduce the clinical and humanistic disease impact and resulting CoI.