Duration of untreated illness and duration of illness in anxiety disorders: assessment and influence on outcome.

Anxiety disorders are disabling and generally chronic conditions, with a lifetime prevalence of 15-20% in the general population. These disorders are usually associated with early onset and often remain untreated for several years with important consequences on patients' functioning and quality of life. From this perspective, recent literature has considered duration of illness (DI) and duration of untreated illness (DUI), two important variables influencing outcome in many psychiatric conditions including anxiety disorders. The DUI has been defined as the interval between the onset of a specific psychiatric disorder and the subsequent administration of the first adequate pharmacological treatment given at standard dosages and for an adequate period of time in compliant subjects. The DI can be defined as the time elapsing between the onset of a psychiatric disorder and the recovery from the illness. The two variables are likely interrelated, with a longer DUI being a major contributor to a longer DI. A significant body of evidence has shown that prolonged DI and DUI are associated with structural and functional brain abnormalities as well as with poor treatment response, particularly in schizophrenia. More recently, an increasing number of studies have been pointing toward a similar conclusion in affective disorders. As a consequence, the assessment of the latency to treatment (DUI) may represent one of the first steps in order to plan early interventions and reduce the overall DI. The present chapter highlights the role of the DI and latency to treatment in anxiety disorders, focusing on epidemiologic, neuropathological, clinical and prognostic issues.