Research diagnosis of current depressive disorder: A comparison of methods using current symptoms and lifetime history

Data from the WHO international study of Psychological Problems in General Health Care were used to compare two alternative algorithms for diagnosing current major depression using the Composite International Diagnostic Interview: the traditional method based on lifetime diagnosis and an alternative method based on number of current symptoms. Using DSM-IV criteria for current major depression, 6.2% of 5394 primary care patients were diagnosed by both methods, 2.0% by the lifetime-based method only, and 1.9% by the current symptom method only. Measures of severity (current symptoms, lifetime symptoms, disability, and comorbid anxiety) indicated that those diagnosed by only one method were only slightly less ill than those diagnosed by both. While the symptom-based method identifies a slightly more ill group, use of either method alone may exclude many who differ little from those classified as cases.