Impact of severity and type of depression on quality of life in cases identified in the community

• Published in: Psychological medicine Vol. 40; no. 12; pp. 2069 - 2077
• Main Authors: Nuevo, R., Leighton, C., Dunn, G., Dowrick, C., Lehtinen, V., Dalgard, O. S., Casey, P., Vázquez-Barquero, J. L., Ayuso-Mateos, J. L.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.12.2010
• Subjects: Adult; Adult and adolescent clinical studies; Biological and medical sciences; Case-Control Studies; Classification; Community; Depression; Depression - physiopathology; Depression - psychology; Depressive episode; disability; Disabled Persons - psychology; Female; Health Status; Health Surveys; Humans; Male; Medical sciences; Mental depression; Mental Health; Middle Aged; Mood disorders; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Quality of Life; Severity; Severity of Illness Index; SF-36; Short forms; severity; Depressive episode; quality of life; disability; SF-36; Mood disorder; Social environment; Handicap; Human; Multicenter study; Mental health; Depression; Nosology; Epidemiology; Quality of life; Disability; Criterion; International Classification of Diseases 10; Classification; Severity score; Diagnosis; Predictive factor; Public health; International
• ISSN: 0033-2917; 1469-8978
• DOI: 10.1017/S0033291710000164

The impact of different levels of depression severity on quality of life (QoL) is not well studied, particularly regarding ICD-10 criteria. The ICD classification of depressive episodes in three levels of severity is also controversial and the less severe category, mild, has been considered as unnecessary and not clearly distinguishable from non-clinical states. The present work aimed to test the relationship between depression severity according to ICD-10 criteria and several dimensions of functioning as assessed by Medical Outcome Study (MOS) 36-item Short Form general health survey (SF-36) at the population level. A sample of 551 participants from the second phase of the Outcome of Depression International Network (ODIN) study (228 controls without depression and 313 persons fulfilling ICD criteria for depressive episode) was selected for a further assessment of several variables, including QoL related to physical and mental health as measured with the SF-36. Statistically significant differences between controls and the depression group were found in both physical and mental markers of health, regardless of the level of depression severity; however, there were very few differences in QoL between levels of depression as defined by ICD-10. Regardless of the presence of depression, disability, widowed status, being a woman and older age were associated with worse QoL in a structural equation analysis with covariates. Likewise, there were no differences according to the type of depression (single-episode versus recurrent). These results cast doubt on the adequacy of the current ICD classification of depression in three levels of severity.