ICD-10 or DSM-IV? Anhedonia, fatigue and depressed mood as screening symptoms for diagnosing a current depressive episode in physically ill patients in general hospital.

Objective: To explore the usefulness of "anhedonia", "fatigue" and "depressed mood" as screening symptoms for predicting a depressive episode in physically ill patients.

Method: 290 patients filled in a modified version of the Patient Questionnaire and were subsequently assessed by psychiatrists with the Composite International Diagnostic Interview (CIDI; ICD-10 version).

Results: 63 patients suffered from a current depressive episode according to the CIDI. If at least two of the three symptoms were used for screening positively (ICD-10 algorithm), the sensitivity was 93.2% and the specificity 72.7%, while the simpler algorithm of DSM-IV - requiring depressed mood or anhedonia to be present - yielded a slightly higher sensitivity (95.2%) and a slightly lower specificity (66.5%). One in five patients with a depressive episode did not report "depressed mood".

Limitation: It remains unclear how relevant the three core symptoms of depression are for the diagnosis of an ICD-10 depression in people who are not physically ill.

Conclusion: The fact that both diagnostic algorithms yielded comparable results suggests that the more parsimonious DSM-IV algorithm is preferable and "fatigue" could be left out as a screening symptom. Since "depressed mood" was absent in a substantial proportion of patients, special attention has to be paid to "anhedonia". Medical students and non-psychiatric clinicians should be especially trained to ask for anhedonia, so that cases of depression will not be overlooked.