Which is the optimal depression rating scale to identify DSM-IV depression in schizophrenia ? a diagnostic validity comparison of five mood scales

Abstract EN

-bjectives: To find a brief semi-structured or self-report depression rating scale with the highest accuracy for a diagnosis of DSM-IV defined depression in patients with schizophrenia from Iraqi-Kurdistan.

Methods: 200 people with schizophrenia living in the Kurdistan Region of Iraq were recruited.

The Mini International Neuropsychiatric Interview (MINI) was used to define the presence of schizophrenia; depression was further defined according to DSM-IV criteria.

Symptoms of depression were examined using five scales: the Patient Health Questionnaire (PHQ2, PHQ9), Hospital Anxiety and Depression Scale (HADS), the Centre for Epidemiological Studies Depression scale (CES-D) and the Calgary Depression Scale for Schizophrenia (CDSS).

Three psychiatrists conducted interviews and rated the Clinical Global Impression (CGI).

ROC curve analysis was used to establish the optimal cut-off as well as comparative sensitivity and specificity.

Results: Eighty (40%) patients had DSM-IV major depression and 97 (48.5%) had major or minor depression; 157 (78.5%) had at least two DSM-IV symptoms of depression.

Comparing the five scales for identification of depression showed the optimal methods for detection of major depression (against non-major depression) were the PHQ9 > PHQ2 > CDSS.

Against major depression the PHQ9 was the most accurate method with a sensitivity of 93.8% and a specificity of 84.2%.

Optimal methods for detection of major or minor depression (against no depression) were the PHQ2 > PHQ9 > CDSS.

The PHQ2 had a sensitivity of 85.6% and a specificity of 96.1%.

Conclusion: Self-report scales, particularly the PHQ2 and PHQ9 appear to perform well against DSM-IV defined depression in schizophrenia.

Further validation against non-DSM-IV standards is recommended.