Measuring depression in schizophrenia with questionnaires

This paper considers the issue of the measurement of depression with those who have a primary diagnosis of schizophrenia. Originally the concept of depression as a core aspect of schizophrenia was raised by Bleuler and that affective disorders are associated with psychosis raised by Kraepelin. The construct of depression within the context of schizophrenia as a distinct condition that constitutes an apparent shift from the individual's usual cognitive style, affect and functioning, is an observation that has been relatively recently highlighted. In individuals with a primary diagnosis of schizophrenia comorbid depression can be a factor in risk of suicide, impaired level of functioning, and higher rates of relapse or rehospitalization. The assessment of depression in this population creates many challenges in relation to the differentiation of this condition within the complex presentation of schizophrenia. The depression literature may refer to: (i) depressed affect; (ii) depression as a symptom isolated from the wider signs of depressive illness; and (iii) depression as a syndrome with all the facets required for a formal diagnosis. This review considers the literature in relation to the measurement of depression in people with a primary diagnosis of schizophrenia and assesses the psychometric properties of those measures with this population.