VALIDITY AND REPRODUCTIBILITY OF A SCALE FOR THE EVALUATION OF DEPRESSION IN SCHIZOPHRENIC-PATIENTS

The presence of depressive symptoms in patients with schizophrenia has been recognized and described reiteratively, even though its significance on the treatment and outcome of this disorder is still ignored. The symptoms which are present in a major depressive episode are not exclusive of depression and may be confused with the negative symptoms of schizophrenia, vg, apathy, anhedonia, and abulia, or with the parkinsonian effects of antipsychotics such as akinesia. During the last few years attention has been given to the study and treatment of depression in schizophrenia, thus an appropriate clinimetrical instrument is needed. Addington et al designed a scale to assess depressive symptoms in schizophrenic patients. The behavior of such instrument in English is satisfactory; therefore, it is advaisable to translate the instrument and assess the Spanish version. We studied 103 patients with the diagnosis of schizophrenia (DSM-III-R), in two third level hospitals, who were under treatment with antipsychotics. The patients were assessed with the Calgary Scale for Depression in Schizophrenia, the Beck Depression Inventory (BDI), and the DiMascio Scale for Extrapyramidal Symptoms; besides, 50 % of the patients were also assessed with the Positive and Negative Symptom Scale for Schizophrenia (PANSS), and the remaining 50 % was evaluated with the Calgary Scale in two different days of the same week, by two independent investgators. A significant correlation was observad (r = 0.72, p < 0.0001) between the total scores of the Calgary Scale and the BDI. Neither the correlation between the Calgary scores and the DiMascio scale, nor the negative subscale of the PANSS were significant. The correlation between the scores of the Calgary Scale of the subgroup that was evaluated twice weekly was good (r = 0.80, p < 0.00001). Our findings indicate that the Calgary Scale to evaluate depression in schizophrenia has a satisfactory concurrent validity with the BDI, and its reproducibility is good. Being able to rely on this instrument will ease the study of the relationship between depressive symptoms and schizophrenia.