Evaluating depressive symptoms in schizophrenia: a psychometric comparison of the Calgary Depression Scale for Schizophrenia and the Hamilton Depression Rating Scale.
BACKGROUND
The aim of this study was to compare two measures of depression in patients with schizophrenia and schizophrenia spectrum disorder, including patients with delusional and schizoaffective disorder, to conclude implications for their application.


METHODS
A total of 278 patients were assessed using the Calgary Depression Scale for Schizophrenia (CDSS) and the Hamilton Depression Rating Scale (HAMD-17). The Positive and Negative Syndrome Scale (PANSS) was also applied. At admission and discharge, a principal component analysis was performed with each depression scale. The two depression rating scales were furthermore compared using correlation and regression analyses.


RESULTS
Three factors were revealed for the CDSS and HAMD-17 factor component analysis. A very similar item loading was found for the CDSS at admission and discharge, whereas results of the loadings of the HAMD-17 items were less stable. The first two factors of the CDSS revealed correlations with positive, negative and general psychopathology. In contrast, multiple significant correlations were found for the HAMD-17 factors and the PANSS subscores. Multiple regression analyses demonstrated that the HAMD-17 accounted more for the positive and negative symptom domains than the CDSS.


CONCLUSIONS
The present results suggest that compared to the HAMD-17, the CDSS is a more specific instrument to measure depressive symptoms in schizophrenia and schizophrenia spectrum disorder, especially in acutely ill patients.
Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Munich, Germany. Rebecca.Schennach@med.uni-muenchen.de
Rebecca
R
Schennach
Michael
M
Obermeier
Florian
F
Seemüller
Markus
M
Jäger
Max
M
Schmauss
Gerd
G
Laux
Herbert
H
Pfeiffer
Dieter
D
Naber
Lutz G
LG
Schmidt
Wolfgang
W
Gaebel
Joachim
J
Klosterkötter
Isabella
I
Heuser
Wolfgang
W
Maier
Matthias R
MR
Lemke
Eckart
E
Rüther
Stefan
S
Klingberg
Markus
M
Gastpar
Michael
M
Riedel
Hans-Jürgen
HJ
Möller
D000293:Adolescent; D000328:Adult; D000368:Aged; D003863:Depression / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D003866:Depressive Disorder / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D012559:Schizophrenia / Q000150:complications*; D012565:Schizophrenic Psychology