Cross-cultural adaptation and validation of the Spanish version of the Calgary Depression Scale for Schizophrenia.
BACKGROUND
The Calgary Depression Scale for Schizophrenia (CDSS) is a valid tool to assess depression in schizophrenics and has been translated, adapted, and validated to be used in different non-English languages. Therefore, it may be predicted that a Spanish version of this scale will be also a valid instrument to assess symptoms of depression in patients with schizophrenia.


OBJECTIVE
We determined the validity of the Spanish version of the Calgary scale (CDSS-S).


METHODS
Outpatients and inpatients (n=93) diagnosed as having schizophrenia by DSM-IV criteria confirmed by SCID-IV interview were included. The Positive and Negative Syndrome Scale (PANSS), Hamilton Depression Rating Scale (HDRS-17 and HDRS-21 items), Montgomery-Asberg Depression Rating Scale (MADRS), Extrapyramidal Symptoms Rating Scale (ESRS), and Barnes Acathisia Rating Scale were administered by a first rater, whereas the CDSS-S was assessed by a second independent rater.


RESULTS
The internal consistency (Cronbach's alpha 0.83) and the interrater reliability (>0.73 intraclass correlation coefficient [ICC] for single items and 0.92 for total score) were good. The test-retest reliability was high (ICC of 0.89). The scale showed a good construct validity with statistically significant correlations with HDRS-17, HDRS-21, MADRS, and G6 item (depression) of PANSS. The CDSS showed no correlation with the positive subscale of PANSS and a weak correlation with the negative subscale, general psychopathology subscale, and total score of PANSS. A cut point of five showed 94.7% sensitivity, 86.5% specificity, and 70% and 98% positive and negative predictive values, respectively.


CONCLUSIONS
The Spanish version of CDSS is a valid instrument to assess depressive episodes for stabilized and acute patients with schizophrenia.
Sarró
Salvador
S
Department of Psychiatry, Hospital General de Granollers, Avda. Francesc Ribas s/n, E-08400, Granollers, Barcelona, Spain. 27765ssm@comb.es
Dueñas
Rosa M
RM
Ramírez
Nicolás
N
Arranz
Belén
B
Martínez
Ramón
R
Sánchez
José M
JM
González
José M
JM
Saló
Laura
L
Miralles
Luisa
L
San
Luis
L
D000328:Adult; D015897:Comorbidity; D003431:Cross-Cultural Comparison; D003866:Depressive Disorder / Q000175:diagnosis* / Q000208:ethnology / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D011594:Psychometrics; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis* / Q000208:ethnology; D012565:Schizophrenic Psychology; D013030:Spain / Q000208:ethnology; D014177:Translations; D014481:United States