BACKGROUND: Poststroke depression (PSD) is a common and invalidating condition, 
requiring a prompt diagnosis to provide appropriate treatment. The diagnosis of 
PSD is based on clinical evaluation, supported by psychiatric scales, 
predominantly constructed to assess 'functional' depressive disorders, which can 
miss important clinical information about PSD. This study evaluated the 
diagnostic accuracy of the Poststroke Depression Rating Scale (PSDRS), a 
diagnostic tool specifically devised to assess depression after stroke, in 
comparison to the Hamilton Depression Rating Scale (Ham-D).
METHODS: 143 patients were enrolled at their first-ever stroke; 46 subjects 
received a diagnosis of major depression-like disorder (MDL) and 53 a diagnosis 
of mood disorder with depressive manifestations (MDDM). Each patient underwent 
the PSDRS, Ham-D and Mini Mental State Examination. Areas under 
receiver-operating characteristic curves were calculated to evaluate diagnostic 
accuracy.
RESULTS: At their optimum cut-off points, the Ham-D and PSDRS showed good 
sensitivity and specificity for MDL or MDL + MDDM; the PSDRS had a higher 
positive predictive value for MDL in respect of the Ham-D (78 vs. 59%). 
Furthermore, the diagnostic accuracy of the PSDRS was higher in respect of the 
Ham-D in aphasic patients. Regression analyses showed that a longer latency from 
stroke onset predicted misdiagnosis on both PSDRS and Ham-D; the Ham-D was 
significantly influenced by cognitive impairment while the PSDRS was affected by 
age.
CONCLUSIONS: The Ham-D and PSDRS are both reliable diagnostic tools for the 
diagnosis of PSD. The PSDRS showed a slightly superior positive predictive value 
for MDL, particularly in aphasic patients, and was not influenced by cognitive 
dysfunction, a common consequence of stroke affecting the diagnostic performance 
of the Ham-D. We suggest that the PSDRS could be a useful tool in clinical 
practice and in therapeutic trials.