Research into the specificity of depression after stroke: A review on an unresolved issue

1. Two decades of research have failed to generate consistent insight into the specificity of poststroke depression (PSD). This is, at least in part, caused by methodological difficulties. 2. Differences in symptom profile between PSD and depression with no or ano ther medical cause were described, but no specific and unequivocal clinical picture has been established so far. 3. Prevalence rates of PSD varied largely between studies. In community bas ed studies using standardised diagnostic instruments for depression, relati vely low prevalence rates were reported compared to inpatient or rehabilita tion studies. PSD occurs most frequently in the first few months after stro ke, while a new incidence peak may occur 2-3 years after stroke. 4. Two systematic reviews on the relation between lesion location and depre ssion did not support the claim that left hemisphere lesions are a risk fac tor for PSD. A new concept of vascular depression has been proposed, which relates depression in the elderly to acute or chronic damage to the cerebra l vascular system. 5. Future efforts should aim at increasing the uniformity of study designs, assessment tools should be further improved for use in cognitively impaire d patients and appropriate control groups should be defined to study the ch aracteristic features of PSD.