The mechanisms underlying post-stroke depression (PSD), a common and debilitating complication of stroke, remain unclear. Is it neurobiological, psychosocial, or a combination of both?
Two studies offer new insights into this question. In the first study, researchers systematically reviewed studies comparing post-stroke and non-stroke participants with depression and found that the groups were similar in most dimensions of depressive symptoms. However, patients with PSD exhibited more severe emotional dysregulation and less anhedonia compared to non-stroke control groups.
„Our findings support previous recommendations that doctors should tailor the provision of psychological support to the specific needs and struggles of stroke survivors,“ said lead author Joshua Blake, DClinPsy, Lecturer in Clinical Psychology at the University of East Anglia, Norwich, UK. The study was published online on September 5, 2023, in the Neuropsychology Review.
In a second study, researchers analyzed blood samples from adults who had suffered a stroke using a machine learning algorithm to predict mood and identify potential proteins related to the mood of these patients. „We can now look at a stroke survivor’s blood and predict their mood,“ said lead author Marion Buckwalter, MD, PhD, Professor of Neurology and Neurosurgery at Stanford Medicine, California. „This means that there is a real connection between what’s happening in the blood and what’s happening with a person’s mood. It also means that we may be able to develop new treatment methods for PSD in the future.“ The study was published in Brain, Behavior, and Immunity in November 2023.
Blake stated that the study addressed the uncertainty about whether PSD could be different from non-stroke depression due to the presence of brain injury, associated biological changes, and the specific psychosocial context of this population. The findings revealed primarily non-significant differences between patients with PSD and non-stroke control groups in most dimensions of depressive symptoms. However, the researchers observed a greater severity/prevalence of emotional dysregulation in PSD and less anhedonia.
Initially, the researchers were surprised by these findings. They suggested that the emotional journey of recovery after a stroke, combined with possible neurologically induced emotional dysregulation, may protect against anhedonia in stroke survivors.
Buckwalter highlighted the need for more research on PSD, as it is one of the most common problems reported by chronic stroke patients but remains largely untreated.
The proteomic approach used in the second study showed a link between plasma protein measurements and mood in chronic stroke patients. The findings identified changes in plasma protein levels related to depression after a stroke, suggesting potential new therapeutic targets for PSD beyond selective serotonin reuptake inhibitors.
Overall, both studies complement previous research on PSD and offer potential new insights into the neurobiological and psychosocial factors contributing to the condition. However, caution should be exercised in interpreting the results due to methodological limitations and the need for further research with larger and more diverse cohorts.