Plasma and cerebrospinal fluid substance P in post-stroke patients with depression

Aims: To investigate the correlation between the incidence of post‐stroke depression (PSD) and the levels of substance P (SP) in the plasma and cerebrospinal fluid (CSF). Methods: Ninety‐one stroke patients were divided into PSD (n = 46) and post‐stroke (without depression) groups (n = 45). PSD must have occurred 2–4 weeks after the onset of the stroke and was determined by the Hamilton Rating Scale for Depression (HAMD). In addition, the subjects were divided into anterior (n = 67) and posterior circulation stroke groups (n = 24) based on the location of the focus as determined by computed tomography. All recruited patients were graded by the National Institutes of Health Stroke Scale (NIHSS). Results: The results included the following findings: (i) the level of plasma SP in the PSD group (58.47 ± 14.39) was higher than that of the PS group (36.98 ± 9.49; P = 0.000), while the level of CSF SP in the PSD group (72.13 ± 13.06) was higher than that of the post‐stroke group (37.30 ± 12.57; P = 0.03); (ii) the level of plasma SP was positively correlated with the HAMD and NIHSS score; (iii) the level of plasma SP (38.45 ± 12.23), the HAMD score (9.08 ± 8.72), and the NIHSS score (3.25 ± 1.90) of the anterior stroke group (51.21 ± 16.27, 17.46 ± 15.96, and 6.91 ± 3.30, respectively) were higher than those of the posterior stroke group (38.45 ± 12.23, 9.08 ± 8.7, and 3.25 ± 1.90, respectively; P = 0.017, P = 0.001, and P = 0.000, respectively). Conclusions: SP in the plasma and CSF of patients exhibited a close correlation with neural damage and the incidence of PSD. This study also suggested that anterior hemispheric strokes may play a significant role in development of PSD.