From the Journals

Resting-state cerebral blood flow tied to apathy in schizophrenia



Regional resting-state cerebral blood flow (rCBF) in the ventral and dorsal striatum is associated with apathy in patients with schizophrenia – but not with diminished expression, results of a small study suggest.

“This distinction is of high relevance when investigating striatal rCBF,” wrote Karoline Schneider, MD, and colleagues. “The paucity of reported associations beween striatal rCBF and negative symptoms could result from the fact that until now apathy and diminished expression have not been addressed separately.” The study was published in the Journal of Psychiatry & Neuroscience.

Dr. Schneider and colleagues used arterial spin labeling MRI to measure rCBF in 29 patients with schizophrenia from outpatient and inpatient units affiliated with the University of Zürich and in 20 controls without schizophrenia. Negative symptoms were assessed via the Brief Negative Symptom Scale and were divided into those of apathy or those of diminished expression.

Significant correlations were found between severity of apathy symptoms and higher rCBF in the left and right ventral striatum was (r = 0.38; P = .04), and between severity and higher rCBF in the left and right dorsal striatum (r = 0.48; P = .008). However, the correlations were nonsignificant for symptoms of diminished expression, reported Dr. Schneider, of the university’s department of psychiatry, psychotherapy, and psychosomatics.

“The association between increased striatal rCBF and the negative symptom dimension of apathy, but not diminished expression, provides further evidence for the assumption of different underlying neural bases,” Dr. Schneider and colleagues concluded. “These dimensions should be considered separately in future research on negative symptoms.”

Limitations of the study include its sample size. Another limitation is that all patients with schizophrenia in the study were taking second-generation antipsychotics, which in some research appears to influence striatal rCBF.

Grants from the Swiss National Science Foundation funded the study. Dr. Schneider reported no conflicts of interest. Two authors disclosed receiving grant support or honoraria from pharmaceutical companies but said those activities were unrelated to this study.

SOURCE: Schneider K et al. J Psychiatry Neurosci. 2019;44(2):102-10.

Next Article: