The comparison of cognitive tests grouped by severity of neuropsychiatric and motor symptoms. On apathy, the scores of mini–mental state examination (MMSE) (p = .019), animal verbal fluency test (VFT) (p = .038), and Stroop‐interference (p = .046) showed statistical difference among participants with no, mild, and moderate‐to‐severe symptoms. More specific, participants with no symptoms of apathy had higher performance on these tests (MMSE: p = .014; animal VFT: p = .033; Stroop‐interference: p = .036) than participants with moderate‐to‐severe symptoms (p < .05) (a). Similarity, participants with no symptoms of irritability had higher performance on Stroop‐interference (p = .005) than participants with moderate‐to‐severe symptoms (b). The scores of MMSE (p = .041) and Stroop‐interference (p = .011) showed statistical difference among participants with no, mild, and moderate‐to‐severe symptoms according to the Hamilton Depression Scale (HAMD) scores (c). There were significant difference between two groups on the scores of MMSE, total VFT, symbol digit modalities test (SDMT), Stroop reading/naming/interference, trail making test (TMT), and HVAL‐R (p < .05) (d).