Chemosensory anhedonia facilitates depressive symptoms and cognitive impairment in late-life depression.

AIM

Chemosensory anhedonia refers to the lack of hedonic ability to experience pleasure through the senses of smell and taste, which reduces the pleasure and comfort of food, and increases the risk of nutritional and immune deficiencies. However, there is no direct scientific evidence regarding chemosensory anhedonia in patients with late-life depression (LLD). The aim of this study was to investigate chemosensory anhedonia in patients with LLD, and its potential association with depressive symptoms and cognitive function.

METHODS

A total of 114 patients with LLD and 92 normal controls were included in this study. They experienced clinical assessment, Chemosensory Pleasure Scale assessment, 17-item Hamilton Depression Rating Scale assessment and cognitive assessments, which contain the Verbal Fluency Test. The associations between chemosensory pleasure and depressive symptoms or cognitive function in patients with LLD were explored using partial correlation analysis and mediation analysis.

RESULTS

The Chemosensory Pleasure Scale scores were lower in the LLD group than in the normal control group, and were negatively correlated with the total scores and factors' scores (retardation, cognitive bias and anxiety/somatization) of the 17-item Hamilton Depression Rating Scale, and positively correlated with the Verbal Fluency Test scores. The scores for the Food and Imagination dimensions of the Chemosensory Pleasure Scale showed partial mediating effects on the differences in Cognitive bias (a factor of the 17-item Hamilton Depression Rating Scale) between patients with LLD and normal controls.

CONCLUSIONS

Patients with LLD showed significant chemosensory anhedonia, and both depressive symptoms and cognitive impairment were associated with the severity of chemosensory anhedonia. Enhancing chemosensory pleasure in patients with LLD could potentially ameliorate their depressive symptoms. Geriatr Gerontol Int 2024; 24: 1022-1029.