表題番号：2023C-523
日付：2024/03/28
研究課題行動活性化療法の作用機序に対するアンヘドニアを考慮した記述的検討
| 研究者所属（当時） | 資格 | 氏名 | |
|---|---|---|---|
| （代表者） | 人間科学学術院 人間科学部 | 教授 | 嶋田 洋徳 |
| （連携研究者） | 大学院人間科学研究科 | 大学院生 | 石川 律 |
- 研究成果概要
- Although behavioral activation therapy is effective against depression, it is ineffective for individuals with high levels of anhedonia (loss of the ability to enjoy things or activities), a core symptom of depression (Alsayednasser et al., 2022). Since salivary cortisol impairs information processing, it is likely that anhedonia is regulated by salivary cortisol. Therefore, this study aimed to examine the relationship between anhedonia and salivary cortisol in individuals receiving behavioral activation therapy.
The study participants were 30 undergraduate and graduate students (mean age 23.6 ± 3.1 years) from a private university. Data were analyzed using indices of anhedonia, behavioral activation, reward perception, depression, and response area and response volume for salivary cortisol concentration. Results indicated that the response area of salivary cortisol concentration was independent of anhedonia status (R^2 = .004, p = .782). Moreover, we could not confirm the mediation of salivary cortisol in the relationship between reward perception and depression (z = .079, p = .937). The high response group (n = 11) was defined as those with a response volume for salivary cortisol concentration greater than the median, and the low response group (n = 11) was defined as those with a response volume less than the median. A significant moderate negative correlation was found between anhedonia and reward perception in the high response group (r = −.674, p = .023), but a significant strong negative correlation was found between anhedonia and perceived reward in the low response group (r = −.791, p = .004). Furthermore, we could not confirm that reward perception mediated the relationship between behavioral activation and depression in the high response group (z = .300, p = .765). However, in the low response group, reward perception mediated the relationship between behavioral activation therapy and depression (z = −2.503, p = .012).
The study results suggest that changes in reward perception have a direct effect on depression, but not via psychophysiological changes. In addition, salivary cortisol moderated the association between anhedonia and behavioral activation therapy variables, which could be interpreted as an indirect effect of salivary cortisol on anhedonia; this finding warrants further investigation.