Emotion, working memory, and cognitive control in patients with first-onset and previously untreated minor depressive disorders.
OBJECTIVE
To explore working memory and the ability to process different emotional stimuli in patients with first-onset and untreated minor (mild or moderate) depression.


METHODS
Patients with first-onset and previously untreated minor depression, and healthy controls, were enrolled. Using a modified Sternberg working memory paradigm to investigate the combined effects of emotional stimuli with working memory, participants were exposed to experimental stimuli comprising pictures that represented positive, neutral and negative emotions. Working memory ability was measured using reaction time and accuracy, and emotion-processing ability was measured using pupil diameter.


RESULTS
Out of 36 participants (18 patients with minor depression and 18 controls), there were no statistically significant between-group differences in response time and accuracy. Positive stimuli evoked changes in pupil diameter that were significantly smaller in patients with minor depression versus controls, but changes in pupil diameter evoked by negative stimuli were not significantly different between the two groups.


CONCLUSIONS
Healthy subjects showed a stronger emotional response to positive emotional stimuli than patients with first onset and previously untreated minor depression, but there were no differences in response to negative emotions. There were no statistically significant between-group differences in terms of speed of cognitive response, but this may have been due to the relatively small samples sizes assessed. Studies with larger sample populations are required to further investigate these results.
The International WIC Institute, Beijing University of Technology, Beijing, China The Beijing International Collaboration Base on Brain Informatics and Wisdom Services, Beijing, China The Beijing Key Laboratory of MRI and Brain Informatics, Beijing, China.
Mi
M
Li
The International WIC Institute, Beijing University of Technology, Beijing, China The Beijing International Collaboration Base on Brain Informatics and Wisdom Services, Beijing, China The Beijing Key Laboratory of MRI and Brain Informatics, Beijing, China lusf@bjut.edu.cn.
Shengfu
S
Lu
Mood Disorders Center & China Clinical Research Center for Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China Center of Depression, Beijing Institute for Brain Disorders, Beijing, China.
Gang
G
Wang
Mood Disorders Center & China Clinical Research Center for Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China Beijing Key Laboratory for Mental Disorders, Beijing, China.
Lei
L
Feng
Mood Disorders Center & China Clinical Research Center for Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China.
Bingbing
B
Fu
The International WIC Institute, Beijing University of Technology, Beijing, China The Beijing International Collaboration Base on Brain Informatics and Wisdom Services, Beijing, China The Beijing Key Laboratory of MRI and Brain Informatics, Beijing, China Department of Life Science and Informatics, Maebashi Institute of Technology, Maebashi City, Japan.
Ning
N
Zhong
D000328:Adult; D003071:Cognition; D003710:Demography; D003866:Depressive Disorder / Q000503:physiopathology*; D004644:Emotions; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D011680:Pupil / Q000502:physiology; D011930:Reaction Time
Depression; emotion; eye movement; pupil diameter; working memory