University of Illinois at Chicago (UIC) College of Medicine researchers have found that the dorsal anterior cingulate cortex (DACC) may have to work harder to modify negative emotional responses in people with poor sleep who have depression or anxiety.

Heide Klumpp, PhD, assistant professor of psychiatry at UIC, led the study, published in Depression and Anxiety. The team used fMRI to measure the activity in various regions of the brain, while participants were shown images of violence and were asked not to try to control their reaction or “reappraise” what they saw in a more positive light.

"Reappraisal is something that requires significant mental energy," said Klumpp in a statement. "In people with depression or anxiety, reappraisal can be even more difficult, because these disorders are characterized by chronic negativity or negative rumination, which makes seeing the good in things difficult."

The study featured 78 patients who had been diagnosed with an anxiety disorder, a major depressive disorder or both. They were asked to complete a questionnaire to assess their sleep over the previous month. Participants were also monitored over a six-day period by an actigraph, which measured time awake in bed.

The questionnaire showed  three out of four participants met criteria for significant sleep disturbance, and the actigraph results showed the majority of participants had insomnia. Patients who noted on the questionnaire that they had poor sleep habits were seen to have less brain activity in the DACC during the reappraisal task.

"The questionnaire asks about sleep over the previous month, and answers can be impacted by current mood. Plus, respondents may not be able to accurately remember how they slept a month ago. The actigraph objectively measures current sleep, so the results from both measurements may not match," said Klumpp. "Higher DACC activity in participants with lower levels of sleep efficiency could mean the DACC is working harder to carry out the demanding work of reappraisal."

Klumpp notes that this research indicates that sleep plays a vital role in the ability to regulate negative emotions in patients who suffer from anxiety or depression.