Too little sleep can make everything more difficult. Focusing, coping with everyday stress and completing assignments become immense tasks. Individuals with depression and anxiety often experience sleep issues. However, not much is known with regards to how or if poor sleep is affecting a particular brain area called the dorsal anterior cingulate cortex (DACC), which is involved in the regulation of negative emotional responses.
A study has discovered that this region of the brain might have to work harder in individuals who have poor quality of sleep with anxiety or depression in order to modify their negative emotional responses. Functional MRI was made use of for measuring the activity in various brain areas as the individuals were presented with an emotion regulating task. Disturbing, violent images were shown to them and they were asked to merely look at the images without trying to control their reactions or to “reappraise” what they had seen more positively.
A reappraisal example would be seeing an image of a woman who has a face which is badly bruised and imagining her as an actress in a role with makeup, instead of as a violence survivor. Reappraisal demands a substantial amount of mental energy, and it can be even harder in individuals having anxiety or depression, since both are characterized by chronic negative rumination or negativity, making it difficult to see the positive.
The 78 study participants who were between 18 – 65 years old, and were diagnosed with a major depressive disorder, an anxiety disorder, or both — also filled in a questionnaire for assessing the previous month’s sleep. A motion sensor device known as an actigraph was used to measure their “sleep efficiency,” or the time they were awake in bed, over 6 days. The results of the questionnaire showed that 3 out of 4 individuals met sleep disturbance criteria, and the results from the actigraph indicated most of them had insomnia.
Individuals who noted poorer sleep quality in the questionnaire exhibited less activity in the DACC area of the brain while performing the reappraisal task, and individuals who had reduced sleep efficiency according to the data from the actigraph exhibited higher DACC activity. Because different aspects of sleep experience are measured by the actigraph and the questionnaire, it was no surprise that there was also a difference between these measures in the brain’s activity. Answers to the questionnaire about sleep over the past month can be influenced by current mood. Respondents might also be unable to remember accurately how they slept last month. Current sleep is measured objectively with the actigraph, and the results from both of the measurements might not match. Higher DACC activity in individuals who had lower sleep efficiency levels could mean that the DACC was working harder to accomplish the demanding reappraisal work.
The research indicates that sleep could play an important part in negative emotion regulation ability in individuals suffering from depression or anxiety.