Young women who report having sleeping difficulties “often” in their early 20s have a 4- to 5-times increased risk of depression within 9 years, according to a new study of nearly 10,000 Australian women.
“We also found that young women who reported sleeping difficulties were 12 times more likely to continue to have sleeping problems 9 years later,” Melinda Jackson, PhD, Research Fellow at Victoria University in Melbourne, told ConsultantLive. “This highlights the importance of addressing sleeping issues early on, to prevent future occurrences of sleeping problems and potentially reduce the chance of developing a mental illness.”
Persons with mood disorders, such as depression and anxiety, often have sleep complaints or abnormal sleep patterns, said Dr Jackson. “In fact, sleep problems are found in around 90% of depressed individuals.”
“In an earlier study we found a strong association between difficulty with sleeping and symptoms of depression and anxiety,” she noted. “The link with depressed mood was far stronger than any association between sleep difficulties and a range of behavioral and demographic variables.”
Whether sleep disruptions actually cause subsequent depression is still an unanswered question.
“There is increasing empirical evidence that tackling both depression and sleep issues simultaneously not only improves sleep during depression but also improves the chances of depression remission and decreases the chances of relapse,” said Dr Jackson.
The evidence suggests that behavioral approaches to overcoming sleep difficulties are effective in the short term and more effective than pharmacological approaches in the long term.
In healthy adults, sleep loss can amplify negative emotions (anger, sadness) in response to unpleasant events and lessen positive responses (happiness, joy) to pleasant events.
“Laboratory studies have shown that sleep restriction of 4.5 hours per night for a week can cause people to be more sad, angry, and mentally exhausted. When the participants were allowed to have a normal amount of sleep, their mood improved dramatically,” Dr Jackson said.
“We are still trying to understand exactly how poor sleep affects a person’s mood, but evidence from neuroimaging studies suggests that sleep deprivation may reduce the connectivity between our emotional brain centers (amygdala) and other brain regions (frontal lobes), making people more emotionally reactive and less able to control emotions.”
A number of Internet-based resources are available for clinicians and their patients to help improve sleep. Dr Jackson recommends directing patients to the Sleep Health Foundation Web site for information about what is helpful and unhelpful for sleep problems. The site also has a “Checklist for Health Professionals” with an information sheet on each topic listed.
“Health care professionals can point out the information sheets relevant to the patient, who can then go home and access this information,” said Dr Jackson. Alternatively, individual information sheets (for example, “Ten Tips for a Good Night’s Sleep”) can be downloaded and printed by the health professional and handed to the patient.
Dr Jackson’s colleague Dorothy Bruck, Professor of Psychology at Victoria University, presented the study results recently at the Australian Psychological Society’s Health Psychology Conference.