Responsiveness to Positive Experiences Decreases Vulnerability to Depressive Symptoms of Poor Sleep

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Like good nutrition and physical activities, a healthy quota of sleep is an essential component of good health and overall well-being. In recent times, sleep trouble has escalated in America, with as many as a third of the adult population receiving less than the recommended seven to nine hours of sleep.

The loss, deprivation and disturbance of sleep are not only associated with attention, behavior and learning problems, but also with risks like accidents, injuries, hypertension, obesity, diabetes and depression. The sleepless nights spent in tossing and turning in the bed can spell doom for the people.

While a plethora of factors like electronic media use, caffeine consumption, excess sleeping, etc., may indicate a maladaptive sleep hygiene practice, poor sleep can also be indicative of depression.

Typically, people suffer from sleep disorders due to poor sleep hygiene, which refers to a set of behavioral practices and environmental factors essential for qualitative sleep. In the absence of effective interventions on time, they tend to worsen and could result in mental disorders like depression. As a result, depression has emerged as a prevalent mental disorder that afflicted more than 16.2 million adults in 2016. When the neuroscientists from Duke University tried to understand the link between sleep disorders and depression, they found the following:

  • Not everyone with sleep trouble develops depression.
  • An individual who brain was more attuned to rewards may be at a more advantageous position to stave off the negative mental effects of poor sleep.

Ventral striatum acts as buffer against depressive symptoms

In the study, published in the Journal of Neuroscience, researchers found that college students with poor quality sleep were illegally to develop the symptoms of depression if they exhibited a higher activity in the reward-sensitive part of the brain.

To determine the reasons behind the prevalence of depression in some compared to others, researchers looked closely at the brain region ventral striatum (VS) responsible for regulating motivation and goal directed behavior. They found that the VS assists in reinforcing behaviors that are rewarded and reducing those behaviors that are not rewarded. Prior research has shown that the electrical stimulation of the VS reduces the symptoms of depression in patients, especially those who are resistant to other forms of treatment

To carry out the study, the researchers enrolled 1,129 college students who completed a series of questions, such as the Pittsburgh Sleep Quality Index and the Mood and Anxiety Symptoms Questionnaire, to evaluate sleep quality and depressive symptoms. In addition, they underwent functional magnetic resonance imaging (fMRI) scans while engaging in tasks that activate the VS.

During the above task, the participants were displayed the back of a computer-generated card and instructed to guess whether the value of the card was greater than or less than five. The participants were then given feedback on the accuracy of their guess. However, the entire task was predetermined, with the participants being either right or wrong 80 percent of the time. Upon assessment, researchers found the following results:

  • Individuals who were less susceptible to the effects of poor sleep show significantly higher VS activity in response to positive feedback and reward compared to those who received negative feedback.
  • The high reward-related VS activity may act as a buffer against the depressive symptoms associated with poor sleep.

According to Ahmad Hariri, a professor of psychology and neuroscience at Duke University, "It is almost like this reward system gives you a deficit reserve." He further added, "Poor sleep is not good, but you may have other experiences during your life that are positive. The study findings suggest that the reward-related brain function has the scope to be used as a biomarker for the risk of depression among individuals exposed to negative experiences.

Willingness is key to recovery

A person suffering from depression can not simply "snap out of it." It increases the risk of developing physical illnesses and other chronic diseases. Depression can also lead to suicide, especially when left untreated.