Scientists from Northwestern University in the United States found that a sleepless night can relieve symptoms of depression for several days. The effect is due to increased dopamine release in certain areas of the brain. The research was published in the journal Neuron.
Doctors have long noticed that acute sleep disorders are associated with changes in mood and behavior. For example, they can trigger mania or sometimes relieve depressive episodes. However, the exact mechanisms that lead to these effects in the brain are not fully understood. To study them, the authors of the new study induced acute sleep loss in a mouse model of depression using a special device that kept them awake.
After a sleepless night, the animals’ behavior changed and became more aggressive, hyperactive and hypersexual compared to the control group that slept as usual. Although most behavioral changes disappeared within a few hours after the acute sleep disturbance, the antidepressant effect persisted for several days.
Biologists examined the areas of the brain responsible for dopamine release: the prefrontal cortex, nucleus accumbens, hypothalamus, and dorsal striatum. They found that in response to a sleepless night, dopamine began to be released more intensely in all regions except the last region. When the scientists blocked dopamine production in the prefrontal cortex, the antidepressant effect disappeared. This means this brain region may be a particularly important target for new antidepressants.
Scientists also found that the release of dopamine after a sleepless night leads to an increase in the plasticity of neurons in the prefrontal cortex, that is, their ability to change in response to stimuli. This is an important reminder of how our daily activities can fundamentally change the brain in just a few hours, the authors noted.
Scientists suggest that brain activation during a sleepless night was necessary for ancient humans to survive, such as when attacked by a predator or other danger. They also did not recommend that people reduce sleep to treat depression, given the short-term effects. The findings are important for choosing the right antidepressant and better understanding how fast-acting antidepressants (such as ketamine) work.
Previous scientists I learnedHe said the pandemic has worsened the mental health of older people.