The causes of insomnia are diverse and span a great many medical conditions, but the underlying brain activity that keeps young and middle-aged adults awake for prolonged periods of time has yet to be determined. The latest issue of the journal Sleep may hold the answer to this dilemma, as scientists discovered that a neurotransmitter, gamma-aminobutyric acid (GABA), is primarily responsible for the chemical imbalance that causes insomnia.
 

"GABA is reduced in the brain of individuals with insomnia, suggesting over-activity is present not only at the level of excessive thoughts and emotions, but can also be detected at the level of the nervous system," said Harvard Medical School affiliate investigator, Dr. John Winkelman of Brigham and Women's Hospital, one of the main authors of the current study.
 

People suffering from sleep disorders complain that their brains remain active even at night, which prevents their thoughts from "settling" down. This state of agitation doesn't allow for sleep. It's like trying to go to bed after an intense event, with the memory of it fresh in your mind. The neural associations that form shortly after the event prevent people from sleeping.
 

The reason for this, the researchers found, is that GABA levels are reduced by as much as 30 percent in people suffering from primary insomnia, which means that their brain activity is no longer inhibited when they are trying to go to sleep. Without this vital transmitter, the state of relaxation that is associated with sleep and rest can no longer set in.
 

"Recognition that insomnia has manifestations in the brain may increase the legitimacy of those who have insomnia and report substantial daytime consequences. Insomnia is not just a phenomenon observed at night, but has daytime consequences for energy, concentration and mood," explained Winkelman, referring to the effects some patients suffering from sleep disorders reported having experienced during the days following sleepless nights.