Insomnia Linked to GABA Deficiency

Researchers found gamma-aminobutyric acid (GABA), the most common inhibitory transmitter in the brain, is reduced by nearly 30 percent in individuals who have been suffering from primary insomnia for more than six months.

“GABA is reduced in the brain of individuals with insomnia, suggesting overactivity 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 principal investigator Dr. John Winkelman of Brigham and Women’s Hospital, a teaching affiliate of Harvard Medical School.

GABA decreases overall activity in many brain areas, helping the brain to “shut down.” Having a “racing mind” and an inability to shut down at night is a common complaint of people with primary insomnia.

According to Winkelman, the recognition that primary insomnia is associated with a specific neurochemical deficiency helps validate the often misunderstood complaint of insomnia.

“Recognition that insomnia has manifestations in the brain may increase the legitimacy of those who have insomnia and report substantial daytime consequences,” he said.

“Insomnia is not just a phenomenon observed at night, but has daytime consequences for energy, concentration and mood.”

According to the study, reductions in brain GABA levels also have been observed with 1H-MRS in major depressive disorder (MDD) and anxiety disorders. Primary insomnia shares many features with anxiety and depressive disorders, including sleep disturbance, elevation in anxiety, and impairments in concentration and energy.

In addition, primary insomnia is an important risk factor for incident mood and anxiety disorders. The study raises the possibility that GABA deficiencies seen in people with mood and anxiety disorders may be based on disturbances in sleep.

link: Insomnia Linked to Neurochemical Imbalance