Trouble Sleeping? Primary Insomnia Better Understood

Nov. 05, 2008 — A specific neurochemical imbalance found in adults with primary insomnia makes it more difficult for their brains to settle down for sleep, a new study says.

Many adults suffering from insomnia complain of a 'racing mind' and an inability to shut down at night. Researchers now suggest this experience is not just "in your head", but a result of a decrease in the neurochemical gamma-aminobutyric acid (GABA).

Insomnia Linked to GABA Deficiency
According to a medical journal Sleep, people with primary insomnia for more than six months have 30 percent less GABA, a chemical that slows overall activity in many brain areas.

"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," principal investigator John Winkelman, MD, PhD of Brigham and Women's Hospital in Boston, says.

In many cases, secondary insomnia - the most common type - occurs in conjunction with another illness or disorder, either physical or mental, or as a side effect of certain medications or substances. However, primary insomnia occurs without a coexisting condition, persists for one month or longer, and effects approximately a quarter of the adult population.

Greater Insights Into Insomnia
The finding suggests that primary insomnia is a manifestation of hyperarousal, a neurobiological state, that Dr. Winkelman says helps validate an 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 says. "Insomnia is not just a phenomenon observed at night, but has daytime consequences for energy, concentration and mood."

Possible Correlation to Other Disorders
Lower brain GABA levels also have been found in people with major depressive disorder (MDD) and anxiety disorders. It is also noted that primary insomnia shares many features with these conditions and is a critical risk factor. As a result, the study raises the possibility that GABA deficiencies seen in people with mood and anxiety disorders may be tied to sleep disturbances.

The study further states that many of the hypnotic medications most effective in treating insomnia are benzodiazepine receptor antagonists (BzRAs), which increase activity at the GABA neurons. GABA is considered to be one of the factors that help promote sleep and is also involved in cognitive, memory and psychomotor functions.

Treatment for Primary Insomnia
Standard treatment options for insomnia generally include lifestyle changes, cognitive-behavioral therapy, and sleep medicines, or hypnotic medications.

According to a new clinical guideline published by the American Academy of Sleep Medicine in the Journal of Clinical Sleep Medicine, hypnotic treatment should be supplemented with behavioral and cognitive therapies whenever possible in the evaluation and management of chronic insomnia in adults.

Always consult your physician for more information.