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Wake Forest University Baptist Medical Center Press Release, October
27, 2004
New Finding about Alcohol and Sleep
WINSTON-SALEM, N.C. – New research about how alcohol affects sleep
could lead to medications to address a common reason some alcoholics
go back to drinking – disturbed sleep when they try to stop. The work
was reported today by researchers from Wake Forest University Baptist
Medical Center at the annual meeting of the Society for Neuroscience
in San Diego.
“There is a strong relationship between alcohol and sleep,” said
Dwayne Godwin, Ph.D., senior researcher. “Many people have sleep problems
when they stop drinking. If we could stabilize sleep, or take it back
to a normal rhythm, it would address one of the reasons that alcoholics
go back to drinking.”
Godwin and colleagues studied the relationship between sleep and
alcohol in monkeys. They found that in animals that chronically drank
alcohol, the brain attempts to increase a particular protein associated
with brain waves that are important to normal sleep. The finding suggests
that new medications to target the protein might improve sleep in
chronic alcohol users.
“If we can find a way to solve the problem of sleep disturbance,
it could possibly affect the outcome of addiction treatment,” said
Godwin.
Previous research in animals and humans has shown that alcohol initially
acts as a sedative in casual drinkers, making it easier to sleep.
But in the second half of the night, sleep is often disrupted. In
chronic alcohol users, the brain develops a tolerance to the sedative
effects of alcohol and there is an increase in light sleep and a decrease
in restorative sleep. This may prompt alcohol users to increase their
consumption to try to improve sleep. One study revealed that 44 percent
to 60 percent of alcohol patients used alcohol to help them sleep.
Godwin said the brain adapts to long-term alcohol use and doesn’t
immediately return to normal when alcohol use is stopped. It may take
months for the brain to revert to normal sleep patterns, or it may
never return to a truly normal state. In the meantime, sleep problems
can get worse. Insomnia has been shown to occur in 36 percent to 72
percent of alcoholic patients during both active drinking and withdrawal.
“There is a significant relationship between alcoholics returning
to consumption because of this sleep issue,” said Godwin, an associate
professor of neurobiology and anatomy. “One reason they may go back
to drinking may be an attempt to make their sleep feel more normal
or satisfying.”
Previous research has shown that alcohol affects spindle waves,
which are brain rhythms associated with normal sleep. The primary
generators of spindle waves are proteins called calcium channels that
are involved with cell communication. These channels may also help
to set the phase of sleep.
Chronic alcohol consumption has been shown to disturb the function
of calcium channels in the thalamus, a brain region involved in sleep.
In the current study, Godwin and colleagues found that animals that
self-administered alcohol had a fourfold increase in one of the genes
that express the calcium channels, compared to animals that didn’t
consume alcohol.
“The alcohol suppresses the calcium channels, so the cells in the
thalamus may compensate by making more copies of the gene,” said Godwin.
“However, this overproduction of the gene did not lead to an increase
in functional calcium channels and the cells still had disturbances
in the channels, so the animals as a group tended to have disrupted
sleep.”
Godwin and colleagues plan to continue the work to learn how alcohol
disrupts the protein. Does it reduce the number of calcium channels?
Or does it cause the channels to malfunction? Knowing more about how
the channels respond to alcohol could lead to drugs that could target
the calcium channels and address sleep problems associated with alcohol.
Related: Sleep problems in early childhood and early
onset of alcohol and other drug use in adolescence.
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