Pubdate: Sun, 28 Jun 2015
Source: Aspen Times, The  (CO)
Author: Jill Beathard


Illness and changes that occur in the brain all can be factors in why 
some people get addicted to drugs and alcohol, a top national 
researcher said in an Aspen Institute Spotlight Health seminar Saturday.

There is a common belief that people become addicted to something 
because they enjoy the feeling they get from it, but the biological 
process of losing control over one's behavior is more complex than 
that, said Dr. Nora D. Volkow, the director of the National Institute 
on Drug Abuse, in a session titled "oeThe Biology of Addiction - Why 
Do We Get Hooked?"

Rewards motivate humans to take certain actions, which is a crucial 
aspect of our biology because it includes behaviors such as eating 
and sex, Volkow said. But early in her research on addiction, Volkow 
questioned why someone would become so addicted to a pleasurable 
experience that they would lose their control over the behavior and 
choose it despite "catastrophic consequences."

Abusing drugs creates a pleasurable feeling by increasing levels of 
the neurotransmitter dopamine in the reward centers of the brain. 
Studying cocaine abuse by using methylphenidate, a safer drug that 
has similar effects when injected, Volkow found that the brains of 
addicts had less than half the pleasurable response to the drug that 
non-addicts did.

Volkow followed that by monitoring the reactions of a control group 
and addicts to images of people using drugs and paraphernalia. 
Addicts would get a craving when they saw the images, causing the 
dopamine levels in their brain to rise, but then if they consumed, 
the pleasurable response did not occur.

"They're not more sensitive to the rewarding effect but conditioned 
to it,"  Volkow said.

Research also has shown that receptors to dopamine are fewer in the 
brains of addicts. Activity in the frontal cortex, which helps with 
decision making and self-control, is compromised as well. Those 
phenomena can occur due to pre-existing conditions such as genetics 
and mental illness, but they also can occur as a result of changes in 
the brain due to substance abuse or a combination of factors.

"No one chooses to be an addict,"  Volkow said. "Their brains have 
been rewired in such a way to lead to an automatic response when they 
are in an environment (where the substance is available)."

Volkow believes treatment for addiction should take a multi-pronged 
approach of helping patients enhance their self-control, disrupt 
positive memories of past pleasurable experiences with substances and 
find other motivators that create positive reinforcement.

"Addiction can be prevented or treated, but we're not doing either 
one,"  Volkow said, although later she said that she should have 
added "sufficiently,"  as the country has made great strides in 
combating tobacco addiction and some of the negative consequences of 
alcohol abuse, such as accidents and drinking among teens.
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