An advance in understanding drug 'habits' and their treatment

March 26, 2014 by Verity Leatherdale

(Medical Xpress)—Cocaine promotes habitual behaviours and these can potentially be reversed with the use of an antioxidant, research at the University of Sydney has shown.

The findings have just been published in Neuropsychopharmacology.

For many people the term 'habit' has a negative connotation and uncontrolled use is the quintessential 'bad habit'.

"But in fact the assumption that drug use is habit-forming and, if so, why, has rarely been scientifically tested," said Dr Laura Corbit, from the University's School of Psychology and lead author on the paper with Professor Bernard Balleine from the Brain and Mind Research Institute at the University.

"There are two possible scenarios for compulsive drug use. One is that the drug is highly valued by the user and this drives active, deliberate pursuit of the drug. The second is that when a user finds themselves in a situation where they've used drugs before, they do so again regardless of the desire to use or abstain - their behaviour has become habitual," Dr Corbit said.

"We show that exposure to cocaine speeds up habit learning and, importantly, this effect is not limited to drug use. We also discovered that these drug-induced habits can be prevented by taking an antioxidant, N-acetylcysteine (NAC)," Dr Corbit said.

This tendency for drug-related and other behaviours to become habitual may present a significant challenge for drug-users as they are essentially having to change behaviour overall, not just their drug-taking.

The researchers modelled the effects of long-term cocaine exposure in rats and tested their reward-seeking behaviour using food.

"In cocaine-treated rats their behaviour rapidly became habitual but in the control animals, not receiving the cocaine, it remained flexible," Dr Corbit said.

"Strikingly we saw that, in the rats' brains, there were changes in regions needed to make flexible decisions rather than in the habit-forming part of the brain. So impaired decision making may allow for earlier control by habits."

Rats given NAC at the same time as the cocaine were indistinguishable from controls - rats that were not receiving either drug. The effects of cocaine were prevented, with goal-directed, as distinct from habitual, behaviour observed in the NAC-treated .

"The effects of cocaine are not limited just to behaviours related to taking the drug. Our findings suggests that what lies at the heart of addiction is not only decisions about drug seeking but a more general cognitive rigidity - or inability to control our behaviour," Dr Corbit said.

"That is why these preliminary findings with NAC are encouraging. Its ability to reduce craving and relapse risk are established. Future research will confirm its potential to improve goal-directed decision-making which promises better treatment outcomes for interventions such as ," Dr Corbit said.

Explore further: Sons of cocaine-using fathers may resist addiction to drug, study suggests

More information: "Effects of Repeated Cocaine Exposure on Habit Learning and Reversal by N-Acetylcysteine." Corbit LH, Chieng BC, Balleine BW. Neuropsychopharmacology. 2014 Feb 17. DOI: 10.1038/npp.2014.37. [Epub ahead of print]

Related Stories

Sons of cocaine-using fathers may resist addiction to drug, study suggests

November 11, 2013
A father's cocaine use may make his sons less sensitive to the drug and thereby more likely to resist addictive behaviors, suggests new findings from an animal study presented by Penn Medicine researchers at Neuroscience ...

Structural and functional changes that cocaine cause in the brain favour addiction

March 5, 2014
Cocaine use produces structural changes in the brain reducing the volume of certain regions, and also functional changes affecting motivational and cognitive processes. These changes favour addiction. The objective of a project ...

Abnormal brain structure linked to chronic cocaine abuse

June 21, 2011
Researchers at the University of Cambridge have identified abnormal brain structures in the frontal lobe of cocaine users' brains which are linked to their compulsive cocaine-using behaviour. Their findings were published ...

Animal models demonstrate that the net result of cocaine use is a balance of both positive and negative effects

March 5, 2014
On the other side of the cocaine high is the cocaine crash, and understanding how one follows the other can provide insight into the physiological effects of drug abuse. For decades, brain research has focused on the pleasurable ...

Scientists focus on brain protein and antibiotic to block cocaine craving

June 3, 2013
A new study conducted by a team of Indiana University neuroscientists demonstrates that GLT1, a protein that clears glutamate from the brain, plays a critical role in the craving for cocaine that develops after only several ...

Researchers find glutamate receptor helps suppress cue induced cocaine craving

November 25, 2013
(Medical Xpress)—A team of researchers with members from several universities in the U.S. has found that a glutamate receptor given to test rats addicted to cocaine caused a reduction in cue induced cravings for the drug. ...

Recommended for you

Concern with potential rise in super-potent cannabis concentrates

July 21, 2017
University of Queensland researchers are concerned the recent legalisation of medicinal cannabis in Australia may give rise to super-potent cannabis concentrates with associated harmful effects.

Findings link aldosterone with alcohol use disorder

July 18, 2017
A new study led by scientists at the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health, demonstrates that aldosterone, a hormone produced in the adrenal glands, may contribute ...

Depression among young teens linked to cannabis use at 18

July 17, 2017
A study looking at the cumulative effects of depression in youth, found that young people with chronic or severe forms of depression were at elevated risk for developing a problem with cannabis in later adolescence.

Why does prenatal alcohol exposure increase the likelihood of addiction?

July 7, 2017
One of the many negative consequences when fetuses are exposed to alcohol in the womb is an increased risk for drug addiction later in life. Neuroscientists in the University at Buffalo Research Institute on Addictions are ...

Researchers say U.S. policies on drugs and addiction could use a dose of neuroscience

June 23, 2017
Tens of thousands of Americans die from drug overdoses every year – around 50,000 in 2015 – and the number has been steadily climbing for at least the last decade and a half, according to the National Institute on Drug ...

Study provides further support for genetic factors underlying addictions

June 13, 2017
Impairment of a particular gene raises increases susceptibility to opioid addiction liability as well as vulnerability to binge eating according to a new study.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.