Negative emotionality 'may make some people prone to substance use'
A high level of negative emotionality may lead to problem drinking when it occurs together with sensitivity to a drug-based reward, a new study has suggested.
Prior research has shown that sensitivity to the stimulating effects of alcohol and other drugs is a risk marker for heavy or problematic use of those substances. Prior research has also shown that the personality trait of negative emotionality can have an effect on substance use.
A new study examining how the response to an amphetamine interacts with negative emotionality to influence alcohol and drug use has found that a high level of negative emotionality may lead to problem drinking when it occurs together with sensitivity to a drug-based reward.
"Alcohol is commonly thought of as a sedative; in sufficient amounts, it slows people's mental and physical reactions," Frances H. Gabbay, corresponding author of the study from the Uniformed Services University of the Health Sciences, said.
"However, alcohol also has positive, stimulating effects that are particularly noticeable a short time after someone starts drinking. People differ in their sensitivity to these effects.
"Some may find that drinking alcohol makes them feel excited, energetic, and talkative while others may feel down, sluggish, and sedated. Heavy drinkers and those with a family history of alcoholism tend to report greater stimulant effects compared to light drinkers and those with no such family history," he said.
For the study, researchers recruited 192 participants (99 women, 93 men), 18 to 25 years old, who completed the Multidimensional Personality Questionnaire (MPQ) to assess negative emotionality, and answered questions pertaining to alcohol and other drug use.
The participants then received 10 mg d-amphetamine, and their self-reported drug effects were assessed. The researchers then evaluated the relationship between the subjective response to amphetamine and MPQ negative emotionality on the measures of substance use.
"This work supports the idea that the amount of alcohol people drink is at least partly determined by differences in personality and responsiveness to drugs," Gabbay said.
"Specifically, our study suggests that people who are sensitive to the stimulating effects of a low dose of amphetamine and who also experience powerful negative moods may be prone to drink excessively.
"Negative emotions may motivate a desire for immediate reward, which we believe encourages heavy drinking among people who are sensitive to the rewarding effects of drugs. Individuals who find drugs less rewarding may not be tempted to drink when they experience negative emotions.
"We also found an association between the reaction to amphetamine and the use of illicit substances, which suggests that people who are sensitive to the rewarding effects of one type of drug may be more likely to use other drugs," he added.
Gabby also noted that prior research has shown that most drugs increase midbrain dopamine, and that this increase is related to their stimulating effects.
The study will be published in Alcoholism: Clinical and Experimental Research.