A new study finds drunk drivers don't just make bad decisions; they may struggle to make any decisions at all.
The findings show people who drove under the influence several times have subtle deficits in their decision making abilities that tend to go undetected though conventional neuropsychological testing.
"Not only was DUI reported to account for nearly 40 percent of fatal motor crashes in North America," which Muzaffer Kasar, resident in psychiatry at the Bakirkoy Research and Training Hospital in Istanbul, Turkey, was quoted as saying. "Thirty-three percent of DUI individuals were recidivists. We wanted to address the underlying neurocognitive mechanisms of recidivism which we assumed might be related to alteration in decision-making cognition."
Researchers evaluated 34 male, second-time DUI offenders, in addition to 31 healthy non-offenders who were matched for age, education and alcohol use. These participants were then given psychiatric assessments, conventional neuropsychology testing, the Iowa Gambling Task (IGT), and lastly the Temperament and Character Inventory (TCI) in order to access personality patterns.
"First, we found that second-time DUI offenders have a poorer performance on the IGT test than their matched counterparts," added Kasar. "The IGT is used in many studies investigating decision-making cognition in problems related to alcohol. Deficits in many neuropsychological testing may not necessarily reflect daily living problems associated with alcohol abuse, as some of the abusers could perform fairly well in conventional neuropsychological testing. That's why problems related to neurocognitive impairments in real-life situations might be better detected by tests such as the IGT which simulate real-life decision-making situations – which our results confirm."
The second finding was a lack of differences between the DUI recidivists and their counterparts using conventional neuropsychological testing and TCI scores. Kasar continues by saying, "These findings suggest that second-time DUI offenders do not suffer from motor impulsiveness, that is, a lack of impulse control in 'here and now' situations. Rather, they suffer from cognitive impulsiveness, which depends on associating negative experiences with possible negative consequences and related to a specific decision-making deficit."
In other words, "there are brain reasons for why people make poor choices regarding DUI," which David J. Nutt, a professor of psychiatry at Imperial College London, was quoted as saying.
"Perhaps our results will increase awareness about brain mechanisms implicated in alcohol-related behavior," said Kasar. "We found a deficit previously shown to be associated with dysfunctioning in particular brain circuits and this may help to change public awareness towards DUI recidivism. Our findings might also influence the framework of psychoeducational programs, and suggest that neurocognitive testing include decision-making tasks such as the IGT as a routine part of the evaluation process."
SOURCE: Alcoholism: Clinical & Experimental Research, December 2010
September 10, 2010
NOTE: This study is being published in the Dec 2010 issue of the journal but was made available online in advance