Role of Personality Traits and impaired Decision-Making and their Relation to Substance Abuse

Substance disorders are the cause of enormous health, social and economical problems today. Psychiatric diseases, personality disorders and cognitive impairment are both risk factors and consequences for substance abuse. Working with these patients put great demands on the clinician’s broad knowledge of co-morbid conditions, diagnostic tools, risk factors and integrated treatment approaches. The psychobiological model by Cloninger represents an attempt to delineate predispositions for developing and maintaining substance abuse. It states that certain configurations of temperament factors (that is: high Novelty Seeking, low Harm Avoidance and low Reward Dependence) predispose the individual for substance disorders. Within a neuropsychological framework, impulsivity is considered a major risk factor for substance disorders. We hypothesize that examinations of decision-making strategies can bridge the concepts of novelty seeking as a temperamental dimension and poor impulse control as a type of executive dysfunction. Several studies using the Iowa Gambling Task, have documented a relationship between deficient decision-making and substance abuse, also indicating that poor decision-making is not a product of substance use; rather, poor decision-making leads to addiction. In the present study, participants with substance abuse will be assessed with both measures of temperament and cognition as well as decision making tests, in order to test the hypothesis that the decision making measures mediate the combined effects of the former two types of measures, on the pattern and prognosis of substance abuse. Key words: personality traits, decision-making task, predictors and substance abuse

Method Applications for approving the project protocol and the letter of informed consent have been send to the Norwegian Social Sciences Services (Norsk Samfunnsvitenskapelig Datatjeneste) and the Regional Committee for Medical Research Ethics and will be discussed at their meeting in October 2008. Clinical sample 90 patients will be recruited from three clinical units. About 50 of these patients will be expected to join the study from a long-term drug abuse treatment centre (Vivestad) mostly for opiate addicted persons. About 40 patients will be recruited from the unit for alcohol/medicament dependency treatment unit and about 10 patients will be recruited from the unit for substitution therapy (LAR). The sex-ratio must be about equal to make analysis of gender effects possible. Demographical data (e.g. education years, having an employment) and current medication will be assessed. Comparison sample A representative Norwegian control sample is available from a project on personality and alcohol use in Norwegian population drawn by Statistics Norway (Statistisk sentralbyrå). Both demographical data, temperament and character data from the TCI and data on alcohol abuse from the AUDIT are available for the study.