Impaired decision making in opiate addiction correlates with anxiety and self-directedness but not substance use parameters.

BACKGROUND: Despite a large number of empirical reports of impaired decision making in substance use disorders, the underlying factors contributing to such deficits remain to be elucidated. This study examined the potential influences of personality traits, affective symptoms, and pharmacological variables on decision making, as measured by the Iowa Gambling Task (IGT) in a sample of opioid-dependent patients. METHODS: A total of 46 opioid-dependent patients taking part in an opiate maintenance outpatient program and 46 healthy control subjects performed the IGT. Personality traits and affective symptoms were examined by using Zuckerman Sensation-Seeking Scale, the State-Trait Anxiety Inventory and Beck Depression Inventory. In addition, Cloninger Temperament and Character Inventory was administered in the patient group. Information on current and life-time substance use was acquired with a standardized interview. RESULTS: Opioid-dependent patients performed significantly worse on the IGT than controls. This difference disappeared after statistically controlling for trait anxiety, state anxiety, disinhibition, depressive symptoms, and lifetime alcohol consumption. Trait and state anxiety and self-directedness were significantly associated with the IGT final score. Hierarchical regression analyses suggested that self-directedness differentially moderated the relationships between the anxiety variables and IGT performance. CONCLUSIONS: The decision-making impairments observed in opioid-dependent patients are influenced by current levels of anxiety and the personality markers trait anxiety and self-directedness. Differences in decision making between opioid-dependent and healthy individuals may also be due to differences in other personality facets, affective symptoms, and alcohol consumption. Amount of opioid and other substance intake did not show any effects. These results indicate that psychological characteristics may have a higher impact on decision-making performance than drug-induced pharmacological effects.

Decision making of heavy cannabis users on the Iowa Gambling Task: stronger association with THC of hair analysis than with personality traits of the Tridimensional Personality Questionnaire.

BACKGROUND: It is unclear whether impairment in decision making, measured by the Iowa Gambling Task (IGT), in addiction is substance-induced or the consequence of personality structure. METHODS: Analysis of the IGT, the Tridimensional Personality Questionnaire (TPQ) and cannabinoids in hair and urine were performed in 13 cannabis users and matched controls. RESULTS: Hair Delta(9)-tetrahydrocannabinol (THC) correlated negatively with the last subtrial (cards 80-100) of the IGT (R = -0.67). In all participants (n = 26) the TPQ dimension, harm avoidance, correlated negatively with the total IGT score (R = -0.46). The last IGT-subtrial correlated with adventure seeking (R = 0.43), harm avoidance (R = -0.39) and reward dependence (R = -0.44). The last subtrial gives information on whether a participant has learned the IGT strategy. Multiple regression confirmed the impact of THC on the last subtrial, whereas TPQ personality traits did not additionally explain variance. CONCLUSIONS: Former indications of the IGT performance depending on the amount of cannabis consumed were replicated with an objective measurement of chronic cannabis consumption (hair THC). Multiple regression analysis argues for a stronger impact of chronic THC consumption than personality traits, but does not provide a causal relationship. Other factors (e.g. genetic) may also play a role.