Two-month stability of hyperbolic discount rates for delayed monetary gains in abstinent inpatient alcoholics.
OBJECTIVE
Alcohol dependence has been associated with disrupted neuroendocrine systems, impulsivity in intertemporal choice (delay discounting). However, little is known regarding stability of discount rates in alcoholics. This study examined both differential stability (stability of individual differences) and absolute stability (stability of group mean) of hyperbolic discount rates for monetary gains in severe alcoholic inpatients (diagnosed with DSM-IV) over a 2-month period during abstinence.


METHODS
We estimated male alcoholics' discount rates for delayed monetary rewards on the basis of their pattern of choices between smaller immediate rewards (1,100-8,000 yen) and larger, delayed rewards (2,500-8,500 yen; at delays from 1 week to 6 months), two times at 2-month time-interval during hospitalized alcohol withdrawal.


RESULTS
It was observed that the alcoholics' mean hyperbolic discount rates for gains had both differential and absolute stability over 2 months, although a slight non-significant decrease in the group mean of the discount rates was observed.


CONCLUSIONS
The results indicate that abstinent alcoholic's discount rates are stable over a relatively long-term period. The usefulness of assessing discount rates of addicts in psychoneuroendocrinology and neuroeconomics of addiction is discussed.
Takahashi
Taiki
T
Department of Cognitive and Behavioral Science, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan. taiki@ecs.c.u-tokyo.ac.jp
Furukawa
Aizo
A
Miyakawa
Tomohiro
T
Maesato
Hitoshi
H
Higuchi
Susumu
S
D000437:Alcoholism / Q000517:prevention & control* / Q000523:psychology*; D002755:Choice Behavior / Q000502:physiology*; D006801:Humans; D007175:Impulsive Behavior / Q000209:etiology; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D012201:Reward; D013997:Time Factors