Effects of length of abstinence on decision-making and craving in methamphetamine abusers

Abstract

Rationale: The majority of drug abusers are incapable of sustaining abstinence over any length of time. Accumulating evidence has linked intense and involuntary craving, Impulsive decision-making and mood disturbances to risk for relapse. However, little is known about temporal changes of these neuropsychological functions in methamphetamine (METH)-dependent individuals.

Objectives: To investigate the effect of length of abstinence on decision-making, craving (baseline and cue-induced), and emotional state in METH-addicted individuals.

Methods: In this cross-sectional study, 183 adult METH-dependent patients at an addiction rehabilitation center who were abstinent for 6 days (n = 37), 14 days (n = 33), 1 month (n = 31), 3 months (n = 30), 6 months (n = 26), or 1 year (n = 30) and 39 healthy subjects were administered the Iowa Gambling Task (IGT) to assess decision-making performance. Depression, anxiety, and impulsivity were also examined. One hundred thirty-nine METH abusers who were abstinent for the aforementioned times then underwent a cue session, and subjective and physiological measures were assessed.

Results: METH dependent individuals who were abstinent for longer periods of time exhibited better decision-making than those who were abstinent for shorter periods of time. And self-reported emotional symptoms improved with abstinence. METH abusers' ratings of craving decreased with the duration of abstinence, while cue-induced craving increased until 3 months of abstinence and decreased at 6 months and 1 year of abstinence.

Conclusions: We present time-dependent alterations in decision-making, emotional state, and the incubation of cue-induced craving in METH-dependent individuals, which might have significant clinical implications for the prevention of relapse.

Figure 1. Decision-making ability on the Iowa Gambling Task (IGT) in METH abusers at different abstinence times and healthy controls over 100 card choices.

Differences between advantageous and disadvantageous choices ([C+D] - [A+B]) are expressed as mean ± SEM. *p<0.05, differences between METH abusers groups and normal controls (post hoc t-test). ^# p<0.05, differences between 6 d and 12 m abstinence group.

Figure 2. Anxiety, depression, and attention in the subjects.

*p<0.05, significant difference between METH abusers and healthy controls.

Figure 3. Self-reported impulsivity on the BIS-11 in the subjects.

*p<0.05, significant difference between METH abusers and healthy controls.

Figure 4. Effects of length of abstinence on baseline (nonprovoked) METH craving.

*p<0.05, **p<0.01, compared with 6 d group; ^# p<0.05, ^## p<0.01, compared with 14 d group. The data are expressed as group means (± SEM).

Figure 5. Effects of exposure to METH and neutral cues on self-reported craving as a function of length of abstinence.

*p<0.05, compared with 3 m group. The data are expressed as group means (± SEM).