Kiril Bozgunov
K. Bozgunov1, E. Psederska1,2, D. Nedelchev1, G. Vasilev1, J. Vassileva3. 1Bulgarian Addictions Institute, Sofia, Bulgaria; 2New Bulgarian University, Bulgaria; 3Virginia Commonwealth University, Richmond VA, United States
Background: Substance dependent individuals (SDIs) are characterized by impaired neurocognitive functioning reflecting deficient decision-making and inhibitory control, and specific vulnerability profiles associated with elevated levels of externalizing (e.g. impulsivity, psychopathy) and internalizing (e.g. depression, anxiety, alexithymia) psychopathology. Research suggests that these impairments are robust and persist even after prolonged abstinence from drug use, increasing the risk of relapse. However, few studies have examined the effect of length of abstinence on neurocognitive and personality functioning in SDIs. The aim of the current study was to investigate differences between SDIs in early abstinence, SDIs in protracted abstinence and a control group of individuals with no history of substance dependence on several neurocognitive, personality and psychiatric measures, commonly used in the addiction literature.
Method: We tested 480 participants (82 SDIs in early abstinence [0-12 months], 190 SDIs in protracted abstinence [>12 months], and 208 control participants) with four decision-making tasks (Cambridge Gambling Task; Iowa Gambling Task; Kirby Delay Discounting Task; Balloon Analogue Risk Task), three response inhibition tasks (Immediate Memory Task; Go/No-Go Task and Stop Signal Task), six measures of externalizing (DSM-IV Antisocial Personality Disorder [ASPD]; Psychopathy Checklist: Screening Version [PCL:SV]; Levenson Self-Report Psychopathy Scale [LSRP]; Sensation Seeking Scale-V [SSS-V]; UPPS Impulsive Behavior Scale [UPPS]; Barratt Impulsiveness Scale-11 [BIS-11]) and four measures of internalizing (State-Trait Anxiety Inventory [STAI]; Anxiety Sensitivity Index [ASI]; Beck Depression Inventory-II [BDI-II]; Toronto Alexithymia Scale-20 [TAS-20]) traits and psychopathology. Structured Clinical Interview for DSM-5 Disorders (SCID) – Clinician Version was used to determine if the individual meets DSM-5 criteria for Substance use disorders and to assess the length of abstinence for participants diagnosed with Substance use disorders. We conducted four multivariate analyses of variance (MANOVAs) examining main effects of length of abstinence on decision-making, response inhibition, externalizing and internalizing psychopathology.
Results: Results reveal that length of abstinence had no significant effect on the composite response inhibition (F (8, 472) = 0.765, p = .726) and decision-making neurocognitive indices (F (8, 420) = 1.467, p = .105). In contrast, length of abstinence had significant main effects on externalizing (F (7, 471) = 22.907, p = .000) and internalizing (F (4, 354) = 2.969, p = .003) psychopathology. Follow-up analyses indicated that individuals in early abstinence were characterized by more symptoms of ASPD, higher levels of psychopathy (both observed on PCL:SV and self-report on LSRP) and trait impulsivity as compared to individuals in protracted abstinence. The control group showed fewer symptoms of conduct disorder and ASPD, lower levels of psychopathy, impulsivity, sensation seeking, and anxiety sensitivity than both substance dependent groups. In addition, control participants had lower levels of depression and alexithymia than individuals in early abstinence.
Conclusions: Our findings reveal that SDIs in short-term abstinence show higher levels of some externalizing (psychopathy, impulsivity) traits than SDIs in long-term abstinence. This suggests that some risk factors associated with higher vulnerability to addiction and risk for relapse may alleviate with abstinence from drug use. However, SDIs in protracted abstinence continue to show higher levels of psychopathy, impulsivity, sensation seeking, and anxiety sensitivity than control individuals, which suggests that these traits could be targeted by personality-based substance abuse interventions. Contrary to expectations, there were no group differences in neurocognitive functioning between short-term and long-term abstinent SDIs; and no group differences between controls and SDIs, regardless of length of abstinence. This suggests that neurocognitive deficits commonly associated with addictive disorders may recover earlier in the course of abstinence. Future studies would benefit from longitudinal designs to evaluate recovery of neurocognitive functioning with abstinence.