Drug addiction endophenotypes: impulsive versus sensation-seeking personality traits.
BACKGROUND
Genetic factors have been implicated in the development of substance abuse disorders, but the role of pre-existing vulnerability in addiction is still poorly understood. Personality traits of impulsivity and sensation-seeking are highly prevalent in chronic drug users and have been linked with an increased risk for substance abuse. However, it has not been clear whether these personality traits are a cause or an effect of stimulant drug dependence.


METHODS
We compared self-reported levels of impulsivity and sensation-seeking between 30 sibling pairs of stimulant-dependent individuals and their biological brothers/sisters who did not have a significant drug-taking history and 30 unrelated, nondrug-taking control volunteers.


RESULTS
Siblings of chronic stimulant users reported significantly higher levels of trait-impulsivity than control volunteers but did not differ from control volunteers with regard to sensation-seeking traits. Stimulant-dependent individuals reported significantly higher levels of impulsivity and sensation-seeking compared with both their siblings and control volunteers.


CONCLUSIONS
These data indicate that impulsivity is a behavioral endophenotype mediating risk for stimulant dependence that may be exacerbated by chronic drug exposure, whereas abnormal sensation-seeking is more likely to be an effect of stimulant drug abuse.
Ersche
Karen D
KD
Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom. ke220@cam.ac.uk
Turton
Abigail J
AJ
Pradhan
Shachi
S
Bullmore
Edward T
ET
Robbins
Trevor W
TW
D000328:Adult; D058068:Endophenotypes; D005260:Female; D006801:Humans; D007175:Impulsive Behavior; D008297:Male; D010555:Personality Inventory; D012309:Risk-Taking; D019966:Substance-Related Disorders / Q000523:psychology*