Abstract: Background: Greater temporal discounting has been
associated with a range of problematic impulsive behaviors
including substance abuse, obesity, and pathological
gambling. It is not known whether greater temporal
discounting precedes or is an effect of these behaviors.
Here we examine temporal discounting and cannabis use in
a large longitudinal sample of adolescents collected by the
IMAGEN consortium (http://www.imagen-europe.com).
Methods: Individual temporal discounting rates measured by
Kirby’s Monetary Choice Questionnaire and lifetime use of
cannabis estimated by the European School Survey on
Alcohol and Other Drugs (ESPAD) was assessed at three
time points: 14, 16, and 18 years old. Complete data at each
timepoint was available in 1120 adolescents. The bidirectional
relationships between these two variables across time were
examined using an autoregressive cross-lagged model
Results: The overall model fit was good (λ250.16, df52,
p50.9; RMSEA 5 0.001; CFI 5 1.0). There were three main
findings: i) stability paths for temporal discounting and
cannabis use were significant across time, ii) temporal
discounting and cannabis use were significantly correlated at
each time point, and iii) temporal discounting significantly
predicted future cannabis use but cannabis use did not predict
future rates of temporal discounting.
Conclusions: The results are consistent with the notion that
impulsivity is a cause rather than an effect of cannabis use.
Early interventions which lower temporal discounting in
impulsive adolescents may be an effective investment
against future problematic drug use.