Laura Nawijn

Publications (2)6.93 Total impact

• Article: Trait impulsivity predicts escalation of sucrose seeking and hypersensitivity to sucrose-associated stimuli.

  Leontien Diergaarde, Tommy Pattij, Laura Nawijn, Anton N M Schoffelmeer, Taco J De Vries
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  ABSTRACT: Poor impulse control has been associated with compulsive drug seeking and an enhanced risk of relapse, suggesting that impulsivity is causally related to addiction proneness and relapse vulnerability. However, whether this association is specific to drugs of abuse or whether heightened impulsivity relates to a general increase in sensitivity to rewards and reward-associated stimuli is unknown. To address this issue, the authors selected rats on the basis of individual differences in impulsive action in the 5-choice serial reaction time task, after which they were subjected to an operant sucrose self-administration paradigm. High-impulsive rats displayed a progressive increase in responding on the active hole (including responses emitted during the time-out period) in comparison with low-impulsive rats, which reflects escalation of sucrose-seeking behavior. Once sucrose and sucrose-associated stimuli were omitted (extinction training), nose-poke responding ceased rapidly, an effect that was independent of impulsivity level. In contrast, on reintroduction of sucrose-associated stimuli, sucrose seeking was successfully reinstated in high-impulsive but not in low-impulsive rats. Collectively, the results suggest that impaired response inhibition is associated with enhanced responsiveness to reward-associated stimuli. As such, elevated impulsivity might constitute a risk factor for the initiation and maintenance of addictive behaviors.
  Behavioral Neuroscience 09/2009; 123(4):794-803. · 2.62 Impact Factor
• Source

  Available from: psu.edu

  Article: Personality differences in monozygotic twins discordant for cannabis use.

  Jacqueline M Vink, Laura Nawijn, Dorret I Boomsma, Gonneke Willemsen
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  ABSTRACT: To explore the association between cannabis and personality scores when genetic background and shared environment are controlled for. The co-twin control design. This design provides a powerful method for controlling for the effects of potentially confounding familial factors that may act to predispose subjects both to cannabis use and a particular personality profile. 118 monozygotic twin pairs discordant for cannabis use. Data on personality and cannabis use were obtained through a questionnaire survey. The Dutch Sensation Seeking List was used to assess various aspects of sensation seeking. The Amsterdamse Biografische Vragenlijst assessed extraversion, neuroticism, somatic complaints and test attitude. The affected twins scored higher on all scales than their unaffected co-twins, especially on experience seeking (P = 0.004), total sensation seeking score (P = 0.004) and neuroticism (P = 0.039). Differences were also observed when items on drug use were removed from the experience seeking scale (P = 0.037) and total sensation seeking score (P = 0.009) although these differences were no longer significant after Bonferoni correction (P < 0.005). Cannabis use is associated with a higher score on personality scales. This result was obtained in a sample of monozygotic twins discordant for cannabis use. Thus, at least part of the association between cannabis use and experience seeking cannot be attributed to underlying genetic or shared environmental factors that influence both personality and cannabis use and must be explained by unique environmental influences.
  Addiction 12/2007; 102(12):1942-6. · 4.31 Impact Factor