doi: 10.1111/j.1365-2869.2009.00741.x Linking impulsivity to dysfunctional thought control and insomnia: a structural equation model RALPH E. SCHMIDT 1,2 , PHILIPPE GAY 1,2 , PAOLO GHISLETTA 3 and MARTIAL VAN DER LINDEN 1,2 1 Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland, 2 Cognitive Psychopathology and Neuropsychology Unit, Department of Psychology, University of Geneva, Geneva, Switzerland and 3 Methodology and Data Analysis Unit, Department of Psychology, University of Geneva, Geneva, Switzerland Accepted in revised form 6 January 2009; received 8 May 2008 SUMMARY According to cognitive models of insomnia, excessive mental activity at bedtime may be viewed as an important impediment to the process of falling asleep. A further assumption of these models is that Ôcognitive arousalÕ may be perpetuated and exacerbated by counterproductive strategies of thought management. As yet, little is known about factors that may predispose people to rely on these strategies when confronted with thoughts that keep them awake at night. This study examined the relations between impulsivity, use of different thought-control strategies and insomnia severity. A sample of 391 university students completed the UPPS Impulsive Behavior Scale, the Thought Control Questionnaire Insomnia-Revised and the Insomnia Severity Index. Correlation analyses revealed that two facets of impulsivity (urgency and lack of perseverance), two strategies of thought control (aggressive suppression and worry) and insomnia severity were positively associated. Follow-up structural equation modeling analyses showed that the two mentioned thought-control strategies mediated the effects of the two facets of impulsivity on sleep problems. These findings extend existing cognitive accounts of insomnia by suggesting how predisposing and perpetuating factors may be related: specific personality traits may incline individuals to respond with dysfunctional thought-control strategies to unwanted mental activity at night. keywords impulsivity, insomnia, personality, suppression, thought-control strat- egies, worry INTRODUCTION Insomnia figures highly on the list of the most prevalent health complaints. As a recent survey revealed, no fewer than 65% of the adult working population in the USA experience at least one symptom of insomnia a few nights a week or more often, with 44% experiencing at least one symptom every night or almost every night (National Sleep Foundation, 2008). Over the last three decades, behavioral and cognitive approaches have led to significant advances in the etiology (e.g. Harvey et al., 2005) and treatment of this disorder (e.g. Morin et al., 2006). According to these approaches, excessive cognitive activity at bedtime constitutes an important impediment to the process of falling asleep. A central tenet of cognitive accounts of insomnia is that individuals suffering from sleep disturbances tend to adopt counterproductive Ôsafety behaviorsÕ in an attempt to avoid unwanted intrusive thoughts at bedtime (e.g. Espie et al., 2006; Harvey, 2002). In support of this contention, self-report studies have revealed that insomniacs rely on thought-control strategies such as aggressive suppression and worry more often than good sleepers do, and that the use of these techniques predicts poorer sleep (Ellis and Cropley, 2002; Harvey, 2001; Ree et al., 2005; Schmidt et al., 2009). Further evidence for sleep-interfering effects of certain thought-control strategies has come from experimental studies. For instance, thought Correspondence: Ralph E. Schmidt, University of Geneva, Swiss Center for Affective Sciences, Rue des Battoirs 7, CH-1205 Geneva, Switzerland. Tel.: +41-22-379-98-20; fax: +41-22-379-98-44; e-mail: Ralph.Schmidt@unige.ch J. Sleep Res. (2010) 19, 3–11 Insomnia Ó 2009 European Sleep Research Society 3