We aimed to compare adult patients with attention deficit hyperactivity disorder (ADHD) and matched controls on four dimensions of impulsivity (urgency, lack of premeditation, lack of perseverance, and sensation seeking) and to examine the association between impulsivity and ADHD symptoms. The study was conducted on 219 participants: 72 adult ADHD patients and 147 aged and gender matched controls. All participants completed questionnaires measuring the various facets of impulsivity (UPPS Impulsive Behavior Scale), ADHD and depressive symptoms severity. Patients were also assessed for ADHD subtypes, mood disorders, and addictive behaviors. ADHD patients exhibited higher urgency, lower premeditation and lower perseverance in comparison to controls. Lack of perseverance showed the strongest association with ADHD (area under curve=0.95). Patients with combined inattentive and hyperactive/impulsive subtypes reported more frequently substance abuse problems and had higher scores on urgency and sensation seeking dimensions of impulsivity than those with predominantly inattentive subtype. We report for the first time a multidimensional evaluation of impulsivity in adult ADHD patients. The UPPS Impulsive Behavior Scale may constitute a useful screening tool for ADHD in adults and may help to further understanding the psychological mechanisms underlying the differences between the ADHD subgroups.
Attention deficit hyperactivity disorder (ADHD) is one of the most prevalent psychiatric disorders with estimated prevalence ranging from 3% to 5% in adults (Faraone and Biederman, 2005 and Fayyad et al., 2007), with a 2.99% prevalence in France (Caci et al., 2014). Depending on the number of inattention, hyperactivity or impulsivity symptoms, the diagnostic formulation, as specified by the Diagnostic and Statistical Manual of Mental Disorders 4th edition, text revision (DSM-IV-TR) (American Psychiatric Association, 2000), includes three distinct subtypes: (1) ADHD Predominantly Inattentive (ADHD-PI), (2) ADHD Predominantly Hyperactive/Impulsive,(ADHD-HI) and (3) ADHD Combined (ADHD-C) subtypes. Impulsivity is a core symptom of ADHD. In fact, the DSM-IV-TR proposes three criteria to clinically assess impulsivity in ADHD (i.e., blurts out answers before questions have been completed; fails to await turns in games or group situations; interrupts or intrudes on others). These criteria that mainly concern the behavioral aspect of impulsivity observed in ADHD children do not cover some specific impulsive symptoms frequently recorded in adults.
Various researchers have attempted to measure impulsivity with self-reported measures. Buss and Plomin (1975) proposed the Emotionality, Activity, Sociability, and Impulsivity Temperament Survey, with subscale such as inhibitory control, sensation seeking. Zuckerman et al. (1964) used two subscales to assess impulsivity (sensation seeking and boredom susceptibility). Patton et al. (1995) measured impulsivity with the Barrat Impulsive Scale including different factors (attentional impulsivity, motor impulsivity, and non-planning impulsivity). The Eysenck impulsivity questionnaire (Eysenck et al., 1985) was designed to assess dysfunctional aspect of impulsivity. Finally, several subscales of the NEO Personality Inventory (Costa et al., 1985) (e.g. impulsiveness, deliberation, and self-discipline) are also dedicated to measure impulsivity as well as the impulsivity scales of Cloninger׳s Temperament and Character Inventory (Cloninger, 1987).
In the present study, we capitalized on the multi-factorial construct of impulsivity proposed by Whiteside and Lynman in the early 2000s (Whiteside and Lynam, 2001). These authors proposed a model for understanding the personality pathways to impulsive behaviors. They identified four distinct traits associated with impulsive-like behaviors (i.e., urgency, lack of premeditation, lack of perseverance, and sensation seeking) and proposed the UPPS Impulsive Behavior Scale (Whiteside et al., 2005). The early measures of impulsivity reviewed above can be aligned along one of these four dimensions, therefore providing an organized structure of the multi-faceted construct of impulsivity. The first dimension of the UPPS scale, urgency, refers to the tendency to act rashly when faced to intense negative emotions. The second, (lack of) premeditation, is characterized by an inability to consider the potential consequences of one׳s behavior. The third, (lack of) perseverance, refers to the lack of ability to stay on task while experiencing boredom and/or difficulty in realizing the task. Finally, sensation seeking refers to an individual׳s need for excitement and stimulation, as well as openness to new experiences.
These four dimensions correlated with and differently predict risky behaviors and clinical symptoms that may be associated with ADHD. Hence urgency may relate to both mood disorders, substance dependence and craving (Billieux et al., 2007 and Verdejo-García et al., 2007), pathological gambling (Billieux et al., 2012), cyber addictions (Billieux et al., 2010), or eating disorders (Mobbs et al., 2010); lack of perseverance to procrastination-related behaviors (Dewitte and Schouwenburg, 2002) and risky sexual conducts (Miller and Lynam, 2003); lack of premeditation to antisocial personality, and substance abuse (Miller et al., 2003); and sensation seeking to drug and alcohol use as well as with gambling and delinquent acts (Miller et al., 2003 and Smith et al., 2007).
The presence of impulsivity based on the UPPS model was assessed in an isolated children ADHD study showing elevated levels of urgency, lack of perseverance, and lack of premeditation in patients compared to controls, with a large level of urgency found in children with ADHD comorbid with behavioral problems (Miller et al., 2010).
To the best of our knowledge, no similar multidimensional approach of impulsivity was performed in adult ADHD patients. The aims of the present study are: (1) to compare the four dimensions of impulsivity (urgency, lack of premeditation, lack of perseverance, and sensation seeking) in adult ADHD patients in comparison with sex- and age-matched normal controls; (2) to determine the optimally efficient UPPS cut-point to discriminate patients from controls, and (3) to precise the association between UPPS impulsivity facets and ADHD subtypes. Finally, we investigated the relationship between substance abuse and mood disturbances, and ADHD subtypes.
