Browsing by Author "Milich, Richard"

Now showing 1 - 8 of 8
  • Thumbnail Image
    Item
    Does Response Variability Predict Distractibility among Adults with Attention-Deficit/Hyperactivity Disorder?
    (American Psychological Association, 2011) Adams, Zachary W.; Roberts, Walter M.; Milich, Richard; Fillmore, Mark T.; Psychiatry, School of Medicine
    Increased intra-individual variability in response time (RTSD) has been observed reliably in ADHD and is often used as a measure of inattention. RTSD is assumed to reflect attentional lapses and distractibility, though evidence for the validity of this connection is lacking. We assessed whether RTSD is an indicator of inattention by comparing RTSD on the stop-signal task (SST) to performance on the Delayed Oculomotor Response (DOR) Task, a measure of distractibility. Participants included 30 adults with ADHD and 28 controls. Participants completed the SST and the DOR task, which measured subjects’ ability to maintain attention and avoid distraction by inhibiting reflexive saccades toward distractors. On the SST, the ADHD group was slower to inhibit than controls, indicating poorer inhibitory control in ADHD. The ADHD group also displayed slower RTs, greater RTSD, and more omission errors. On the DOR task, the ADHD group displayed more premature saccades (i.e., greater distractibility) than controls. Greater variability in RT was associated with increased distraction on the DOR task but only in ADHD participants. Results suggest that RTSD is linked to distractibility among adults with ADHD and support the use of RTSD as a valid measure of inattention in ADHD.
  • Thumbnail Image
    Item
    Drinking Motives as Mediators of the Impulsivity-Substance Use Relation: Pathways for Negative Urgency, Lack of Premeditation, and Sensation Seeking
    (Elsevier, 2012) Adams, Zachary W.; Kaiser, Alison J.; Lynam, Donald R.; Charnigo, Richard J.; Milich, Richard; Psychiatry, School of Medicine
    Trait impulsivity is a reliable, robust predictor of risky, problematic alcohol use. Mounting evidence supports a multidimensional model of impulsivity, whereby several distinct traits serve as personality pathways to rash action. Different impulsivity-related traits may predispose individuals to drink for different reasons (e.g., to enhance pleasure, to cope with distress) and these different motives may, in turn, influence drinking behavior. Previous findings support such a mediational model for two well-studied traits: sensation seeking and lack of premeditation. This study addresses other impulsivity-related traits, including negative urgency. College students (N = 432) completed questionnaires assessing personality, drinking motives, and multiple indicators of problematic drinking. Negative urgency, sensation seeking, and lack of premeditation were all significantly related to problematic drinking. When drinking motives were included in the model, direct effects for sensation seeking and lack of premeditation remained significant, and indirect effects of sensation seeking and lack of premeditation on problematic drinking were observed through enhancement motives. A distinct pathway was observed for negative urgency. Negative urgency bore a significant total effect on problematic drinking through both coping and enhancement motives. This study highlights unique motivational pathways through which different impulsive traits may operate, suggesting that interventions aimed at preventing or reducing problematic drinking should be tailored to individuals' personalities. For instance, individuals high in negative urgency may benefit from learning healthier strategies for coping with distress.
  • Thumbnail Image
    Item
    Identifying the facets of impulsivity that explain the relation between ADHD symptoms and substance use in a nonclinical sample
    (Elsevier, 2014) Roberts, Walter; Peters, Jessica R.; Adams, Zachary W.; Lynam, Donald R.; Milich, Richard; Psychiatry, School of Medicine
    Adults with attention-deficit/hyperactivity disorder (ADHD) are at higher risk to use substances than their nonclinical peers. Increased levels of impulsivity are generally thought to contribute to their increased levels of risk. Impulsivity is a multifaceted construct, however, and little research to date has attempted to identify which facets of impulsivity contribute to the increased rates of substance abuse among individuals with ADHD. The current study examined the relation among ADHD symptom clusters (i.e., hyperactivity/impulsivity and inattention), substance use rates (i.e., alcohol use, nicotine use, and marijuana use), and personality processes associated with impulsive behavior in a group of young adults. Participants were 361 undergraduate students. Both symptom clusters were positively associated with rates of substance use. Specifically, hyperactive/impulsive symptoms were associated with alcohol and nicotine use, and inattentive symptoms were associated with alcohol use. Several pathways from hyperactive/impulsive symptoms to alcohol, nicotine, and marijuana use via specific facets of impulsivity were identified. These findings have implications for understanding the relation between ADHD symptoms and substance use, as well as clinical implications for preventing and treating substance use problems in individuals with symptoms of ADHD.
  • Thumbnail Image
    Item
    Inhibitory Functioning across ADHD Subtypes: Recent Findings, Clinical Implications and Future Directions
    (Wiley, 2008) Adams, Zachary W.; Derefinko, Karen J.; Milich, Richard; Fillmore, Mark T.; Psychiatry, School of Medicine
    Although growing consensus supports the role of deficient behavioral inhibition as a central feature of the combined subtype of ADHD (ADHD/C; Barkley, 2007; Nigg, 2001), little research has focused on how this finding generalizes to the primarily inattentive subtype (ADHD/I). This question holds particular relevance in light of recent work suggesting that ADHD/I might be better characterized as a disorder separate from ADHD/C (Diamond, 2005; Milich et al., 2001). The current paper describes major findings in the area of inhibitory performance in ADHD and highlights recent research suggesting important areas of divergence between the subtypes. In particular, preliminary findings point to potential differences between the subtypes with respect to how children process important contextual information from the environment, such as preparatory cues that precede responses and rewarding or punishing feedback following behavior. These suggestive findings are discussed in the context of treatment implications, which could involve differential intervention approaches for each subtype targeted to the specific deficit profiles that characterize each group of children. Future research avenues aimed toward building a sound theoretical model of ADHD/I and a better understanding of its relation to ADHD/C are also presented. Specifically, investigators are encouraged to continue studying the complex interplay between inhibitory and attentional processes, as this area seems particularly promising in its ability to improve our understanding of the potentially distinct pathologies underlying the ADHD subtypes.
  • Thumbnail Image
    Item
    Interactive effects of drinking history and impulsivity on college drinking
    (Elsevier, 2013) Adams, Zachary W.; Milich, Richard; Lynam, Donald R.; Charnigo, Richard J.; Psychiatry, School of Medicine
    The transition from adolescence into emerging adulthood is a critical developmental period for changes in alcohol use and drinking related problems. Prior research has identified a number of distinct developmental alcohol use trajectories, which appear to be differentially related to young adult drinking outcomes. Another correlate of alcohol use in early adulthood is impulsivity. The primary aim of this study was to examine the moderating role of impulsivity in the relation between patterns of past alcohol use and hazardous drinking during the first year of college. Participants (N=452; 49% male; mean age 18.5years; 82% Caucasian) completed self-report measures during the first year of college, including retrospective alcohol use calendars, current alcohol use and drinking problems, and personality. Group-based trajectory modeling was used to identify groups with similar adolescent drinking history from retrospective, self-report. Four groups were identified: abstainers/very light users, late/moderate users, early/moderate users, and steep increase/heavy users. The abstainer/very light user group reported the lowest levels of alcohol use and problematic drinking in college; the steep increase/heavy use group reported the highest levels of alcohol use and problematic drinking. As predicted, the role of personality-specifically urgency, or emotion-based rash action-was strongest among moderate use groups. These findings may be helpful in guiding targeted prevention and intervention programs for alcohol use and abuse.
  • Thumbnail Image
    Item
    Specific Dimensions of Impulsivity Are Differentially Associated with Daily and Non-Daily Cigarette Smoking in Young Adults
    (Elsevier, 2015) Lee, Dustin C.; Peters, Jessica R.; Adams, Zachary W.; Milich, Richard; Lynam, Donald R.; Psychiatry, School of Medicine
    Young adults are at risk for initiation of tobacco use and progression to tobacco dependence. Not every person who smokes cigarettes becomes tobacco dependent, however, and non-daily smoking is becoming more prevalent among those who use tobacco. It is likely that individual differences in psychosocial and behavioral factors influence risk for engaging in non-daily and daily cigarette smoking. The objective of this study was to investigate the associations between impulsivity and smoking status in young adults who vary in frequency of cigarette smoking. Young adult first-year college students between the ages of 18-24 (512) were classified to one of three groups: non-smokers, non-daily smokers, or daily smokers, and impulsivity was assessed using the UPPS-P (negative and positive urgency, lack of premeditation, lack of perseverance, sensation seeking). When all impulsivity dimensions were used simultaneously to predict smoking status, negative urgency predicted increased risk of membership in the daily smoking group and lack of premeditation predicted increased risk of membership in the non-daily smoking group. These results suggest that dimensions of impulsivity may contribute differentially to forms of smoking behavior in young adults.
  • Thumbnail Image
    Item
    Substance Use Trajectories From Early Adolescence Through the Transition to College
    (Rutgers, 2016) Derefinko, Karen J.; Charnigo, Richard J.; Peters, Jessica R.; Adams, Zachary W.; Milich, Richard; Lynam, Donald R.; Psychiatry, School of Medicine
    Objective: The transition to college is an important developmental period for the development of alcohol, marijuana, and hard drug (cocaine, opiates, inhalants, stimulants, hallucinogens, Ecstasy, club drugs) use. The current study explored specific changes in substance use patterns during and after the transition to college through the use of trajectory analyses. Method: Participants were 526 students who reported retrospectively and prospectively on their substance use from age 13 through the junior year of college. Group-based trajectory modeling was used to estimate developmental trajectory groups for alcohol, marijuana, and hard drug use during this period. Results: Results supported a five-group model of alcohol use, a four-group model of marijuana use, and a four-group model of hard drug use. Although three of the five alcohol trajectories indicated high escalation throughout adolescence, one of these groups decreased in alcohol use dramatically during the freshman and sophomore years, a trend also found for hard drug use. Trajectories demonstrated significant differences in terms of gender, race, and impulsive personality characteristics. Conclusions: These results indicate that the start of college is an important developmental transition in terms of polysubstance use, and that despite the homogeneity of this undergraduate sample, there is considerable divergence in trajectories during college.
  • Thumbnail Image
    Item
    The Effect of Impulsivity and Drinking Motives on Alcohol Outcomes in College Students: A 3-year Longitudinal Analysis
    (Taylor & Francis, 2022) Fisher, Sycarah; Hsu, Wei-Wen; Adams, Zachary; Arsenault, Chelsea; Milich, Richard; Psychiatry, School of Medicine
    Objective: Substance use is a public health concern and cross-sectional studies have found that impulsivity and drinking motives influence substance use in emerging adults. Despite these findings, longitudinal studies with nuanced measures of impulsivity and drinking motives are needed. Participants: The current study investigated the three-year relationship between impulsivity-related traits, drinking motives, sex, and drinking outcomes in a sample of 509 college students (47.47% male; 81% White). Methods: The effects of impulsivity traits and drinking motives on problematic drinking outcomes were evaluated using linear mixed effects models. Results: The results confirmed the hypothesized relationship between traits of impulsivity, drinking motives, and alcohol outcomes over time. Further, sex significantly interacted with drinking motives longitudinally in its relationship with alcohol use outcomes. Conclusions: These results indicate that intervention efforts may need to be tailored to specific individual attributes to target direct correlates of alcohol use behavior to increase effectiveness.