Bergljot Gyda Gudmundsdottir

Misuse of prescription stimulants among college students: a review of the literature and implications for morphological and cognitive effects on brain functioning.

Prescription stimulant medication, the most frequently recommended treatment for college students with attention deficit/hyperactivity disorder (ADHD), has become increasingly available on college campuses. Research investigating prescription stimulant misuse among college students indicates that significant numbers of students without ADHD are taking prescription stimulants to enhance their cognitive performance. This article systematically reviews studies concerning misuse of prescription stimulants among college students with and without ADHD as well as the cognitive and morphological brain changes associated with prescription stimulants in humans and other animals. Whether these morphological changes are accompanied by improved cognitive performance remains equivocal. Implications of this body of literature are discussed and suggestions for future research are advanced.

Pharmacological interventions for adolescents and adults with ADHD: stimulant and nonstimulant medications and misuse of prescription stimulants

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by symptoms of inattention, hyperactivity, and impulsivity that cause functional impairment. Recent research indicates that symptoms persist into adulthood in the majority of cases, with prevalence estimates of approximately 5% in the school age population and 2.5%–4% in the adult population. Although students with ADHD are at greater risk for academic underachievement and psychosocial problems, increasing numbers of students with ADHD are graduating from high school and pursuing higher education. Stimulant medications are considered the first line of pharmacotherapy for individuals with ADHD, including college students. Although preliminary evidence indicates that prescription stimulants are safe and effective for college students with ADHD when used as prescribed, very few controlled studies have been conducted concerning the efficacy of prescription stimulants with college students. In addition, misuse of prescription stimulants has become a serious problem on college campuses across the US and has been recently documented in other countries as well. The purpose of the present systematic review was to investigate the efficacy of prescription stimulants for adolescents and young adults with ADHD and the nonmedical use and misuse of prescription stimulants. Results revealed that both prostimulant and stimulant medications, including lisdexamfetamine dimesylate, methylphenidate, amphetamines, and mixed-amphetamine salts, are effective at reducing ADHD symptoms in adolescents and adults with ADHD. Findings also suggest that individuals with ADHD may have higher rates of stimulant misuse than individuals without the disorder, and characteristics such as sex, race, use of illicit drugs, and academic performance are associated with misuse of stimulant medications. Results also indicate that individuals both with and without ADHD are more likely to misuse short-acting agents than long-acting agents. These findings have implications for intervention, prevention, and future research.

Neuroimaging and ADHD: fMRI, PET, DTI Findings, and Methodological Limitations

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by pervasive and developmentally inappropriate levels of inattention, impulsivity, and hyperactivity. There is no conclusive cause of ADHD although a number of etiologic theories have been advanced. Research across neuroanatomical, neurochemical, and genetic disciplines collectively support a physiological basis for ADHD and, within the past decade, the number of neuroimaging studies concerning ADHD has increased exponentially. The current selective review summarizes research findings concerning ADHD using functional magnetic resonance imaging (fMRI), positron emission tomography (PET), and diffusion tensor imaging (DTI). Although these technologies and studies offer promise in helping to better understand the physiologic underpinnings of ADHD, they are not without methodological problems, including inadequate sensitivity and specificity for psychiatric disorders. Consequently, neuroimaging technology, in its current state of development, should not be used to inform clinical practice.

Rates and Patterns of Comorbidity Among First-Year College Students With ADHD

The purpose of this study was to examine rates and patterns of non–attention-deficit/hyperactivity disorder (non-ADHD) psychiatric diagnoses among a large group of 1st-year college students with and without ADHD. A total of 443 participants, including 214 men and 229 women ranging in age from 18 to 22 years of age (M = 18.2), were recruited from 9 colleges involved in a large-scale, multisite longitudinal investigation. Non-Hispanic Caucasian students represented 67.5% of the total sample. A comprehensive multimethod assessment approach was used in conjunction with expert panel review to determine both ADHD and comorbidity status. Significantly higher rates of overall comorbidity were found among college students with well-defined ADHD, with 55.0% exhibiting at least one comorbid diagnosis and 31.8% displaying two or more, relative to the corresponding rates of non-ADHD diagnoses among Comparison students, which were 11.2% and 4.0%, respectively. These differences in overall comorbidity rates were, in large part, attributable to the increased presence of depressive and anxiety disorders, especially major depressive disorder (active or in partial remission) and generalized anxiety disorder, among the students with ADHD. Within the ADHD group, differential comorbidity rates were observed as a function of ADHD presentation type and gender but not ethnic/racial diversity status. The current findings fill a gap in the literature and shed new light on the rates and patterns of comorbidity among emerging adults with ADHD in their 1st year of college. Implications for providing clinical and support services to college students with ADHD are discussed.

Neurocognitive enhancement or impairment? A systematic meta-analysis of prescription stimulant effects on processing speed, decision-making, planning, and cognitive perseveration.

Increasing numbers of adults, particularly college students, are misusing prescription stimulants primarily for cognitive/academic enhancement, so it is critical to explore whether empirical findings support neurocognitive benefits of prescription stimulants. Previous meta-analytic studies have supported small benefits from prescription stimulants for the cognitive domains of inhibitory control and memory; however, no meta-analytic studies have examined the effects on processing speed or the potential impairment on other domains of cognition, including planning, decision-making, and cognitive perseveration. Therefore, the present study conducted a meta-analysis of the available literature examining the effects of prescription stimulants on specific measures of processing speed, planning, decision-making, and cognitive perseveration among healthy adult populations. The meta-analysis results indicated a positive influence of prescription stimulant medication on processing speed accuracy, with an overall mean effect size of g = 0.282 (95% CI [0.077, 0.488]; n = 345). Neither improvements nor impairments were revealed for planning time, planning accuracy, advantageous decision-making, or cognitive perseveration; however, findings are limited by the small number of studies examining these outcomes. Findings support that prescription stimulant medication may indeed act as a neurocognitive enhancer for accuracy measures of processing speed without impeding other areas of cognition. Considering that adults are already engaging in illegal use of prescription stimulants for academic enhancement, as well as the potential for stimulant misuse to have serious side effects, the establishment of public policies informed by interdisciplinary research surrounding this issue, whether restrictive or liberal, is of critical importance. (PsycINFO Database Record

Neuropsychological functioning in college students with and without ADHD.

Objective: Increasing numbers of students with attention-deficit/hyperactivity disorder (ADHD) are attending college; however, little empirical information is available concerning the functional impairment experienced by these students. Although preliminary studies suggest that college students with ADHD are more likely to experience a variety of psychosocial and academic difficulties compared to their peers without the disorder, findings regarding neuropsychological functioning have been inconsistent with some studies reporting that college students with ADHD perform more poorly on various cognitive and neuropsychological tasks while others report no differences compared to their peers without ADHD. Method: The purposes of the present study, the Trajectories Related to ADHD in College project, a longitudinal study following the 4-year outcomes of college students with and without ADHD, were to (a) examine the performance of 436 first-year college students with and without ADHD (51.6% female) on measures of executive function (EF) and intelligence and (b) investigate the association of self-reported use of stimulant medication and neuropsychological performance in students with ADHD. Participant data from their first year of involvement in the study were analyzed. Results: Participants with ADHD performed more poorly on task-based and self-report EF measures relative to the comparison group. In contrast, no significant group differences were found with respect to intellectual performance. Within the ADHD group, use of prescription stimulant medication was associated with improved performance on some, but not all, neuropsychological tasks. Additional analyses also revealed significant group differences in EF based on clinical diagnostic status. Conclusion: College students with ADHD demonstrated poorer EF than their peers without ADHD and psychostimulant medication was associated with improved EF performance. No group differences were found with respect to intellectual functioning, Lastly, having one or more comorbid psychiatric diagnoses in addition to ADHD was associated with poorer EF outcomes.

Prescription stimulant medication misuse: Where are we and where do we go from here?

Prescription stimulants, including methylphenidate (e.g., Ritalin) and amphetamine compounds (e.g., dextroamphetamine; Adderall), have been approved by the U.S. Food and Drug Administration for the treatment of attention-deficit/hyperactivity disorder (ADHD) and are classified by the United States Drug Enforcement Administration as Schedule II medications because of their high potential for abuse and dependence (Drug Enforcement Administration, U.S. Department of Justice, 2015). Despite the potential health and judicial consequences, misuse of prescription stimulants, typically defined as taking stimulants without a valid prescription, or use of stimulants other than as prescribed, has become a serious problem in the United States and abroad, especially on college campuses. The purpose of the present article is to review historical information concerning prescription stimulants and to summarize the literature with respect to misuse among adults, particularly college students, including risk factors, mediators and moderators, and motivations for prescription stimulant misuse. In addition, evidence is presented concerning the question of whether prescription stimulants truly enhance cognitive functioning in individuals with and without ADHD, and the ethical and professional implications of these findings are explored. Lastly, recommendations for addressing prescription stimulant misuse and suggestions for future research are advanced. (PsycINFO Database Record

Physiological substrates of executive functioning: a systematic review of the literature

Executive function (EF) is a multifaceted construct that has been defined as a set of higher-order cognitive processes that allow for flexibility, self-regulation, strategic planning, and goal-directed behaviors. EFs have been studied in numerous clinical disorders using a variety of neuropsychological tasks and, more recently, neuroimaging techniques. The underlying physiological substrates of EF were historically attributed to the frontal lobes; however, recent studies suggest more widespread involvement of additional brain regions. The purpose of the present study was to conduct a systematic review (using PRISMA 2009 guidelines) of neuroimaging studies employing functional magnetic resonance imaging and diffusion tensor imaging methods investigating the physiological substrates of EFs in attention-deficit/hyperactivity disorder compared to other clinical groups and non-clinical participants. Research articles were retrieved using PsycINFO, PsycARTICLES, MEDLINE, and ScienceDirect, beginning February 2015 through May 2016. A total of 42 studies met eligibility. Of those 42 studies, 22 studies included clinical participants and 20 studies included non-clinical participants. Results revealed increased activation of the frontal brain region in the majority of non-clinical studies and approximately 50% of the clinical studies, albeit with some inconsistencies across subregions, tasks, and age groups. Implications, methodological limitations, and suggestions for future research are discussed.

Prescription stimulant misuse and ADHD symptomatology among college students in Iceland

Objective: Misuse of prescription stimulant medication is a prevalent problem on American college campuses; however, few studies have been conducted beyond the United States. Although Iceland has the highest methylphenidate prescription rates in the world, prevalence of stimulant misuse within the Icelandic college student population remains to be investigated. Method: We examined the prevalence of prescription stimulant misuse among N = 521 college students in Iceland, using an online survey. Results: Overall prevalence of lifetime stimulant misuse was approximately 13%; 11% among participants without a prescription for stimulant medication, and 42% among participants holding a prescription. The primary reported reason for misuse was academic enhancement; risk factors included male sex, anxiety symptoms, and ADHD symptomatology. Conclusion: The present findings have implications for public health policy in Iceland, particularly as it relates to the college population. Prevention and intervention programs that provide college students with safer strategies to manage academic demands are warranted.

Neurocognitive, Autonomic, and Mood Effects of Adderall: A Pilot Study of Healthy College Students

Prescription stimulant medications are considered a safe and long-term effective treatment for Attention Deficit Hyperactivity Disorder (ADHD). Studies support that stimulants enhance attention, memory, self-regulation and executive function in individuals with ADHD. Recent research, however, has found that many college students without ADHD report misusing prescription stimulants, primarily to enhance their cognitive abilities. This practice raises the question whether stimulants actually enhance cognitive functioning in college students without ADHD. We investigated the effects of mixed-salts amphetamine (i.e., Adderall, 30 mg) on cognitive, autonomic and emotional functioning in a pilot sample of healthy college students without ADHD (n = 13), using a double-blind, placebo-controlled, within-subjects design. The present study was the first to explore cognitive effects in conjunction with mood, autonomic effects, and self-perceptions of cognitive enhancement. Results revealed that Adderall had minimal, but mixed, effects on cognitive processes relevant to neurocognitive enhancement (small effects), and substantial effects on autonomic responses, subjective drug experiences, and positive states of activated emotion (large effects). Overall, the present findings indicate dissociation between the effects of Adderall on activation and neurocognition, and more importantly, contrary to common belief, Adderall had little impact on neurocognitive performance in healthy college students. Given the pilot design of the study and small sample size these findings should be interpreted cautiously. The results have implications for future studies and the education of healthy college students and adults who commonly use Adderall to enhance neurocognition.