Comorbidity of ADHD and Substance Use Disorder (SUD): a neuroimaging perspective

ADHD: prevalence and effect on opioid use disorder treatment outcome in a French sample of patients receiving medication for opioid use disorder-the influence of impulsivity as a mediating factor

BACKGROUND

Opioid use disorder (OUD) poses a global health challenge, and despite medications for opioid use disorder (MOUD) and psychosocial interventions, relapse remains a significant concern. Comorbid psychiatric disorders, including attention deficit hyperactivity disorder (ADHD), are one of the major factors associated with poor OUD treatment outcome. We aimed to estimate the frequency of probable ADHD (in childhood and in adulthood) in patients with OUD; to assess the factors associated with this comorbidity; and to explore the factors that mediate the relationship between ADHD and OUD treatment outcome.

METHODS

We conducted an observational study using a sample of 229 patients aged 18 years and older who were diagnosed with OUD and had received MOUD for at least six months. Participants were assessed through a structured interview and self-report questionnaires. Multivariate logistic regressions and a mediation analysis were performed.

RESULTS

Almost half of the participants reported probable ADHD in childhood, and ADHD persisted into adulthood among two-thirds of the patients. The factors associated with poor OUD treatment outcome included earlier onset of OUD, lower education, and greater impulsivity. There was no direct effect of probable ADHD in childhood on OUD treatment outcome, but there was an indirect effect through negative urgency, the tendency to respond impulsively to negatively connoted emotional experiences.

CONCLUSIONS

The findings suggest that ADHD symptoms, particularly impulsivity, may contribute to vulnerability in opioid use and play a crucial role in treatment outcomes for this population.

TRIAL REGISTRATION

ClinicalTrials identifier NCT01847729.

Criminal convictions in males and females diagnosed with attention deficit hyperactivity disorder: A Swedish national registry study

Background

Individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) face an elevated risk of criminal convictions compared to those without ADHD. However, understanding this link involves considering sex differences, coexisting psychiatric conditions, and unmeasured familial factors. This study aimed to explore the connection between ADHD and criminal convictions (both violent and non-violent) in males and females, while also assessing the impact of comorbid psychiatric disorders and familial factors.

Methods

Using Swedish national registers, we identified individuals born between 1986 and 1997 (635,391 males and 600,548 females). ADHD was defined through clinical diagnosis and prescribed medications, while criminal convictions were determined based on Swedish lower court records. Unmeasured familial factors were accounted for using a sibling design approach.

Results

Findings revealed that individuals with ADHD had a notably higher absolute and relative risk of both violent and non-violent criminal convictions compared to those without ADHD. While criminal convictions were more frequent among males with ADHD, females with ADHD exhibited higher relative risks (HR violent 10.50, non-violent 4.04) than their male counterparts (HR violent 6.03, non-violent 3.57). Additionally, lower socioeconomic status (SES) in individuals with ADHD was associated with increased relative risks for criminal convictions compared to individuals with ADHD who had higher SES. Adjusting for childhood and internalizing psychiatric disorders partially attenuated these associations, while substance use disorders (SUD) substantially attenuated them. SUD also contributed to an elevated absolute risk of criminal convictions in both male and female individuals with ADHD. Accounting for unmeasured shared familial factors slightly reduced the estimates, but the association between ADHD and criminal convictions persisted.

Conclusion

In conclusion, ADHD remains a potent independent risk factor for criminal convictions, with varying effects based on gender. This underscores the importance of tailored crime prevention strategies and early interventions for individuals with ADHD, especially when comorbid SUD is present.

The HINT1 Gene rs2526303 Polymorphism and Its Association with Personality Traits in Cigarette Smokers

The development of a substance use disorder (SUD) is a multifaceted process influenced by both genetic and environmental factors. Recent research has suggested the potential involvement of the HINT1 gene in various aspects of plasticity, mood regulation, anxiety-like behaviour, and stress-coping mechanisms. Moreover, personality traits are also recognised to be instrumental in developing substance dependency. Given these considerations, our study investigated the associations among cigarette smoking, personality traits, and the rs2526303 polymorphism. Additionally, we investigated the interactions between personality traits and rs2526303 in the HINT1 gene. The study group comprised 531 volunteers: 375 cigarette users (mean age = 29.42 ± 10.72; F = 49%, M = 51%) and 156 never-smokers (mean age = 26.93 ± 10.09; F = 79%, M = 21%). Genotyping was conducted using the real-time PCR method, and the NEO Five-Factor Personality Inventory and State-Trait Anxiety Inventory were administered. There were no statistically significant differences in the frequency of rs2526303 genotypes and alleles in the cigarette user group compared to the control group. Compared to the control group, the cigarette users obtained higher scores in the assessment of the NEO-FFI Extraversion scale and lower results for the NEO-FFI Openness, Agreeableness, and Conscientiousness scales. Additionally, there was a statistically significant effect of rs2526303 genotype interaction and cigarette-using status on the conscientiousness scale. These outcomes collectively suggest a notable association between cigarette smoking and specific dimensions of personality, particularly highlighting differences in extraversion, openness, agreeableness, and conscientiousness. Furthermore, the detected interaction effect involving rs2526303 concerning conscientiousness signifies a complex interplay between genetic factors and smoking behaviour.

Interval timing relative to response inhibition in the differential reinforcement of low-rate responding in normally developing young adults

With recent proposal suggesting the multifaceted nature of impulsivity, researchers have been intrigued by the question of whether the impulsive behaviour measured in the traditionally psychological paradigms is unitary. One such paradigm, the differential reinforcement of low-rate responding (DRL), has been used to assess response inhibition, but its underlying mechanism has still been debated. In present research, we examined and differentiated the effects of both response inhibition and interval timing on a multisession DRL-10 s (DRL-10 s) in a large sample of normally developing young adults, as well as with three other measures including the stop-signal reaction task (SSRT), time production task-10 s (TPT-10 s), and the Barrett impulsivity scale-11 (BIS-11). The results showed that behavioural changes existed in DRL. As the task sessions progressed, there was an increase in both reinforcement probability and peak time, but a decrease in burst responses. Most importantly, both principal component analysis and generalized multilevel modeling yielded consistent results that as the task progressed, there was an increasing involvement of the TPT in the late sessions of DRL. However, none of the effect of SSRT was found. In sum, the differential degrees of involvement of the timing process, relative to response inhibition, were observed in DRL.

Effects of emotional working memory training on problematic internet use, inhibition, attention, and working memory among young problematic internet users: A randomized control study

Problematic internet use (PIU) has been defined as an inability to control impulses to use the internet, and is associated with psychological, social, educational, and/or occupational problems. Considering the harmful effects of PIU, the present study evaluated a treatment intervention aimed at controlling PIU. A randomized control study investigated the effectiveness of emotional working memory training (eWMT) in improving inhibition, attention, and working memory among individuals with PIU in comparison with a placebo group. Young adults (N = 36) with PIU were either trained for 20 sessions in an n-back dual emotional task (eWMT; n = 18) or a feature matching task (placebo; n = 18). Results showed that 20 continuous sessions of eWMT significantly reduced the symptoms of PIU and improved participants' working memory, attention, and inhibition (compared to the placebo group). These preliminary findings suggest that eWMT can be considered a promising treatment to reduce PIU by improving individuals' cognitive and emotional functioning.

Diagnostic Dilemma of Differentiating Attention-Deficit/Hyperactivity Disorder (ADHD) From Mood Disorders and Other Common Psychiatric Illnesses in Substance Use Patient Population

To raise awareness of attention-deficit/hyperactivity disorder (ADHD) as an underdiagnosed, undertreated disorder in adult patients with comorbid substance use disorder (SUD) who are misdiagnosed with other common psychiatric illnesses and to reduce fear and hesitancy in prescribing stimulants as treatment in such a patient population. ADHD diagnosis is easier in the child and adolescent population than the adults due to comorbidities of other psychiatric illnesses and SUD. However, diagnosing ADHD appropriately in an increasing number of adult patients presents challenges. Even if they get diagnosed appropriately, the stigma of substance use disorder holds the providers prescribing stimulant medications for such patient populations due to the high comorbidity of ADHD with SUD. Accurate diagnosis of ADHD in adults is a worthwhile endeavor as this diagnosis is comorbidly present in many mood and substance use disorders patients. Treating ADHD in this population can improve clinical symptoms and overall quality of life.

The propensity to sign-track is associated with externalizing behavior and distinct patterns of reward-related brain activation in youth

Externalizing behaviors in childhood often predict impulse control disorders in adulthood; however, the underlying bio-behavioral risk factors are incompletely understood. In animals, the propensity to sign-track, or the degree to which incentive motivational value is attributed to reward cues, is associated with externalizing-type behaviors and deficits in executive control. Using a Pavlovian conditioned approach paradigm, we quantified sign-tracking in 40 healthy 9-12-year-olds. We also measured parent-reported externalizing behaviors and anticipatory neural activations to outcome-predicting cues using the monetary incentive delay fMRI task. Sign-tracking was associated with attentional and inhibitory control deficits and the degree of amygdala, but not cortical, activation during reward anticipation. These findings support the hypothesis that youth with a propensity to sign-track are prone to externalizing tendencies, with an over-reliance on subcortical cue-reactive brain systems. This research highlights sign-tracking as a promising experimental approach delineating the behavioral and neural circuitry of individuals at risk for externalizing disorders.

Structural differences among children, adolescents, and adults with attention-deficit/hyperactivity disorder and abnormal Granger causality of the right pallidum and whole-brain

Attention-deficit/hyperactivity disorder (ADHD) is a childhood mental health disorder that often persists to adulthood and is characterized by inattentive, hyperactive, or impulsive behaviors. This study investigated structural and effective connectivity differences through voxel-based morphometry (VBM) and Granger causality analysis (GCA) across child, adolescent, and adult ADHD patients. Structural and functional MRI data consisting of 35 children (8.64 ± 0.81 years), 40 adolescents (14.11 ± 1.83 years), and 39 adults (31.59 ± 10.13 years) was obtained from New York University Child Study Center for the ADHD-200 and UCLA dataset. Structural differences in the bilateral pallidum, bilateral thalamus, bilateral insula, superior temporal cortex, and the right cerebellum were observed among the three ADHD groups. The right pallidum was positively correlated with disease severity. The right pallidum as a seed precedes and granger causes the right middle occipital cortex, bilateral fusiform, left postcentral gyrus, left paracentral lobule, left amygdala, and right cerebellum. Also, the anterior cingulate cortex, prefrontal cortex, left cerebellum, left putamen, left caudate, bilateral superior temporal pole, middle cingulate cortex, right precentral gyrus, and the left supplementary motor area demonstrated causal effects on the seed region. In general, this study showed the structural differences and the effective connectivity of the right pallidum amongst the three ADHD age groups. Our work also highlights the evidence of the frontal-striatal-cerebellar circuits in ADHD and provides new insights into the effective connectivity of the right pallidum and the pathophysiology of ADHD. Our results further demonstrated that GCA could effectively explore the interregional causal relationship between abnormal regions in ADHD.

Personality and substance use disorder: Characteristics as measured by NEO-personality inventory–revised

The present study investigates the personality characteristics of a cohort of patients with Substance Use Disorders. The included participants (n = 123) were recruited from specialized treatment for addictions in Norway. The personality scores in the current sample were compared to the Norwegian norm sample with t-tests. Age and gender differences in personality scores were assessed by bivariate correlation analyses and t-tests, respectively. The sample had higher scores on Neuroticism and lower scores on Conscientiousness, Agreeableness, Extraversion, and Openness compared to the norm sample (p < 0.01). The effect sizes of the differences between the current sample and the Norwegian norm sample were large for Neuroticism and Conscientiousness. Older participants scored higher on Agreeableness and its facets A1: Trust and A2: Straightforwardness and lower on the facet E5: Excitement-Seeking (p < 0.01). No significant (p < 0.01) gender differences in NEO-PI-R scores were found. In conclusion, the current results support previous findings regarding personality traits associated with SUD. The clinical relevance of the findings is discussed.

Persistent Deficits in Self-Regulation as a Mediator between Childhood Attention-Deficit/Hyperactivity Disorder Symptoms and Substance Use Disorders

The link between attention-deficit/hyperactivity disorder (ADHD) and substance use disorders (SUDs) has been largely demonstrated. Some scholars have hypothesized that self-regulation mechanisms might play a key role in explaining this association. Objective(s): The current study tested the hypothesis that retrospective childhood ADHD symptoms might lead to more severe SUDs and this association should be mediated by current self-ratings of behavioral disinhibition, inattention, and emotional dysregulation among 204 treatment-seeking adults (male: 67.3%; female: 32.7%) with a primary diagnosis of alcohol use disorder and other SUDs. Methods: The mediational model was estimated through self-report measures of childhood ADHD symptoms (independent variable; WURS), current self-regulation mechanisms (mediators)-behavioral disinhibition (BIS-11 motor subscale), difficulties with attention regulation (MAAS) and emotion regulation (DERS)-and severity of SUDs (dependent variable; SPQ alcohol, illicit and prescribed drugs). Results: The analysis showed that alterations in the self-regulation system fully mediated the association between the severity of childhood ADHD symptoms and SUDs in adulthood. Behavioral disinhibition and difficulties in attention regulation were the most representative alterations in self-regulation processes that explained this association. Conclusions: These findings suggest it is useful to implement several therapeutic approaches (e.g. behavioral, mindfulness-based, and pharmacological) to increase the self-regulation abilities of children and adolescents with ADHD in order to reduce the probability of SUD onset in adulthood. However, future longitudinal neuroimaging and neuropsychological studies are needed to further support the role of self-regulation mechanisms in explaining the prospective association between childhood ADHD symptoms and SUDs in adulthood.

Lifetime depressive and current social anxiety are associated with problematic internet use in adolescents with ADHD: a cross-sectional study

AIM

To evaluate the relationships between problematic internet use (PIU) and psychiatric comorbid disorders and internet use habits in a clinical sample of adolescents with attention-deficit/hyperactivity disorder (ADHD).

METHOD

This cross-sectional study included 95 adolescents with ADHD. Problematic behaviors and symptoms related to internet use were evaluated via Young's Internet Addiction Scale (YIAS), and subjects with a YIAS score of ≥50 were categorized as PIU while those with a score of <50 were defined as normal internet use (NIU). The two groups were compared with respect to demographics and psychometric tests. While psychiatric disorders were examined by a semistructured instrument, self-report and parent-report scales were used to assess other individual and clinical characteristics of participants.

RESULTS

33.7% (n = 32) of the participants were determined to have PIU. There was no gender (p = .058) or age (p = .426) difference between the PIU and NIU groups. Current presence of social phobia (p = .035) and history of major depressive disorder (p = .006) were more frequent in the PIU group than the NIU group. Multivariable regression analysis revealed that PIU was independently associated with online gaming (OR: 2.375, 95% CI: 1.532-3.681), e-mail use (OR: 1.864, 95% CI: 1.170-2.971), social networking (OR: 1.834, 95% CI: 1.156-2.910), and Social Phobia Scale for Children and Adolescents (SPSCA) score (OR: 1.058, 95% CI: 1.020-1.098).

CONCLUSION

PIU may be common among adolescents with ADHD. The severity of social phobia and particular online activities (playing online games, e-mailing, social networking) may be associated with a higher risk of PIU in adolescents with ADHD.

Neural networks during delay discounting as trans-disease marker: A meta-analytical review

Delay discounting reflects a devaluation of delayed long-term benefits but pursuing immediate rewards. Higher discounting rates (h-DR) are found ubiquitous in many diseases and unhealthy conditions, particularly in addiction disorder (AD), attention-deficit/hyperactivity disorder (ADHD), and obesity. Thus, h-DR was considered to be a common benchmark across many diseases facilitating to understand one disease to relevant others, which was called trans-disease process. However, the common and specific neural biomarkers associated with this process has not yet been studied well. We performed a voxel-wise task-related neuroimaging meta-analysis to clarify the neural pattern of trans-disease process across AD, ADHD and obesity. We recruited 19 eligible papers, including 9 AD papers (154 patients), 6 ADHD papers (106 patients) and 4 obesity studies (94 patients). Neuroimaging meta-analysis demonstrated the presence of neural biomarkers of trans-disease process: these patients showed inadequate brain response in caudate, ventromedial and dorsolateral prefrontal cortex (dlPFC) than do of healthy controls (HCs). Disease-specific neural patterns were also found, with prominent hypoactivation in parahippocampal-striatum network for AD, hyperactivation in dopamine-projection striatum network for ADHD and decreased activity in dorsal anterior cingulate cortex and dlPFC for obesity. This study provided robust evidence to reveal the neural substrates of trans-disease process, as well further promoted the triple brain network model in favor of the theoretical developments of these neuropsychiatric disorders.

ASRS Questionnaire and Tobacco Use: Not Just a Cigarette. A Screening Study in an Italian Young Adult Sample

Young adults exhibit greater sensitivity than adults to nicotine reinforcement, and Attention Deficit Hyperactivity Disorder (ADHD) increases the risk for early-onset smoking. We investigated the correlation between ADHD Self-Report Scale (ASRS) scores and smoking, evaluated the prevalence of ADHD symptomatology (not diagnoses) in smokers and non-smokers and its comorbidity with benzodiazepine and gambling addictions. A total of 389 young adults from 14 schools in Northern Italy fill out a survey and the Adult ADHD Self-Report Scale (ASRS). A total of 15.2% of subjects tested positive at the ASRS, which correlated with smoking; moreover, smokers had twice the probability of testing positive at the ASRS. ADHD symptomatology, especially when comorbid with tobacco abuse, is an important condition to monitor because early nicotine exposure could be a gateway for other addictive behaviors.

Stop What You're Doing!-An fMRI Study on Comparisons of Neural Subprocesses of Response Inhibition in ADHD and Alcohol Use Disorder

Rationale: Both attention deficit-/hyperactivity disorder (ADHD) and alcohol use disorder (AUD) are accompanied by deficits in response inhibition. Furthermore, the prevalence of comorbidity of ADHD and AUD is high. However, there is a lack of research on whether the same neuronal subprocesses of inhibition (i.e., interference inhibition, action withholding and action cancellation) exhibit deficits in both psychiatric disorders. Methods: We examined these three neural subprocesses of response inhibition in patient groups and healthy controls: non-medicated individuals with ADHD (ADHD; N = 16), recently detoxified and abstinent individuals with alcohol use disorder (AUD; N = 15), and healthy controls (HC; N = 15). A hybrid response inhibition task covering interference inhibition, action withholding, and action cancellation was applied using a 3T functional magnetic resonance imaging (fMRI). Results: Individuals with ADHD showed an overall stronger hypoactivation in attention related brain areas compared to AUD or HC during action withholding. Further, this hypoactivation was more accentuated during action cancellation. Individuals with AUD recruited a broader network, including the striatum, compared to HC during action withholding. During action cancellation, however, they showed hypoactivation in motor regions. Additionally, specific neural activation profiles regarding group and subprocess became apparent. Conclusions: Even though deficits in response inhibition are related to both ADHD and AUD, neural activation and recruited networks during response inhibition differ regarding both neuronal subprocesses and examined groups. While a replication of this study is needed in a larger sample, the results suggest that tasks have to be carefully selected when examining neural activation patterns of response inhibition either in research on various psychiatric disorders or transdiagnostic questions.

Aberrant structural network of comorbid attention deficit/hyperactivity disorder is associated with addiction severity in internet gaming disorder

BACKGROUND

Internet gaming disorder (IGD) is commonly comorbid with attention-deficit/hyperactivity disorder (ADHD). Although the addiction is more severe when comorbid with ADHD, little is known about the neural correlates of the association. This study aimed to identify whether an ADHD-related structural brain network exists in IGD patients with comorbid ADHD (IGDADHD+) by comparing them with those without comorbid ADHD (IGDADHD-) and elucidating how the sub-network is associated with addiction severity.

METHODS

Brain structural networks were constructed based on streamline tractography with diffusion tensor imaging in a cohort of 46 male IGDADHD+ patients, 48 male IGDADHD- patients, and 34 healthy controls (HC). We used network-based statistics (NBS) to identify the sub-network differences between the two IGD groups. Furthermore, the edges in the sub-network that significantly contributed to explaining the Young Internet Addiction Scale (YIAS) score were delineated using partial least square (PLS) regression analyses in IGD patients.

RESULTS

The YIAS score was higher in the IGDADHD+ group than in the IGDADHD- group and was correlated with the Korean Dupaul's ADHD scale score (r = 0.42, p <0.01). The NBS detected a sub-network with stronger connectivity in the IGDADHD+ group than in the IGDADHD-group. The PLS regression model showed that the sub-network is associated with the YIAS score in the IGDADHD+ group (q2 = 0.019). Edges connecting the left pre- and postcentral gyri, bilateral superior frontal gyri, medial orbital parts, and left fusiform to the inferior temporal gyrus were most important predictors in the regression model.

CONCLUSION

Our results suggest that an aberrant increase in some structural connections within circuits related to inhibitory function or sensory integration can indicate how comorbid ADHD is associated with addiction severity in IGD.

Mapping sign-tracking and goal-tracking onto human behaviors

As evidenced through classic Pavlovian learning mechanisms, environmental cues can become incentivized and influence behavior. These stimulus-outcome associations are relevant in everyday life but may be particularly important for the development of impulse control disorders including addiction. Rodent studies have elucidated specific learning profiles termed 'sign-tracking' and 'goal-tracking' which map onto individual differences in impulsivity and other behaviors associated with impulse control disorders' etiology, course, and relapse. Whereas goal-trackers are biased toward the outcome, sign-trackers fixate on features that are associated with but not necessary for achieving an outcome; a pattern of behavior that often leads to escalation of reward-seeking that can be maladaptive. The vast majority of the sign- and goal-tracking research has been conducted using rodent models and very few have bridged this concept into the domain of human behavior. In this review, we discuss the attributes of sign- and goal-tracking profiles, how these are manifested neurobiologically, and how these distinct learning styles could be an important tool for clinical interventions in human addiction.

Methylphenidate for Attention-Deficit and Hyperactivity Disorder in Adult Patients With Substance Use Disorders: Good Clinical Practice

Attention-deficit and hyperactivity disorder (ADHD) is a widespread neurodevelopmental disorder in children and adolescents, persisting into adulthood in a majority of them. ADHD and substance use disorders (SUDs) commonly co-occur in the clinical adult population. The higher-than-normal prevalence rates of SUDs in people with ADHD indicate increased risk for developing SUD. This narrative review deals with the question of whether or not adults with both disorders should be treated with methylphenidate (MPH), addressing specific issues surrounding this form of treatment. MPH is considered as first-line pharmacotherapy for ADHD. However, because of its stimulant-like reinforcing properties, MPH has a significant addictive potential to which persons with SUDs are especially susceptible. Appropriate treatment is therefore complex. Because of concerns about misuse and diversion of MPH medication, clinicians may be reluctant to use MPH to manage ADHD symptoms in these patients. However, it is essential to diagnose and treat ADHD adequately as appropriate therapy reduces the impairments, as well as the risk of developing comorbid disorders and poor treatment response. MPH should not be deprived of these patients because of the risk for misuse, especially as several strategies can be applied to minimize this risk. To conclude, carefully applied guideline-based diagnostics to clarify the potential presence of ADHD as well as a responsible prescription practice in a well-defined therapeutic setting with reliable monitoring of medication intake and regular consultations are essential conditions for a safe and proficient MPH treatment of ADHD in patients with SUD.

Craving for heroin: difference between methadone maintenance therapy patients with and without ADHD

INTRODUCTION

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder persisting in adulthood in 40-60% of cases. Clinical and neuroimaging studies suggest that patients affected by both drug addiction and ADHD show higher rates of craving for drug than patients without ADHD. We designed a pilot open-label study to investigate the effects of ADHD on craving for heroin in methadone maintenance therapy patients.

METHOD

Patients were recruited from outpatient facilities in an addiction treatment unit in the municipality of Alba, Italy. They were assessed using the Structured Clinical Interview for DSM-5 (SCID-5), the SCID-5 for Personality Disorders (SCID-5-PD), the Diagnostic Interview for Adult ADHD, second edition (DIVA 2.0), and the Clinical Opiate Withdrawal Scale (COWS). Categorical variables were examined using the chi-square test, and continuous variables, the t-test and Mann-Whitney's U test for normally and non-normally distributed data, respectively. Data distribution was evaluated using Shapiro-Wilk's test. Significance was set at p=0.05. Bonferroni correction was applied (0.0063) to avoid type I error.

RESULTS

A total of 104 patients were included in the study: 14 affected by ADHD (13.5%) and 90 were not affected (86.5%). Patients with ADHD showed higher intensity of craving for heroin than patients without ADHD in the absence of withdrawal symptoms.

CONCLUSION

Drug addiction and ADHD share various neurobiological mechanisms that mutually influence the evolution of both disorders. In particular, dopamine dysfunction within various brain circuits may influence impulsivity levels, motivation, inhibitory control, executive functions, and behavior and, consequently, the intensity of craving.

Risk taking behaviors in relation to Attention Deficit and Hyperactivity Disorder in Iranian male workers: a latent class analysis

BACKGROUND

Risk taking behaviors are a serious risk to the health and safety of workers. The aims of this study were to identify the subgroups of workers on the basis of risk taking behaviors and assess the independent role of ADHD on the membership of participants in each latent class.

METHODS

This cross sectional study was performed on 2434 workers. The sample was selected through random cluster sampling from Kaveh Industrial City. All workers completed five sets of checklists and questionnaires. Data analysis was performed using chi-square, Fisher's exact test, and latent class analysis.

RESULTS

Four latent classes were identified; namely, 1) very low risk (65.6%), 2) low risk (27.8%), moderate risk (4.1%) and, high risk (2.5%). After adjusting for other studied covariates, having ADHD significantly increased the odds of membership in moderate risk class (OR=3.42, 95% CI: 2.21 -5.29) and high risk class (OR=3.10, 95% CI: 1.80 -5.34) compared to very low risk class. Also, having anxiety increased the odds of membership in latent class 2 (OR=1.28, 95% CI: 1.02-1.62), 3(OR=2.15, 95% CI: 1.51-3.10) and 4 (OR=2.06, 95% CI: 1.32-3.22) in comparison to class 1. Among all participants, 187 (7.7%) had ADHD and among studied variables, ADHD has the strongest role in the membership of subjects in different classes.

CONCLUSION

Results from the present study indicate that 6.6% of the workers fell under moderate or high risk class. Focusing on the treatment of ADHD with considering other comorbid factors such as anxiety may be helpful in designing and executing effective programs to reduce risk taking behaviors among workers.

Diagnosing ADHD during active substance use: Feasible or flawed?

BACKGROUND

Attention Deficit Hyperactivity Disorder (ADHD) is highly prevalent in patients with a substance use disorder (SUD). Because of possible problems with validity, diagnostic assessment of ADHD is usually postponed until after a period of abstinence, which may jeopardize adequate and timely treatment. The aim of this study is to investigate how a diagnostic assessment of ADHD in patients who are actively using substances compares to the results of a second assessment after a period of full or partial abstinence.

METHODS

Prospective test-retest study in a SUD treatment center among 127 treatment seeking adult SUD patients with a comorbid diagnosis of adult ADHD. Conners' Adult ADHD Diagnostic Interview for DSM-IV was administered at intake and after four SUD treatment sessions.

RESULTS

The mean time interval between intake and retest assessment was 78days (SD=32; range 31-248). At the second ADHD assessment, substance use had decreased to about 50% of baseline consumption. Of the 127 patients with an initial diagnosis of ADHD, 121 patients (95.3%) still fulfilled DSM-IV adult ADHD criteria at re-diagnosis. Subtyping of ADHD was less stable (Cohen's Kappa=0.53). Agreement on the number of childhood and adult ADHD symptoms between both assessments was good (intraclass correlation coefficient of 0.69 and 0.65, respectively). Sensitivity analyses in subgroups of patients who were fully abstinent during the second assessment yielded very similar results.

CONCLUSIONS

These findings strongly suggest that a pragmatic approach, in which patients are evaluated for ADHD even when they are not (yet) abstinent, is feasible and justifiable.

Methylphenidate doses in Attention Deficit/Hyperactivity Disorder and comorbid substance use disorders

Patients with Attention Deficit/Hyperactivity Disorder (ADHD) and comorbid Substance Use Disorders (SUD) are increasingly being treated with central stimulant medication despite limited evidence for its effectiveness. Lack of longitudinal follow-up studies of dosing and adverse effects has resulted in conflicting treatment guidelines. This study aims to explore whether individuals with ADHD and comorbid SUD are treated with higher stimulant doses than individuals with ADHD only, and whether doses increase over time as a sign of tolerance, a core symptom of addiction. Information on methylphenidate doses for 14 314 Swedish adults, including 4870 individuals with comorbid SUD was obtained through linkages of Swedish national registers between 2006 and 2009. Differences in doses between patients with and without SUD were estimated using logistic regression while a linear regression model calculated time trends in mean doses. Individuals with SUD were prescribed higher methylphenidate doses than those without (OR_day365; 2.12, 95% CI 1.81-2.47: OR_day730 2.65, 95% CI 2.13-3.30). Patients with SUD were, two years after initiating stimulant treatment, prescribed approximately 40% higher doses compared to individuals with ADHD only. The results may suggest a need for increased doses in this population to achieve optimal ADHD symptom control. A tendency towards increasing doses during the first years of treatment, more pronounced in individuals with comorbid SUD, may reflect a reluctance to prescribe adequate doses due to lack of clinical guidelines. Mean doses stabilized after about two years in both groups, which does not lend support to continuously increasing tolerance over time.

Psychopathology and traffic violations in subjects who have lost their driving license

BACKGROUND

The persistence of risky behaviors while driving and traffic accidents despite campaigns to increase awareness suggest that there may be underlying causes that maintain proneness to traffic violations. The aim of the current study was to assess: a) the prevalence of psychopathology in a sample of people who have lost their driving license due to former traffic violations and b) the discriminatory capacity of each psychopathological disorder to differentiate among people with high and low proneness to perform risky behaviors while driving.

METHODS

383 participants in a course to recover their driving license after its loss due to previous traffic violations were included. The International Neuropsychiatric Interview (M.I.N.I.) according to DSM-IV was used to assess psychopathology.

RESULTS

Between 67% and 76.2% of the participants had been affected by a lifetime psychopathological disorder until the moment of assessment. The most prevalent diagnoses were substance abuse including alcohol (52.5-62.7%), ADHD (19.7-28.5%), depression (7.9-14.4%) and anxiety (3.6-12.4%). Substance abuse and ADHD also showed the strongest set of associations with specific risk behaviors, but ADHD emerged as the most discriminant disorder to distinguish between those people at high and low risk of while driving.

CONCLUSIONS

The results of the current study suggest that addressing psychopathology explicitly to prevent risky behaviors and recidivism while driving would provide benefits in this area.

ADHD, Conduct Disorder, Substance Use Disorder, and Nonprescription Stimulant Use

OBJECTIVE

To assess whether the relationship of an ADHD diagnosis by adolescence to nonprescription stimulant use in adulthood is direct or indirect, via Conduct Disorder (CD) and/or Substance Use Disorder (SUD).

METHOD

Data were obtained from multiple waves of interviews and questionnaires completed by 551 community-based participants when they were between the mean ages of 14.1 and 36.6 years.

RESULTS

The results of the structural equation model (SEM) supported both a direct association between early ADHD and later nonprescription stimulant use ( B = .18, z = 2.74) and the relationship from ADHD to later nonprescription stimulant use ( B = .01, z = 1.72) via CD and SUD.

CONCLUSION

The longitudinal data supporting these paths suggest that efforts to prevent and treat the misuse of nonprescription stimulants may be more effective if attention is paid to those with a history of ADHD, as well as to those who also had CD and SUD.

Clinical and neurobiological factors in the management of treatment refractory attention-deficit hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a highly prevalent mental disorder of childhood, which often continues into adolescence and adulthood. Stimulants such as methylphenidate (MPH) and non-stimulants such as atomoxetine are effective medications for the treatment of ADHD. However, about 30% of patients do not respond to these medications. Pharmacological treatment for ADHD, although highly effective, is associated with marked variabilities in clinical response, optimal dosage needed and tolerability. This article provides an overview of up-to-date knowledge regarding the clinical and neurobiological factors which contribute to and help predict treatment-refractory ADHD. Pharmacogenetic, pharmacogenomics and neuroimaging studies are still controversial with respect to determining the associations between response to medication and genetic factors, thereby resulting in hypotheses that differences in the genetic factors and neuroimaging findings contribute to treatment outcome. Much research on the potential role of genotype in pharmacological effects has focused on the catecholaminergic gene related to executive functions. Many neuroimaging studies have also reported a relationship between treatment response and common patterns of brain structure or activity according to various genetic polymorphisms. When children, adolescents and adults with ADHD do not respond to MPH, we should consider additional pharmacological options, including other classes of psychostimulants, the nonstimulant atomoxetine, bupropion, tricyclic antidepressant, clonidine, guanfacine and lisdexamphetamine. Prudent choice of an appropriate medication and active engagement of children, parents, and teachers in daily management may help to ensure long-term adherence. Therefore, additional research might help to optimize the treatment of children, adolescents and adults with ADHD and to find new options for the treatment of patients who do not respond to stimulants and the other medications. Because these findings should be interpreted cautiously, further studies are needed to elucidate these issues more clearly.

The Prevalence of ADHD and Comorbid Disorders in Iranian Adult Male Prison Inmates

OBJECTIVE

The aim of the present study was to explore the prevalence of ADHD and comorbid disorders in a community sample of adult male prisoners in Iran.

METHOD

Through stratified sampling method, 908 adult male prison inmates in Gorgan Prison were recruited on a voluntary basis. Diagnostic assessments were based on the Adult ADHD Self-Report Scale Screener and a clinical interview based on Diagnostic and Statistical Manual of Mental Disorders (4th ed.) criteria and psychiatric interview. Comorbid disorders were assessed with the Beck Anxiety Inventory, Beck Depression Inventory-Second Edition, and Millon Clinical Multiaxial Inventory-III.

RESULTS

ADHD was present in 147 participants (16.2%). Eighty-five percent of participants with ADHD reported lifetime substance abuse. They had higher rates of mood (40.8%) and anxiety (55.1%) disorders. Antisocial and borderline personality disorders were also more prevalent among offenders with ADHD.

CONCLUSION

ADHD is prevalent in offenders and it is associated with comorbid disorders. The results emphasize the necessity of treatment programs for offenders with ADHD.

Factors Associated With Adherence to Methylphenidate Treatment in Adult Patients With Attention-Deficit/Hyperactivity Disorder and Substance Use Disorders

Adherence to treatment is one of the most consistent factors associated with a favorable addiction treatment outcome. Little is known about factors associated with treatment adherence in individuals affected with comorbid attention-deficit/hyperactivity disorder and substance use disorders (SUD). This study aimed to explore whether treatment-associated factors, such as the prescribing physician's (sub)specialty and methylphenidate (MPH) dose, or patient-related factors, such as sex, age, SUD subtype, and psychiatric comorbidity, were associated with adherence to MPH treatment. Swedish national registers were used to identify adult individuals with prescriptions of MPH and medications specifically used in the treatment of SUD or a diagnosis of SUD and/or coexisting psychiatric diagnoses. Primary outcome measure was days in active MPH treatment in stratified dose groups (≤36 mg, ≥37 mg to ≤54 mg, ≥55 mg to ≤72 mg, ≥73 mg to ≤90 mg, ≥91 mg to ≤108 mg, and ≥109 mg). Lower MPH doses (ie, ≤36 mg day 100) were associated with treatment discontinuation between days 101 and 830 (HR≤36 mg, 1.67; HR37-54mg, 1.37; HR55-72mg, 1.36; HR73-90mg, 1.19; HR≥108mg, 1.09). The results showed a linear trend (P < 0.0001) toward decreased risk of treatment discontinuation along with increase of MPH doses. In conclusion, this study shows that higher MPH doses were associated with long-term treatment adherence in individuals with attention-deficit/hyperactivity disorder and SUD.

Adult ADHD: A new disease?

OBJECTIVES

Until recently, it was believed that attention deficit and hyperactivity disorder (ADHD) are outgrown by the end of adolescence and the beginning of adulthood. The purpose of this review is to describe the characteristics of the disease in adults, depict comorbidities that accompany it, and expand the scope over methods of diagnosis and treatment of these ages.

METHODS

A search was conducted in the PubMed/MEDLINE database for relevant key words 'ADHD', 'attention deficit', 'hyperactivity' and 'adult'. Secondary search parameters were 'comorbid', 'prevalence', 'epidemiology', 'therapy' and 'drug therapy'. Search was limited to 'English' and 'Humans'.

RESULTS

Over the years, the persistent nature of the disorder has been clarified, elucidating prevalence rate, gender differences and subtype shifts among adult ADHD population. Nevertheless, even today, there is only limited awareness of the existence of the disorder across one's lifespan, its consequences and the appropriate treatment.

CONCLUSIONS

Our results emphasise the growing awareness of adult psychosocial impairments due to ADHD symptoms and comorbidities, as well as the need for further collaboration among practitioners and mental health-care professionals to better identify the condition and allow for effective treatment.

Expert Opinion and Recommendations for the Management of Attention-Deficit/Hyperactivity Disorder in Correctional Facilities

There has been considerably less research on the management of adult attention-deficit/hyperactivity disorder (ADHD) among the inmates of correctional facilities than in the general community. While the successful identification and management of ADHD in the adult correctional setting offer potential benefits to the individuals themselves, to institutional staff, and to wider society, their implementation represents significant challenges. These include high prevalence rates, the low level of ADHD recognition, the high incidence of comorbid psychiatric disorders, and the high risk of abuse and diversion of prescribed medications. Here, the authors provide an overview of current recommendations for the identification and management of adults with ADHD in correctional settings and discuss possible strategies for their further development.

An application of analyzing the trajectories of two disorders: A parallel piecewise growth model of substance use and attention-deficit/hyperactivity disorder

Researchers often want to examine 2 comorbid conditions simultaneously. One strategy to do so is through the use of parallel latent growth curve modeling (LGCM). This statistical technique allows for the simultaneous evaluation of 2 disorders to determine the explanations and predictors of change over time. Additionally, a piecewise model can help identify whether there are more than 2 growth processes within each disorder (e.g., during a clinical trial). A parallel piecewise LGCM was applied to self-reported attention-deficit/hyperactivity disorder (ADHD) and self-reported substance use symptoms in 303 adolescents enrolled in cognitive-behavioral therapy treatment for a substance use disorder and receiving either oral-methylphenidate or placebo for ADHD across 16 weeks. Assessing these 2 disorders concurrently allowed us to determine whether elevated levels of 1 disorder predicted elevated levels or increased risk of the other disorder. First, a piecewise growth model measured ADHD and substance use separately. Next, a parallel piecewise LGCM was used to estimate the regressions across disorders to determine whether higher scores at baseline of the disorders (i.e., ADHD or substance use disorder) predicted rates of change in the related disorder. Finally, treatment was added to the model to predict change. While the analyses revealed no significant relationships across disorders, this study explains and applies a parallel piecewise growth model to examine the developmental processes of comorbid conditions over the course of a clinical trial. Strengths of piecewise and parallel LGCMs for other addictions researchers interested in examining dual processes over time are discussed.

Criteria and Concurrent Validity of Adult ADHD Section of the Psychiatry Research Interview for Substance and Mental Disorders

OBJECTIVE

Prevalence of ADHD in adults is around 2% to 4%. Comorbidity is frequent in ADHD; 75% of patients develop a comorbid disorder across life span, substance use disorder (SUD) being one of the most prevalent.

METHOD

A case-control study was performed to check the criteria and concurrent validity of psychiatric research interview for substance and mental disorders (PRISM) adult ADHD section. Validation was done comparing PRISM with the Conners' Adult ADHD Diagnostic Interview for Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.). A convenient sample (N = 80) participated, 40 had diagnosis of SUD and ADHD and 40 had diagnosis of SUD without ADHD. The statistics hypothesis was bivariant, and the confidence level was 95%.

RESULTS

Kappa index concordance was .78, sensitivity of PRISM adult ADHD module was 90%, specificity was 87.5%, positive predictive value was 87.8%, and the negative predictive value was 89.7%.

CONCLUSION

PRISM has good psychometric properties to detect ADHD associated with SUD.

Impaired reward processing in the human prefrontal cortex distinguishes between persistent and remittent attention deficit hyperactivity disorder

Symptoms of attention deficit hyperactivity disorder (ADHD) in children often persist into adulthood and can lead to severe antisocial behavior. However, to-date it remains unclear whether neuro-functional abnormalities cause ADHD, which in turn can then provide a marker of persistent ADHD. Using event-related functional magnetic resonance imaging (fMRI), we measured blood oxygenation level dependent (BOLD) signal changes in subjects during a reversal learning task in which choice of the correct stimulus led to a probabilistically determined 'monetary' reward or punishment. Participants were diagnosed with ADHD during their childhood (N=32) and were paired with age, gender, and education matched healthy controls (N=32). Reassessment of the ADHD group as adults resulted in a split between either persistent (persisters, N=17) or remitted ADHDs (remitters, N=15). All three groups showed significantly decreased activation in the medial prefrontal cortex (PFC) and the left striatum during punished correct responses, however only remitters and controls presented significant psycho-physiological interaction between these fronto-striatal reward and outcome valence networks. Comparing persisters to remitters and controls showed significantly inverted responses to punishment (P<0.05, family-wise error corrected) in left PFC region. Interestingly, the decreased activation shown after punishment was located in different areas of the PFC for remitters compared with controls, suggesting that remitters might have learned compensation strategies to overcome their ADHD symptoms. Thus, fMRI helps understanding the neuro-functional basis of ADHD related behavior differences and differentiates between persistent and remittent ADHD.

Integrated cognitive behavioral therapy for patients with substance use disorder and comorbid ADHD: two case presentations

Two cases of integrated cognitive behavioral therapy (ICBT) for substance use disorder (SUD) and Attention Deficit Hyperactivity Disorder (ADHD) are presented illustrating that ICBT is a promising new treatment option.

Comorbid attention deficit hyperactivity disorder and substance use disorder complexity and chronicity in treatment-seeking adults

INTRODUCTION AND AIMS

Attention deficit hyperactivity disorder (ADHD) is a known risk factor for substance use disorder (SUD); however, the potential additive contribution of comorbid ADHD to drug-specific dependence in SUD populations is largely unknown. The current study aimed to assess this association between ADHD symptoms and drug-specific SUD complexity and chronicity.

DESIGN AND METHODS

A cross-sectional survey was administered to a convenience sample of 489 adults receiving SUD treatment at 16 Australian drug and alcohol treatment centres between September 2010 and August 2011. Participants were screened for adult ADHD symptoms using the Adult ADHD Self-Report Scale. Associations between ADHD screening status and drug-specific SUD complexity and chronicity were assessed using multivariate logistic and modified Poisson regression analysis, controlling for a range of potential confounders.

RESULTS

Overall, 215 (44%) patients screened positive for concurrent adult ADHD and SUD. After Simes' correction, a significant positive association was observed between ADHD screening status and current amphetamine SUD (odds ratio (OR) = 1.85; 95% confidence interval (CI): 1.19-2.36). Patients who screened positive for ADHD were significantly more likely to report SUD history for heavy alcohol use (OR = 2.05; 95% CI: 1.21-3.45) and amphetamine (OR = 1.96; 95% CI: 1.26-3.06) as well as significantly increased risk of moderate (3-4 years) duration for benzodiazepine and amphetamine SUDs and long (≥5 years) duration for alcohol, opiates other than heroin or methadone, and amphetamine SUDs.

DISCUSSION AND CONCLUSIONS

The findings provide evidence that there is increased drug dependence complexity and chronicity in treatment-seeking SUD patients who screen positively for ADHD, specifically for amphetamine, alcohol, opiates other than heroin or methadone, and benzodiazepines.

Internet addiction is related to attention deficit but not hyperactivity in a sample of high school students

OBJECTIVE

To assess the effects of attention-deficit/hyperactivity disorder (ADHD) symptom dimensions on Internet addiction (IA) after controlling for Internet usage features among high school students.

METHODS

This study consisted of 640 students (331 females and 309 males) ranging from 14 to 19 years of age. The Internet Addiction Scale, the Conners-Wells' Adolescent Self-Report Scale-Short Form, and a personal information form were completed by the participants. Statistical analyses were conducted for both sexes and the total sample.

RESULTS

According to the logistic regression analysis, attention deficit and playing online games were significant predictors of IA in both sexes. Other predictors of IA included behavioral problems for females, total weekly Internet usage time, and lifelong total Internet use for males. Hyperactivity and other Internet usage features did not predict IA.

CONCLUSION

These results suggest that attention deficit and playing online games are important determinants of IA in this age group.

The Ethics of Neuroenhancement

According to several recent studies, a big chunk of college students in North America and Europe uses so called ‘smart drugs' to enhance their cognitive capacities aiming at improving their academic performance. With these practices, there comes a certain moral unease. This unease is shared by many, yet it is difficult to pinpoint and in need of justification. Other than simply pointing to the medical risks coming along with using non-prescribed medication, the salient moral question is whether these practices are troubling in and of themselves. In due consideration of empirical insights into the concrete effects of smart drugs on brain and behavior, our attempt is to articulate wherein this moral unease consists and to argue for why the authors believe cognitive enhancement to be morally objectionable. The authors will contend that the moral problem with these practices lies less in the end it seeks, than in the underlying human disposition it expresses and promotes. Some might ask, what is wrong with molding our cognitive capacities to achieve excellence, get a competitive edge, or, as the whim takes us? In all of these occasions, the usage of smart drugs serves a certain goal, a telos. The goal is, broadly speaking, this: outsmarting opponents in an arms race for limited resources and thereby yielding a competitive edge. In plain words: competition is valued higher than cooperation or solidarity. What is wrong with striving for this goal? The authors submit that the question whether people really want to live in a society that promotes the mentality ‘individual competition over societal cooperation' deserves serious consideration. In developing their answer, the authors draw on an ‘Ethics of Constraint' framework, arguing that widespread off-label use of smart drugs bears the risk of negative neural/behavioral consequences for the individual that might, in the long run, be accompanied by changing social value orientations for the worse.

Applications of the Neonatal Quinpirole Model to Psychosis and Convergence upon the Dopamine D2 Receptor

This mini review focuses on the importance of the dopamine D₂-like receptor family and its importance in psychosis. Past findings from this laboratory along with collaborators have been that neonatal quinpirole (a dopamine D₂-like receptor agonist) results in increases in dopamine D₂ receptor sensitivity that persists throughout the animal's lifetime. Findings from this model have been shown to have particular application and validity to schizophrenia, but may have broader implications toward other psychoses, which is reviewed in the present manuscript. In the present review, we also highlight other models of psychoses that have been centered on the subchronic administration of quinpirole to rats in order to model certain psychoses, which has uncovered some interesting and valid behavioral findings. This review highlights the importance of the combination of behavioral findings and neurobiological mechanisms focusing on neural plasticity in discovering underlying pathologies in these disorders that may lead to treatment discoveries, as well as the value of animal models across all psychoses.

ADHD and the externalizing spectrum: direct comparison of categorical, continuous, and hybrid models of liability in a nationally representative sample

PURPOSE

Alcohol use disorders, substance use disorders, and antisocial personality disorder share a common externalizing liability, which may also include attention-deficit hyperactivity disorder (ADHD). However, few studies have compared formal quantitative models of externalizing liability, with the aim of delineating the categorical and/or continuous nature of this liability in the community. This study compares categorical, continuous, and hybrid models of externalizing liability.

METHOD

Data were derived from the 2004-2005 National Epidemiologic Survey on Alcohol and Related Conditions (N = 34,653). Seven disorders were modeled: childhood ADHD and lifetime diagnoses of antisocial personality disorder (ASPD), nicotine dependence, alcohol dependence, marijuana dependence, cocaine dependence, and other substance dependence.

RESULTS

The continuous latent trait model provided the best fit to the data. Measurement invariance analyses supported the fit of the model across genders, with females displaying a significantly lower probability of experiencing externalizing disorders. Cocaine dependence, marijuana dependence, other substance dependence, alcohol dependence, ASPD, nicotine dependence, and ADHD provided the greatest information, respectively, about the underlying externalizing continuum.

CONCLUSIONS

Liability to externalizing disorders is continuous and dimensional in severity. The findings have important implications for the organizational structure of externalizing psychopathology in psychiatric nomenclatures.

The complicated relationship between attention deficit/hyperactivity disorder and substance use disorders

Adolescents and young adults with substance use disorders (SUD) and attention deficit/hyperactivity disorder (ADHD) are increasingly presenting in clinical practice. The overlap and role of treatment for these co-occurring disorders remains unclear. A review of the literature was conducted to highlight and update recent evidence on the overlap of ADHD and SUD, the role of ADHD medication on later SUD, and the treatment of ADHD and SUD in adolescents and young adults. Recent work continues to highlight the high risk for comorbid ADHD in patients with SUD; and conversely, the high risk for SUD developing in ADHD across the lifespan, particularly in the context of comorbid conduct disorder. Although the data remains discordant, it appears that ADHD pharmacotherapy does not increase the risk for SUD. Medication treatment alone does not appear to be particularly effective in treating SUD in currently active substance abusing individuals with ADHD. Structured therapies may be effective in treating adolescents and young adults with ADHD and SUD. Further controlled trials evaluating the sequence and effect of structured psychotherapies and/or ADHD pharmacotherapy on SUD relapse in these groups are warranted.

Identifying a consistent pattern of neural function in attention deficit hyperactivity disorder: a meta-analysis

BACKGROUND

The neurobiological underpinnings of attention deficit hyperactivity disorder (ADHD) are inconclusive. Activation abnormalities across brain regions in ADHD compared with healthy controls highlighted in task-based functional magnetic resonance imaging (fMRI) studies are heterogeneous. To identify a consistent pattern of neural dysfunction in ADHD, a meta-analysis of fMRI studies using Go/no-go, Stop and N-back tasks was undertaken.

METHOD

Several databases were searched using the key words: 'ADHD and fMRI' and 'ADHD and fMRI task'. In all, 20 studies met inclusion criteria comprising 334 patients with ADHD and 372 healthy controls and were split into N-back, Stop task and Go/no-go case-control groups. Using Signed Differential Mapping each batch was meta-analysed individually and meta-regression analyses were used to examine the effects of exposure to methylphenidate (MPH), length of MPH wash-out period, ADHD subtype, age and intelligence quotient (IQ) differences upon neural dysfunction in ADHD.

RESULTS

Across all tasks less activity in frontal lobe regions compared with controls was detected. Less exposure to treatment and lengthier wash-out times resulted in less left medial frontal cortex activation in N-back and Go/no-go studies. Higher percentage of combined-type ADHD resulted in less superior and inferior frontal gyrus activation. Different IQ scores between groups were linked to reduced right caudate activity in ADHD.

CONCLUSIONS

Consistent frontal deficits imply homogeneous cognitive strategies involved in ADHD behavioural control. Our findings suggest a link between fMRI results and the potentially normalizing effect of treatment and signify a need for segregated examination and contrast of differences in sample characteristics in future studies.

A Review of the Pathophysiology, Etiology, and Treatment of Attention-Deficit Hyperactivity Disorder (ADHD)

Objective: To review the pathophysiology, etiology, and treatment of attention-deficit hyperactivity disorder (ADHD). Data Sources and Data Extraction: A literature search was conducted in PubMed and EMBASE using the terms attention deficit hyperactive disorder, ADHD, pathophysiology, etiology, and neurobiology. Limits applied were the following: published in the past 10 years (January 2003 to August 2013), humans, review, meta-analysis, and English language. These yielded 63 articles in PubMed and 74 in EMBASE. After removing duplicate/irrelevant articles, 86 articles and their relevant reference citations were reviewed. Data Synthesis: ADHD is a neurological disorder that affects children, but symptoms may persist into adulthood. Individuals suffering from this disorder exhibit hyperactivity, inattention, impulsivity, and problems in social interaction and academic performance. Medications used to treat ADHD such as methylphenidate, amphetamine, and atomoxetine indicate a dopamine/norepinephrine deficit as the neurochemical basis of ADHD, but the etiology is more complex. Moreover, these agents have poor adverse effect profiles and a multitude of drug interactions. Because these drugs are also dispensed to adults who may have concomitant conditions or medications, a pharmacist needs to be aware of these adverse events and drug interactions. This review, therefore, focuses on the pathophysiology, etiology, and treatment of ADHD and details the adverse effects and drug interaction profiles of the drugs used to treat it. Conclusions: Published research shows the benefit of drug therapy for ADHD in children, but given the poor adverse effect and drug interaction profiles, these must be dispensed with caution.

Neuroimaging markers for the prediction of treatment response to Methylphenidate in ADHD

BACKGROUND

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most prevalent mental disorders of childhood, which often continues into adulthood. Methylphenidate is one the most commonly used medication to treat ADHD, however up to 30% of patients do not respond to it.

AIMS

This paper aims to review studies, which employed neuroimaging to predict treatment response to Methylphenidate in ADHD.

METHODS

Systematic literature searches were performed using several databases. Selected articles had to describe an original study that identified neuroimaging markers for the prediction of treatment response to Methylphenidate in ADHD.

RESULTS

Eighty-three articles were found, of which twelve were selected for the present review. Several neuroimaging markers to predict response to MPH were suggested including DAT status, size of medial prefrontal cortex and corpus callosum.

CONCLUSION

Some promising findings have been identified and they should motivate additional work to establish more reliable neuroimaging markers of treatment response to MPH in ADHD.

Behavioral endophenotypes of drug addiction: Etiological insights from neuroimaging studies

This article reviews recent advances in the elucidation of neurobehavioral endophenotypes associated with drug addiction made possible by the translational neuroimaging techniques magnetic resonance imaging (MRI) and positron emission tomography (PET). Increasingly, these non-invasive imaging approaches have been the catalyst for advancing our understanding of the etiology of drug addiction as a brain disorder involving complex interactions between pre-disposing behavioral traits, environmental influences and neural perturbations arising from the chronic abuse of licit and illicit drugs. In this article we discuss the causal role of trait markers associated with impulsivity and novelty-/sensation-seeking in speeding the development of compulsive drug administration and in facilitating relapse. We also discuss the striking convergence of imaging findings from these behavioural traits and addiction in rats, monkeys and humans with a focus on biomarkers of dopamine neurotransmission, and highlight areas where further research is needed to disambiguate underlying causal mechanisms. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.

The brain activations for both cue-induced gaming urge and smoking craving among subjects comorbid with Internet gaming addiction and nicotine dependence

Internet gaming addiction (IGA) has been classified as an addictive disorder in the proposed DSM 5 draft. However, whether its underlying addiction mechanism is similar to other substance use disorders has not been confirmed. The present functional magnetic resonance images study is aimed at evaluating the brain correlates of cue-induced gaming urge or smoking craving in subjects with both IGA and nicotine dependence to make a simultaneous comparison of cue induced brain reactivity for gaming and smoking. For this purpose, 16 subjects with both IGA and nicotine dependence (comorbid group) and 16 controls were recruited from the community. All subjects were made to undergo 3-T fMRIs scans while viewing images associated with online games, smoking, and neutral images, which were arranged according to an event-related design. The resultant image data was analyzed with full factorial and conjunction analysis of SPM5. The results demonstrate that anterior cingulate, and parahippocampus activates higher for both cue-induced gaming urge and smoking craving among the comorbid group in comparison to the control group. The conjunction analysis demonstrates that bilateral parahippocampal gyrus activates to a greater degree for both gaming urge and smoking craving among the comorbid group in comparison to the control group. Accordingly, the study demonstrates that both IGA and nicotine dependence share similar mechanisms of cue-induced reactivity over the fronto-limbic network, particularly for the parahippocampus. The results support that the context representation provided by the parahippocampus is a key mechanism for not only cue-induced smoking craving, but also for cue-induced gaming urge.

Practitioner review: current best practice in the management of adverse events during treatment with ADHD medications in children and adolescents

BACKGROUND

Medication is an important element of therapeutic strategies for ADHD. While medications for ADHD are generally well-tolerated, there are common, although less severe, as well as rare but severe adverse events AEs during treatment with ADHD drugs. The aim of this review is to provide evidence- and expert-based guidance concerning the management of (AEs) with medications for ADHD.

METHODS

For ease of use by practitioners and clinicians, the article is organized in a simple question and answer format regarding the prevalence and management of the most common AEs. Answers were based on empirical evidence from studies (preferably meta-analyses or systematic reviews) retrieved in PubMed, Ovid, EMBASE and Web of Knowledge through 30 June 2012. When no empirical evidence was available, expert consensus of the members of the European ADHD Guidelines Group is provided. The evidence-level of the management recommendations was based on the SIGN grading system.

RESULTS

The review covers monitoring and management strategies of loss of appetite and growth delay, cardiovascular risks, sleep disturbance, tics, substance misuse/abuse, seizures, suicidal thoughts/behaviours and psychotic symptoms.

CONCLUSION

Most AEs during treatment with drugs for ADHD are manageable and most of the times it is not necessary to stop medication, so that patients with ADHD may continue to benefit from the effectiveness of pharmacological treatment.