Clinical and genetic characteristics of Korean male alcoholics with and without attention deficit hyperactivity disorder

Detecting the comorbidity of attention deficit hyperactivity disorder (ADHD) in a population of outpatients with alcohol use disorder (AUD): The role of personality traits, age at first alcohol use and level of craving

Attention-deficit/hyperactivity disorder (ADHD) commonly affects individuals with alcohol use disorder (AUD). However, despite the negative outcomes associated with this comorbidity, ADHD is underdiagnosed in this population. We aim to identify clinical parameters and propose cutoff scores enabling the detection of ADHD among patients with AUD. We retrospectively analyzed data from 199 patients, out of a global sample of 412 who were consecutively admitted to a day hospital for alcohol-related problems between 2009 and 2022. We found that lower level of self-directedness, higher levels of novelty seeking, self-transcendence, harm avoidance and craving, and earlier first alcohol consumption could accurately predict the presence of ADHD in AUD (AUC = 0.926). Self-directedness and novelty seeking had the best predictive abilities: a self-directedness score below 52 was associated with an accuracy of 82% and, combined with a novelty seeking score over 53, the accuracy reached 85%. Such findings could be useful to help clinicians detect ADHD in patients with AUD so that they can receive the adequate care.

Attention-deficit hyperactivity symptoms and risk of alcohol use relapse

AIM

Alcohol use disorder (AUD) is frequently accompanied by comorbid attention-deficit hyperactivity disorder (ADHD). Comorbid ADHD has been reported to increase the severity of AUD. We investigated whether ADHD severity also influences AUD relapse risk at baseline and after inpatient treatment.

METHODS

In this study, 187 AUD patients admitted to Narimasu Kosei Hospital from October 2019 to March 2021 were included in the analysis. According to the Adult ADHD Self-Report Scale (ASRS), participants were divided into two groups: ASRS+ with ADHD characteristics (n = 43) and ASRS- with low/no ADHD characteristics (n = 144). Groups were compared for AUD relapse risk at the start of treatment (baseline) and before hospital discharge using the multidimensional Alcohol Relapse Risk Scale (ARRS). The change in relapse risk during hospitalization was also compared by assessment of the interaction between groups (ASRS+ vs. ASRS-) and time (at discharge vs. baseline).

RESULTS

The total ARRS score and dimension subscores for stimulus-induced vulnerability and emotionality problems were significantly higher in the ASRS+ group at baseline and before discharge compared to the ASRS- group. There was a significant group × time interaction indicating less improvement of stimulus-induced vulnerability during inpatient treatment among the ASRS+ group compared to the ASRS- group.

CONCLUSIONS

Our findings suggest that AUD patients with ADHD characteristics have a higher risk of relapse both at baseline and after inpatient treatment. Stimulus-induced vulnerability to relapse is less likely to improve with treatment in patients with ADHD characteristics.

Risk behaviors in substance use disorder in a sample of Egyptian female patients with or without symptoms of attention-deficit hyperactivity disorder

Background

Risk-taking behaviors are associated with attention-deficit hyperactivity disorder (ADHD) and substance use disorder (SUD). Individuals with both diagnoses have been reported to have an earlier onset, a longer course, and greater severity, with more relapses and greater difficulty remaining abstinent.

The current study was assessing females seeking treatment for SUDs for the presence of comorbid ADHD, to investigate the association between severity of SUD and co-occurring ADHD symptoms and to examine related risk behaviors. Therefore, thirty female patients were enrolled, and demographic data was collected. Participants were interviewed by SCID I, addiction severity index, Arabic-translated and validated version of the adult ADHD Self-Report Scale Barratt Impulsiveness Scale Version 11, and Arabic version of the Adult Scale of Hostility and Aggression.

Results

Thirty female patients were included in the study, and 33.3% had extreme severity, on the addiction severity index scale. Fifteen patients had ADHD symptoms; 33.3% had high likely scores, according to Adult ADHD Self-Reported Scale (ASRS). There is a significant difference regarding the age of onset of substance use and smoking (P = 0.029), first sexual activity (P = 0.002), number of sexual partners (P = 0.009), impairment in employment, and family and social relationships items (P = 0.024, P = 0.028, respectively) in SUD patients with ADHD symptoms than in SUD patients without ADHD symptoms.

Conclusion

Female patients diagnosed with adult ADHD have an earlier age of smoking and substance use, having first sexual activity at younger age, and having more sexual partners with more employment, family, and social relationship problems.

Developmental trajectory classes in psychological dysregulation predict later decision-making competence

Adolescence and emerging adulthood are developmental periods associated with increased risk taking, including alcohol and substance use and antisocial behaviors. Typical psychological growth from adolescence into early adulthood reflects increases in traits related to psychological regulation (e.g., greater emotional stability and less impulsivity), which are typically considered protective factors against risk behaviors. However, individuals may vary greatly in their development of these characteristics. This study examines the degree to which heterogeneity in developmental trajectories of psychological regulation are associated with later performance on decision-making skills battery. In this study, psychological regulation was assessed at age 10-12, with follow-up assessments at 14, 16, and 19 years. At age 19, we administered the Youth Decision-Making Competence (DMC; Parker & Fischhoff, 2005) measure. Correlational analyses revealed that lower psychological regulation, as early as age 10, was associated with lower DMC scores. A latent class growth mixture model yielded three distinct developmental trajectory classes of psychological dysregulation: (a) a Moderate-Stable group, a modal class that demonstrated stable and average regulative tendencies throughout adolescence, (b) a Low-Decreasing group, which demonstrated greater self-regulation throughout childhood, and a (c) High-Increasing group, which demonstrated low self-regulative tendencies (higher dysregulation) at age 10 that became increasingly dysregulated throughout adolescence. Individuals in the High-Increasing group demonstrated lower DMC performance than those in the Moderate-Stable and Low-Decreasing groups. Our findings also reinforce past work that indicates considerable individual differences in intra-individual change across adolescence, and that early patterns of psychological dysregulation development can impact later decision-making tendencies.

Impact of Sex and ADHD Status on Psychiatric Comorbidity in Treatment-Seeking Alcoholics

Objective: To assess for intrasex and intersex differences in psychiatric comorbidity according to ADHD status in treatment-seeking adults with alcohol use disorders (AUDs). Method: This study was a secondary analysis of data utilizing descriptive statistics from 472 treatment-seeking alcoholics who completed the Psychiatric Research Interview for Substance and Mental Disorders (PRISM). Results: The prevalence of ADHD in males and females was 6.0% and 6.4%, respectively. Males with ADHD and AUDs had higher rates of current and lifetime drug use disorders, current depressive disorders, and current and lifetime anxiety disorders than male alcoholics without ADHD. No intrasex differences in psychiatric comorbidities were identified in female alcoholics with respect to ADHD status. Males with ADHD and AUDs were more likely to have had opioid dependence than ADHD-positive females. No other intersex differences were found. Conclusion: Positive ADHD status was associated with increased psychiatric comorbidity among treatment-seeking alcoholic men.

Quality of life in substance use disorder patients with and without attention deficit hyperactivity disorder 12 months after treatment: a naturalistic follow-up study

There is sparse research on quality of life (QoL) as an outcome measure in patients with substance use disorders (SUD), with or without attention deficit hyperactivity disorder (ADHD). We aimed to investigate whether SUD patients with and without ADHD (SUD + ADHD vs. SUD - ADHD) differed in QoL at baseline and at a 12-month follow-up after SUD treatment. The groups were additionally compared with data from a national population sample (NPS). From a sample of 16 SUD + ADHD and 87 SUD - ADHD patients originally recruited between 2010 and 2012, eight SUD + ADHD (50.0%) and 28 SUD - ADHD (32.2%) patients were reached at follow-up. QoL was measured with the short version of the World Health Organization QoL instrument (WHOQOL-BREF). Cross-sectional data on QoL from NPS was utilized. Compared to NPS, SUD patients reported significantly lower QoL at baseline and follow-up. Furthermore, QoL was similar at baseline in SUD + ADHD and SUD - ADHD patients. At a 12-month follow-up after SUD treatment, SUD + ADHD patients 'QoL had improved, however, not significantly differing from SUD - ADHD patients or the NPS. SUD - ADHD patients' QoL remained significantly lower. At follow-up, SUD + ADHD patients' QoL improved nominally compared to SUD - ADHD patients, but not the NPS. The clinical and functional relevance of these findings should be investigated further.

Serial Progression from Attention-Deficit/Hyperactivity Disorder to Alcohol Use Disorder: Serial Multiple Mediated Effects of Externalizing Disorders and Depression

Objective

Externalizing disorders such as attention-deficit/hyperactivity disorder (ADHD), conduct disorder and antisocial personality disorder, as well as depression are common comorbidities in alcohol use disorder (AUD). The current study focused on the temporal relationship between the onsets of these disorders and AUD, and investigated the serial multiple mediator model of externalizing disorders (e.g., ADHD) and depression on AUD.

Methods

We analyzed the mediated effects of the Adult ADHD Self-Report Scale (ASRS), the Barratt Impulsiveness Scale motor (BIS_M) and the Beck Depression Inventory (BDI) on Korean version of the Alcohol Dependence Scale (ADS_K) using the multiple-step multiple mediation procedure regression analysis. In addition, we comparatively analyzed different clinical characteristics in relation to conduct problems.

Results

The multiple-step multiple mediation procedure found the serial multiple mediated effects of the BIS_M and the BDI on the relationship between the ASRS and the ADS_K. Also, the group with conduct problem was significantly high in ADHD symptoms, depression, anxiety, impulsivity, legal problems and alcohol-related problems, compared to the group without conduct problems.

Conclusion

To sum up, the results of this study show that ADHD symptoms in childhood could exert significant effects on the severity of AUD in adulthood, and both disorders might be mediated by the externalizing disorders characterized by the core feature of motor impulsivity, and depression serially. Thus, the treatment of preceding disorders in accordance with developmental stages is an overarching clinical component for preventing the subsequent development of AUD and for its treatment.

Open-label, dose-titration tolerability study of atomoxetine hydrochloride in Korean, Chinese, and Taiwanese adults with attention-deficit/hyperactivity disorder

INTRODUCTION

The primary objective of this study was to assess the overall safety and tolerability of atomoxetine in Korean, Chinese, and Taiwanese adults with attention-deficit/hyperactivity disorder (ADHD).

METHODS

A total of 44 patients aged ≥18 years who met the Conners' Adult ADHD Diagnostic Interview for DSM-IV diagnostic criteria for ADHD were enrolled from China, Korea, and Taiwan. In this open-label, dose-escalation study, patients received atomoxetine orally once daily over a period of eight weeks, starting at 40 mg/day (one week) up to a maximum dosage of 120 mg/day. Tolerability was evaluated by rate of discontinuation due to adverse events. Safety was assessed by recording all adverse events, laboratory tests, vital signs, and electrocardiograms. ADHD symptoms were evaluated by the Conners' Adult ADHD Rating Scale-Investigator Rated: Screening Version (CAARS-Inv:SV) for efficacy assessment.

RESULTS

Thirty-four patients (77.3%) completed the study. Atomoxetine was well tolerated with a discontinuation rate of 2.3% (1/44) due to adverse events. The most commonly reported adverse events were nausea, dizziness, and somnolence. The mean change from baseline to endpoint in CAARS-Inv:SV total ADHD symptom score was -12.5 (P < 0.001). A significant reduction in the CAARS-Inv:SV subscales (inattentive, hyperactive/impulsive, and ADHD index score, P < 0.001) was observed.

DISCUSSION

This is the first atomoxetine clinical trial in adult patients with ADHD in China, Korea, and Taiwan. Atomoxetine was well tolerated in doses of up to 120 mg/day with no unknown safety concerns.

Psychiatric comorbidity in treatment-seeking substance use disorder patients with and without attention deficit hyperactivity disorder: results of the IASP study

AIMS

To determine comorbidity patterns in treatment-seeking substance use disorder (SUD) patients with and without adult attention deficit hyperactivity disorder (ADHD), with an emphasis on subgroups defined by ADHD subtype, taking into account differences related to gender and primary substance of abuse.

DESIGN

Data were obtained from the cross-sectional International ADHD in Substance use disorder Prevalence (IASP) study.

SETTING

Forty-seven centres of SUD treatment in 10 countries.

PARTICIPANTS

A total of 1205 treatment-seeking SUD patients.

MEASUREMENTS

Structured diagnostic assessments were used for all disorders: presence of ADHD was assessed with the Conners' Adult ADHD Diagnostic Interview for DSM-IV (CAADID), the presence of antisocial personality disorder (ASPD), major depression (MD) and (hypo)manic episode (HME) was assessed with the Mini International Neuropsychiatric Interview-Plus (MINI Plus), and the presence of borderline personality disorder (BPD) was assessed with the Structured Clinical Interview for DSM-IV Axis II (SCID II).

FINDINGS

The prevalence of DSM-IV adult ADHD in this SUD sample was 13.9%. ASPD [odds ratio (OR) = 2.8, 95% confidence interval (CI) = 1.8-4.2], BPD (OR = 7.0, 95% CI = 3.1-15.6 for alcohol; OR = 3.4, 95% CI = 1.8-6.4 for drugs), MD in patients with alcohol as primary substance of abuse (OR = 4.1, 95% CI = 2.1-7.8) and HME (OR = 4.3, 95% CI = 2.1-8.7) were all more prevalent in ADHD(+) compared with ADHD(-) patients (P < 0.001). These results also indicate increased levels of BPD and MD for alcohol compared with drugs as primary substance of abuse. Comorbidity patterns differed between ADHD subtypes with increased MD in the inattentive and combined subtype (P < 0.01), increased HME and ASPD in the hyperactive/impulsive (P < 0.01) and combined subtypes (P < 0.001) and increased BPD in all subtypes (P < 0.001) compared with SUD patients without ADHD. Seventy-five per cent of ADHD patients had at least one additional comorbid disorder compared with 37% of SUD patients without ADHD.

CONCLUSIONS

Treatment-seeking substance use disorder patients with attention deficit hyperactivity disorder are at a very high risk for additional externalizing disorders.

Association study on pathological gambling and polymorphisms of dopamine D1, D2, D3, and D4 receptor genes in a Korean population

Several studies have reported that some dopaminergic receptor polymorphisms are associated with pathological gambling (PG). Considering that there are major race and ethnic group difference in dopaminergic polymorphisms, the result of genetic association studies should be confirmed in more homogeneous population to avoid problems of population stratification. The present study aimed to investigate whether selected polymorphisms in the dopamine receptors genes (DRD1, DRD2, DRD3, and DRD4) are associated with PG in Korean population which is consisted of only Korean ancestry. Subjects were 104 men with a diagnosis of PG and 114 unrelated age-matched normal control men. Genotyping was performed for the DRD1 gene -48 A/G, DRD2 gene TaqI A, DRD3 gene Ser9Gly, and DRD4 gene exon III variable number tandem repeat polymorphisms. The method of multifactor dimensionality reduction (MDR) was used to analyze gene-gene interactions. There were no differences in the frequencies of any studied polymorphisms between patients with PG and normal controls. MDR analysis did not show a significant effect of the 4 dopamine receptor gene polymorphisms on susceptibility to PG (P > 0.05). The present study suggests that the analyzed polymorphisms of the dopamine receptor genes might not be associated with PG in a Korean population.

The genetics of attention deficit/hyperactivity disorder in adults, a review

The adult form of attention deficit/hyperactivity disorder (aADHD) has a prevalence of up to 5% and is the most severe long-term outcome of this common neurodevelopmental disorder. Family studies in clinical samples suggest an increased familial liability for aADHD compared with childhood ADHD (cADHD), whereas twin studies based on self-rated symptoms in adult population samples show moderate heritability estimates of 30-40%. However, using multiple sources of information, the heritability of clinically diagnosed aADHD and cADHD is very similar. Results of candidate gene as well as genome-wide molecular genetic studies in aADHD samples implicate some of the same genes involved in ADHD in children, although in some cases different alleles and different genes may be responsible for adult versus childhood ADHD. Linkage studies have been successful in identifying loci for aADHD and led to the identification of LPHN3 and CDH13 as novel genes associated with ADHD across the lifespan. In addition, studies of rare genetic variants have identified probable causative mutations for aADHD. Use of endophenotypes based on neuropsychology and neuroimaging, as well as next-generation genome analysis and improved statistical and bioinformatic analysis methods hold the promise of identifying additional genetic variants involved in disease etiology. Large, international collaborations have paved the way for well-powered studies. Progress in identifying aADHD risk genes may provide us with tools for the prediction of disease progression in the clinic and better treatment, and ultimately may help to prevent persistence of ADHD into adulthood.

Dopaminergic system genes in childhood aggression: possible role for DRD2

Excessive or deficient levels of extracellular dopamine have been hypothesized to contribute to a broad spectrum of mood, motor, and thought abnormalities, and dopaminergic system genes have been implicated in aggressive behaviour from animal and human studies. OBJECTIVE. We examined selected members of the dopaminergic system genes for association with child aggression.

METHOD

We analyzed polymorphisms in the dopamine transporter DAT1/SLC6A3, dopamine receptor DRD2, and DRD4 genes in our sample of pervasive childhood aggression consisting of 144 cases paired with 144 healthy controls, matched for sex and ethnicity.

RESULTS

Aggressive children were significantly more likely to have the at least one copy of the G allele for the DRD2 A-241G polymorphism (genotypic P=0.02; allelic P=0.01). The DRD2 rs1079598 CC genotype was overrepresented in aggressive children compared to controls (genotype P=0.04). The DRD2 TaqIA T allele (P=0.01) and the TT genotype (P=0.01) were also significantly overrepresented in aggressive children.

CONCLUSIONS

Our preliminary results suggest that three polymorphisms in DRD2 are associated with childhood aggression. Future studies are required to replicate the current results and to further explore the relationship between the dopamine system and aggressive behaviour in children.

Genetic and environmental influences on psychiatric comorbidity: a systematic review

BACKGROUND

The purpose of this review is to systematically appraise the peer-reviewed literature about the genetic and environmental determinants of psychiatric comorbidity, focusing on four of the most prevalent types of psychopathology: anxiety disorders, depression, conduct disorder and substance abuse.

METHODS

We summarize existing empirical research on the relative contribution that genetic, nonshared and shared environmental factors make to the covariance between disorders, and evidence about specific genes and environmental characteristics that are associated with comorbidity.

RESULTS

Ninety-four articles met the inclusion criteria and were assessed. Genetic factors play a particularly strong role in comorbidity between major depression and generalized anxiety disorder or posttraumatic stress disorder, while the non-shared environments make an important contribution to comorbidity in affective disorders. Genetic and non-shared environmental factors also make a moderate-to-strong contribution to the relationship between CD and SA. A range of candidate genes, such as 5HTTLPR, MAOA, and DRD1-DRD4, as well as others implicated in the central nervous system, has been implicated in psychiatric comorbidity. Pivotal social factors include childhood adversity/life events, family and peer social connections, and socioeconomic and academic difficulties.

LIMITATIONS

Methodological concerns include the use of clinical case-control samples, the focus on a restricted set of individual-level environmental risk factors, and restricted follow-up times.

CONCLUSIONS

Given the significant mental health burden associated with comorbid disorders, population-based research on modifiable risk factors for psychiatric comorbidity is vital for the design of effective preventive and clinical interventions.

Molecular genetics of attention deficit hyperactivity disorder

Although twin studies demonstrate that ADHD is a highly heritable condition, molecular genetic studies suggest that the genetic architecture of ADHD is complex. The handful of genome-wide linkage and association scans that have been conducted thus far show divergent findings and are, therefore, not conclusive. Similarly, many of the candidate genes reviewed here (ie, DBH, MAOA, SLC6A2, TPH-2, SLC6A4, CHRNA4, GRIN2A) are theoretically compelling from neurobiological systems perspective but available data are sparse and inconsistent. However, candidate gene studies of ADHD have produced substantial evidence implicating several genes in the etiology of the disorder, with meta-analyses supportive of a role of the genes coding for DRD4, DRD5, SLC6A3, SNAP-25, and HTR1B in the etiology of ADHD.

Impulsivity, frontal lobes and risk for addiction

Alcohol and substance abuse disorders involve continued use of substances despite negative consequences, i.e. loss of behavioral control of drug use. The frontal-cortical areas of the brain oversee behavioral control through executive functions. Executive functions include abstract thinking, motivation, planning, attention to tasks and inhibition of impulsive responses. Impulsiveness generally refers to premature, unduly risky, poorly conceived actions. Dysfunctional impulsivity includes deficits in attention, lack of reflection and/or insensitivity to consequences, all of which occur in addiction [Evenden JL. Varieties of impulsivity. Psychopharmacology (Berl) 1999;146:348-361.; de Wit H. Impulsivity as a determinant and consequence of drug use: a review of underlying processes. Addict Biol 2009;14:22-31]. Binge drinking models indicate chronic alcohol damages in the corticolimbic brain regions [Crews FT, Braun CJ, Hoplight B, Switzer III RC, Knapp DJ. Binge ethanol consumption causes differential brain damage in young adolescent rats compared with adult rats. Alcohol Clin Exp Res 2000;24:1712-1723] causing reversal learning deficits indicative of loss of executive function [Obernier JA, White AM, Swartzwelder HS, Crews FT. Cognitive deficits and CNS damage after a 4-day binge ethanol exposure in rats. Pharmacol Biochem Behav 2002b;72:521-532]. Genetics and adolescent age are risk factors for alcoholism that coincide with sensitivity to alcohol-induced neurotoxicity. Cortical degeneration from alcohol abuse may increase impulsivity contributing to the development, persistence and severity of alcohol use disorders. Interestingly, abstinence results in bursts of neurogenesis and brain regrowth [Crews FT, Nixon K. Mechanisms of neurodegeneration and regeneration in alcoholism. Alcohol Alcohol 2009;44:115-127]. Treatments for alcoholism, including naltrexone pharmacotherapy and psychotherapy may work through improving executive functions. This review will examine the relationships between impulsivity and executive function behaviors to changes in cortical structure during alcohol dependence and recovery.

Genetic and non-genetic influences on the development of co-occurring alcohol problem use and internalizing symptomatology in adolescence: a review

AIMS

Alcohol problem use during adolescence has been linked to a variety of adverse consequences, including cigarette and illicit drug use, delinquency, adverse effects on pubertal brain development and increased risk of morbidity and mortality. In addition, heavy alcohol-drinking adolescents are at increased risk of comorbid psychopathology, including internalizing symptomatology (especially depression and anxiety). A range of genetic and non-genetic factors have been implicated in both alcohol problem use as well as internalizing symptomatology. However, to what extent shared risk factors contribute to their comorbidity in adolescence is poorly understood.

DESIGN

We conducted a systematic review on Medline, PsycINFO, Embase and Web of Science to identify epidemiological and molecular genetic studies published between November 1997 and November 2007 that examined risk factors that may be shared in common between alcohol problem use and internalizing symptomatology in adolescence.

FINDINGS

Externalizing disorders, family alcohol problems and stress, as well as the serotonin transporter (5-HTT) S-allele, the monoamine oxidase A (MAOA) low-activity alleles and the dopamine D2 receptor (DDR2) Taq A1 allele have been associated most frequently with both traits. An increasing number of papers are focusing upon the role of gene-gene (epistasis) and gene-environment interactions in the development of comorbid alcohol problem use and internalizing symptomatology.

CONCLUSIONS

Further research in adolescents is warranted; the increasing availability of large longitudinal genetically informative studies will provide the evidence base from which effective prevention and intervention strategies for comorbid alcohol problems and internalizing symptomatology can be developed.

The association between attention-deficit/hyperactivity disorder and early-onset alcohol dependence: A retrospective study

BACKGROUND

Early onset (EO) alcohol dependence (AD) has been found to represent a subtype of alcoholism with a distinct profile and prognosis compared to late onset (LO) alcohol dependence. Externalizing disorders, especially attention deficit hyperactivity disorder (ADHD) that may continue as attention deficit hyperactivity disorder, residual type (ADD, RT) in adulthood, may increase susceptibility to early-onset AD.

AIMS

To examine the relationship between ADHD and ADD, RT symptoms and age at onset of AD in a sample of Indian male patients. 70 male subjects with AD presenting to the De-Addiction Services of the National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, were studied. The study had a retrospective design.

MATERIALS AND METHODS

Patients were examined for evidence of past ADHD in childhood and current ADD, RT using structured instruments. Chi-square tests and odds ratios were used to express the relative risk of association of ADHD with early- and late-onset AD.

RESULTS

Significantly more EO alcoholics (19/30, 63.3%) had a history of ADHD in childhood compared to LO alcoholics (7/28, 25%, P < 0.05) ADD, RT was also over-represented in EO probands.

CONCLUSIONS

The results of this study are consistent with previous research that shows a high incidence of ADHD in early-onset alcoholics. This may have important management implications.

Correlates of co-occurring ADHD in drug-dependent subjects: prevalence and features of substance dependence and psychiatric disorders

We examined the prevalence and course of psychiatric and substance dependence (SD) disorders in subjects with SD and attention deficit hyperactivity disorder (ADHD).

METHOD

We interviewed 1761 adults with a lifetime diagnosis of cocaine and/or opioid dependence using the Semi-Structured Assessment for Drug Dependence and Alcoholism. Generalized linear regression with generalized estimating equation analysis was used to examine the associations between a lifetime diagnosis of ADHD and indicators of clinical course, and to identify unique correlates of ADHD.

RESULTS

Lifetime ADHD prevalence in the SD sample was 5.22% (vs. 0.85% in a group of individuals without SD). ADHD was associated with an earlier age of first substance use, more SD and psychiatric diagnoses, a greater likelihood of attempted suicide, and more hospitalizations. After controlling for conduct disorder, there were unique effects of ADHD on age of first substance use and number of SD diagnoses.

CONCLUSION

In subjects with cocaine or opioid dependence, ADHD is associated with greater SD and psychiatric comorbidity and a more severe course of illness.

Genetics of attention deficit hyperactivity disorder

Results of behavioral genetic and molecular genetic studies have converged to suggest that both genetic and nongenetic factors contribute to the development of attention deficit hyperactivity disorder (ADHD). Family, twin, and adoption studies provide compelling evidence that genes play a strong role in mediating susceptibility to ADHD. In contrast to a handful of genome-wide scans conducted thus far, many candidate gene studies of ADHD have produced substantial evidence implicating several genes in the etiology of the disorder. Yet, even these associations are small and consistent with the idea that the genetic vulnerability to ADHD is mediated by many genes of small effects. These small effects emphasize the need for future candidate gene studies to implement strategies that will provide enough statistical power to detect such small effects.

Immediate reward bias in humans: fronto-parietal networks and a role for the catechol-O-methyltransferase 158(Val/Val) genotype

The tendency to choose lesser immediate benefits over greater long-term benefits characterizes alcoholism and other addictive disorders. However, despite its medical and socioeconomic importance, little is known about its neurobiological mechanisms. Brain regions that are activated when deciding between immediate or delayed rewards have been identified (McClure et al., 2004, 2007), as have areas in which responses to reward stimuli predict a paper-and-pencil measure of temporal discounting (Hariri et al., 2006). These studies assume "hot" and "cool" response selection systems, with the hot system proposed to generate impulsive choices in the presence of a proximate reward. However, to date, brain regions in which the magnitude of activity during decision making reliably predicts intertemporal choice behavior have not been identified. Here we address this question in sober alcoholics and non-substance-abusing control subjects and show that immediate reward bias directly scales with the magnitude of functional magnetic resonance imaging bold oxygen level-dependent (BOLD) signal during decision making at sites within the posterior parietal cortex (PPC), dorsal prefrontal cortex (dPFC), and rostral parahippocampal gyrus regions. Conversely, the tendency of an individual to wait for a larger, delayed reward correlates directly with BOLD signal in the lateral orbitofrontal cortex. In addition, genotype at the Val158Met polymorphism of the catechol-O-methyltransferase gene predicts both impulsive choice behavior and activity levels in the dPFC and PPC during decision making. These genotype effects remained significant after controlling for alcohol abuse history. These results shed new light on the neurobiological underpinnings of temporal discounting behavior and identify novel behavioral and neural consequences of genetic variation in dopamine metabolism.