DSM-IV and ICD-10: A Comparison of the Correlates of ADHD and Hyperkinetic Disorder

ObjectiveTo examine directly the extent to which ICD-10 hyperkinetic disorder and DSM-IV attention-deficit/hyperactivity disorder (ADHD) identify the same children with the same difficulties.MethodParticipants were children referred for symptoms of overactivity, inattention, and impulsivity, and a normal control group. Diagnostic criteria for ICD-10 hyperkinetic disorder and DSM-IV ADHD were applied retrospectively. Four groups were identified: hyperkinetic disorder and ADHD (n = 21), ADHD only (n = 22), clinic control (n = 15), and normal control (n = 19). The groups were compared on measures reflecting the central characteristics of ADHD, neurodevelopmental functioning, academic and cognitive functioning, and the presence of conduct problems.ResultsThere is some evidence of increased symptom severity in the combined diagnostic group. Few differences emerged on measures of neurodevelopmental, academic, and cognitive functioning. Rates of conduct disturbance were similar in both ADHD groups.ConclusionsDSM-IV criteria identify a broader group of children than those identified by ICD-10. However, there is substantial overlap between the groups formed with these different criteria.     

Genetic Heterogeneity Shapes Brain Connectivity in Psychiatry

BackgroundPolygenicity and genetic heterogeneity pose great challenges for studying psychiatric conditions. Genetically informed approaches have been implemented in neuroimaging studies to address this issue. However, the effects on functional connectivity of rare and common genetic risks for psychiatric disorders are largely unknown. Our objectives were to estimate and compare the effect sizes on brain connectivity of psychiatric genomic risk factors with various levels of complexity: oligogenic copy number variants (CNVs), multigenic CNVs, and polygenic risk scores (PRSs) as well as idiopathic psychiatric conditions and traits.MethodsResting-state functional magnetic resonance imaging data were processed using the same pipeline across 9 datasets. Twenty-nine connectome-wide association studies were performed to characterize the effects of 15 CNVs (1003 carriers), 7 PRSs, 4 idiopathic psychiatric conditions (1022 individuals with autism, schizophrenia, bipolar conditions, or attention-deficit/hyperactivity disorder), and 2 traits (31,424 unaffected control subjects).ResultsEffect sizes on connectivity were largest for psychiatric CNVs (estimates: 0.2–0.65 z score), followed by psychiatric conditions (0.15–0.42), neuroticism and fluid intelligence (0.02–0.03), and PRSs (0.01–0.02). Effect sizes of CNVs on connectivity were correlated to their effects on cognition and risk for disease (r = 0.9, p = 5.93 × 10^?6). However, effect sizes of CNVs adjusted for the number of genes significantly decreased from small oligogenic to large multigenic CNVs (r = ?0.88, p = 8.78 × 10^?6). PRSs had disproportionately low effect sizes on connectivity compared with CNVs conferring similar risk for disease.ConclusionsHeterogeneity and polygenicity affect our ability to detect brain connectivity alterations underlying psychiatric manifestations.     

Phenome-wide Association Analysis of Substance Use Disorders in a Deeply Phenotyped Sample

BackgroundSubstance use disorders (SUDs) are associated with a variety of co-occurring psychiatric disorders and other SUDs, which partly reflects genetic pleiotropy. Polygenic risk scores (PRSs) and phenome-wide association studies are useful in evaluating pleiotropic effects. However, the comparatively low prevalence of SUDs in population samples and the lack of detailed information available in electronic health records limit these data sets’ informativeness for such analyses.MethodsWe used the deeply phenotyped Yale-Penn sample (n = 10,610 with genetic data; 46.3% African ancestry, 53.7% European ancestry) to examine pleiotropy for 4 major substance-related traits: alcohol use disorder, opioid use disorder, smoking initiation, and lifetime cannabis use. The sample includes both affected and control subjects interviewed using the Semi-Structured Assessment for Drug Dependence and Alcoholism, a comprehensive psychiatric interview.ResultsIn African ancestry individuals, PRS for alcohol use disorder, and in European individuals, PRS for alcohol use disorder, opioid use disorder, and smoking initiation were associated with their respective primary DSM diagnoses. These PRSs were also associated with additional phenotypes involving the same substance. Phenome-wide association study analyses of PRS in European individuals identified associations across multiple phenotypic domains, including phenotypes not commonly assessed in phenome-wide association study analyses, such as family environment and early childhood experiences.ConclusionsSmaller, deeply phenotyped samples can complement large biobank genetic studies with limited phenotyping by providing greater phenotypic granularity. These efforts allow associations to be identified between specific features of disorders and genetic liability for SUDs, which help to inform our understanding of the pleiotropic pathways underlying them.     

A Pilot Controlled Family Study of DSM-III-R and DSM-IV ADHD in African-American Children

BackgroundVery little is known about attention-deficit hyperactivity disorder (ADHD) in African-American children, and although the familial transmission of ADHD has been well established in white samples, prior work has not evaluated this feature of ADHD in African-American families.MethodSubjects were 37 first-degree relatives of children with DSM-III-R-defined ADHD and 52 first-degree relatives of non-ADHD comparison children matched for ethnicity, age, and gender. DSM-III-R-based structured interviews (modified to include DSM-IV diagnoses) provided the basis for psychiatric diagnoses in relatives.ResultsThe risks for both DSM-III-R and DSM-IV ADHD were significantly greater in first-degree relatives of ADHD probands than in relatives of controls. In addition, the relatives of ADHD probands also were at higher risk for oppositional defiant disorder, antisocial personality disorder, major depression, generalized anxiety, and substance use disorders.ConclusionsThese results suggest that ADHD and related disorders are familial in African-Americans. Further work is needed to confirm the familial transmission of ADHD in African-American children and to explore the role of genetics as well as environmental factors in the transmission of the disorder. J. Am. Acad. Child Adolesc. Psychiatry, 1999, 38(1):034–39.     

Characteristics and comorbidity of ADHD sib pairs in the Central Valley of Costa Rica

BackgroundWhile genetic epidemiological studies demonstrate a substantial degree of genetic predisposition for attention-deficit/hyperactivity disorder (ADHD), they also suggest that the genetics are complex and may differ between populations or ethnic groups.ObjectiveThis study describes the phenomenology of siblings with ADHD from the genetically isolated population of the Central Valley of Costa Rica.MethodsRates of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)–defined ADHD subtypes and comorbid conditions were calculated in a sample of 157 ADHD-affected children (probands and siblings) recruited for genetic studies using standardized approaches. Sib-sib comparisons and logistic regressions were conducted to identify significant patterns of concordance.ResultsCombined-type ADHD (69.5%) was the most common subtype among probands, followed by the inattentive (27.4%), and hyperactive-impulsive (3.2%) subtypes. Anxiety disorders were prevalent (55.9%), as were disruptive behavior disorders (30.9%) and Tourette disorder (17.0%). Probands and siblings showed high sib-sib concordance for anxiety disorders.ConclusionsADHD in Costa Rica is similar in clinical and demographic characteristics to ADHD seen in other parts of the world, although the rates of co-occurring psychiatric disorders differ somewhat from those previously reported in Latin American samples. Comorbid anxiety is prevalent, with high rates of sib-sib concordance, and may represent a distinct, homogeneous subgroup suitable for genetic studies.     

New insights into the comorbidity between ADHD and major depression in adolescent and young adult females

ObjectiveThe main aim of this study was to evaluate the association between attention-deficit/hyperactivity disorder (ADHD) and major depression (MD) in adolescent and young adult females.MethodSubjects were females with (n = 140) and without (n = 122) ADHD ascertained from pediatric and psychiatric settings. Subjects were followed prospectively for 5 years into adolescence and young adulthood and reassessed in multiple nonoverlapping domains including psychiatric, cognitive, interpersonal, family, and educational functioning.ResultsFemales with ADHD had a 2.5 times higher risk for MD at adolescent follow-up compared with control females, adjusting for psychiatric comorbidity. MD in females with ADHD was associated with an earlier age at onset, greater than twice the duration, more severe depression-associated impairment, a higher rate of suicidality, and a greater likelihood of requiring psychiatric hospitalization than MD in control girls. Parental MD and proband mania were significant predictors of MD among females with ADHD, independently of other predictors.ConclusionsMD emerging in the context of ADHD in females is an impairing and severe comorbidity worthy of further clinical and scientific considerations.     

Examining the nature of the comorbidity between pediatric attention deficit/hyperactivity disorder and post‐traumatic stress disorder

Biederman J, Petty CR, Spencer TJ, Woodworth KY, Bhide P, Zhu J, Faraone SV. Examining the nature of the comorbidity between pediatric attention deficit/hyperactivity disorder and post‐traumatic stress disorder. Objective: This study sought to address the link between attention deficit/hyperactivity disorder (ADHD) and post‐traumatic stress disorder (PTSD) in youth by providing a comprehensive comparison of clinical correlates of ADHD subjects with and without PTSD across multiple non‐overlapping domains of functioning and familial patterns of transmission. Method: Participants were 271 youths with ADHD and 230 controls without ADHD of both sexes along with their siblings. Participants completed a large battery of measures designed to assess psychiatric comorbidity, psychosocial, educational, and cognitive parameters. Results: Post‐traumatic stress disorder was significantly higher in ADHD probands vs. controls (5.2% vs. 1.7%, χ²₍₁₎ = 4.36, P = 0.04). Irrespective of the comorbidity with PTSD, ADHD subjects had similar ages at onset of ADHD, similar type and mean number of ADHD symptoms, and similar ADHD‐associated impairments. PTSD in ADHD probands was significantly associated with a higher risk of psychiatric hospitalization, school impairment, poorer social functioning and higher prevalences of mood, conduct disorder, and anxiety disorders. The mean onset of PTSD (12.6 years) was significantly later than that of ADHD and comorbid disorders (all P < 0.05). Siblings of ADHD and ADHD + PTSD probands had higher prevalences of ADHD vs. siblings of controls (35% vs. 18%, z = 4.00, P < 0.001 and 67% vs. 18%, z = 4.02, P < 0.001 respectively) and siblings of ADHD+PTSD probands had a significantly higher prevalence of PTSD compared with the siblings of ADHD and control probands (20% vs. 3% and 3%, z = 2.99, P = 0.003 and z = 2.07, P = 0.04 respectively). Conclusion: Findings indicate that the comorbidity with PTSD in ADHD leads to greater clinical severity as regards psychiatric comorbidity and psychosocial dysfunction. ADHD is equally familial in the presence of PTSD in the proband indicating that their co‐occurrence is not owing to diagnostic error.     

Evidence that genetic variation in the oxytocin receptor (OXTR) gene influences social cognition in ADHD

Some children with ADHD also have social and communication difficulties similar to those seen in children with autistic spectrum disorders and this may be due to shared genetic liability. As the oxytocin receptor (OXTR) gene has been implicated in social cognition and autistic spectrum disorders, this study investigated whether OXTR polymorphisms previously implicated in autism were associated with ADHD and whether they influenced OXTR mRNA expression in 27 normal human amygdala brain samples. The family-based association sample consisted of 450 DSM-IV diagnosed ADHD probands and their parents. Although there was no association with the ADHD phenotype, an association with social cognitive impairments in a subset of the ADHD probands (N = 112) was found for SNP rs53576 (F = 5.24, p = 0.007) with post-hoc tests demonstrating that the AA genotype was associated with better social ability compared to the AG genotype. Additionally, significant association was also found for rs13316193 (F = 3.09, p = 0.05) with post-hoc tests demonstrating that the CC genotype was significantly associated with poorer social ability than the TT genotype. No significant association between genotype and OXTR mRNA expression was found. This study supports previous evidence that the OXTR gene is implicated in social cognition.     

Association between binge eating disorder and psychiatric comorbidity profiles in patients with obesity seeking bariatric surgery

BackgroundEating disorders could be an important factor in the development of obesity, but psychiatric comorbidities are very heterogeneous in patients with obesity. Moreover, relationship between binge eating disorder and other psychiatric comorbidities is not clear. Our objective was to identify psychiatric comorbidity profiles of bariatric surgery candidates and to analyze the association between these profiles and binge-eating disorder.MethodsOur sample consisted of bariatric surgery candidates (n = 92) with mean Body Mass Index at 41.3 ± 0.6 kg/m². To construct profiles, we classified patients according to their psychiatric comorbidities using cluster analysis techniques. We used logistic regression modelling to analyze associations between the presence of binge-eating disorder and the psychiatric comorbidity profiles.ResultsWe identified four profiles of psychiatric phenotypes. One of these profiles was not associated with any psychiatric disorder. Binge eating disorder was significantly associated with two profiles (p < 0.05): a profile with bipolar and obsessive-compulsive disorder (OR = 7.7 [1.7; 35.1]), and a profile with bipolar and panic disorder (OR = 20.7 [3.1; 137.5]).ConclusionsOur multidimensional approach identified certain profiles specifically associated with binge-eating disorder in patients with obesity seeking bariatric surgery. These results may lead to a better understanding of the relationship between obesity and psychiatric disorders.     

Diagnostic profiles of adult psychiatric outpatients with and without attention deficit hyperactivity disorder

ObjectiveDespite growing recognition that attention deficit/hyperactivity disorder (ADHD) is a highly prevalent, impairing, and comorbid disorder that persists into adulthood, reports on the nature and extent of its psychiatric comorbidities have been mixed to date. This study compared the prevalence rates of all major Axis I disorders as well as borderline personality disorder in an unselected sample of adult psychiatric outpatients with and without ADHD.MethodsAs part of the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, we administered a DSM-IV-based semi-structured diagnostic interview assessing ADHD and other psychiatric disorders to 1134 patients presenting for initial evaluation at an outpatient psychiatric practice. Logistic regression analyses were used to compare the rates of each disorder in patients with versus without an ADHD diagnosis (both overall and by Combined and Inattentive type).ResultsPatients with (versus without) any ADHD diagnosis had significantly higher rates of bipolar disorder, social phobia, impulse control disorders, eating disorders, and BPD, and significantly lower rates of major depressive disorder and adjustment disorder (all p < .05). Patients with (versus without) ADHD-Inattentive type had significantly higher rates of social phobia and eating disorders, whereas those with (versus without) the ADHD-Combined type had significantly higher rates of bipolar disorder, alcohol dependence, and BPD (all p < .05).ConclusionIn this novel investigation of the psychiatric profiles of an unselected sample of treatment-seeking adult outpatients with versus without ADHD, a distinct pattern of comorbidities emerged across subtypes, with implications for the accurate assessment and treatment of patients presenting for psychiatric care.     

Parsing the familiality of oppositional defiant disorder from that of conduct disorder: a familial risk analysis

Background

Family risk analysis can provide an improved understanding of the association between attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD), attending to the comorbidity with conduct disorder (CD).

Methods

We compared rates of psychiatric disorders in relatives of 78 control probands without ODD and CD (Control, N = 265), relatives of 10 control probands with ODD and without CD (ODD, N = 37), relatives of 19 ADHD probands without ODD and CD (ADHD, N = 71), relatives of 38 ADHD probands with ODD and without CD (ADHD + ODD, N = 130), and relatives of 50 ADHD probands with ODD and CD (ADHD + ODD + CD, N = 170).

Results

Rates of ADHD were significantly higher in all three ADHD groups compared to the Control group, while rates of ODD were significantly higher in all three ODD groups compared to the Control group. Evidence for co-segregation was found in the ADHD + ODD group. Rates of mood disorders, anxiety disorders, and addictions in the relatives were significantly elevated only in the ADHD + ODD + CD group.

Conclusions

ADHD and ODD are familial disorders, and ADHD plus ODD outside the context of CD may mark a familial subtype of ADHD. ODD and CD confer different familial risks, providing further support for the hypothesis that ODD and CD are separate disorders.     

TDAH dans l’enfance et trouble psychotique à l’âge adulte : quel lien ?

ObjectivesAttention Deficit with/without Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder with frequent comorbid psychiatric disorders. Several studies have underlined the increased risk of developing a psychotic disorder subsequent to a childhood ADHD. The aim of our review is not only to clarify this association and the related physiopathology but also to understand the consequences for therapeutic management.MethodsWe processed a narrative review of available literature based on a research of the PubMed database. Articles related to ADHD and psychotic disorder on a genetical, clinical or biological level were selected by one of the authors.ResultsADHD and psychotic disorders share neonatal, environmental, and genetic risk factors. On a neurobiological level, both disorders are concerned by a dysfunction of the dopaminergic system with an abnormal regulation of dopaminergic neurons’ phasic and tonic activity. Our review aims to explain the « dynamic » model of dopaminergic dysfunctions and propose some guidance for pharmacological treatment of ADHD, with or without psychotic disorder. This model offers a better understanding of why methylphenidate is not associated to an increased risk of psychotic disorder and could act as a protective factor. Association between ADHD and psychotic disorders could be explained by some comorbidities such as substance use disorders which are frequently associated with both conditions and could act as mediator in the genesis of psychotic disorders following ADHD during childhood. Our review also focuses on an epidemiological bias that could be found in some studies such as possible diagnostic errors, as some non-specific clinical signs could be found in both late diagnosed ADHD and in “at risk mental state” of psychosis.ConclusionADHD and psychotic disorders share common risk factors, neurobiological pathways and clinical symptoms. Perspectives for future studies are proposed considering a dimensional aspect of psychiatric disorders using, for example, Research Domain Criteria and exploring the link between the two conditions.     

Comorbid psychiatric disorders in Arab children with Autism spectrum disorders

The objective of our study is to estimate the prevalence of comorbid psychiatric disorders in a sample of children with autism spectrum disorders (ASD) recruited from three Arab countries. We also examine the relationship between comorbidity and children's cognitive functioning and gender. Children who received a diagnosis of ASD (n = 60) from a child psychiatric outpatient clinic in Mansoura (Egypt), Al-Ahsa (Saudi Arabia) and Amman (Jordan) were included in this study. Comorbid diagnoses were established with a clinical interview and a semi-structured clinical interview for children and adolescents (SCICA). In addition, for all patients the cognitive evaluation was measured given the range in age and level of ability. Sixty-three percent of the children were diagnosed with at least one comorbid disorder. The most commonly reported comorbid disorders were anxiety disorders (58.3%), ADHD (31.6%), conduct disorders (23.3%), and major depressive disorder (13.3%). Out of the total sample, Obsessive compulsive disorder was the most prevalent anxiety disorder (55%). Elimination disorders were also diagnosed in 40% of patients. These findings emphasize a wide variety of psychiatric comorbidity afflicting youth with ASD and may be important targets for intervention.     

Developmental and mental health risks among siblings of patients with autism spectrum disorder: a nationwide study

Studies have suggested that unaffected siblings of patients with autism spectrum disorder (ASD) have some other neurodevelopmental abnormalities. However, the risks of mental and developmental disorders have rarely been investigated among unaffected siblings. Using Taiwan’s National Health Insurance Research Database, 1304 unaffected siblings born between 1980 and 2010 with ASD probands and 13,040 age-/sex-/family structure-matched controls were included in our study and followed up from 1996 or birth to the end of 2011. Developmental delay, language delay, developmental coordination disorder, attention-deficit hyperactivity disorder (ADHD), anxiety disorders, disruptive behavior disorders, unipolar disorder, and bipolar disorder were identified during the follow-up period. Unaffected siblings were more likely to develop any developmental delay, developmental speech or language disorder, developmental coordination disorder, intelligence disability, ADHD, anxiety disorders, unipolar depression, and disruptive behavior disorders compared with the control group. Brothers of patients with ASD had a higher risk of neurodevelopmental abnormalities, ADHD, anxiety disorders, and disruptive behavior disorders; sisters were prone to having neurodevelopmental abnormalities, ADHD, anxiety disorders, unipolar depression, and disruptive behavior disorders. Unaffected siblings of patients with ASD were prone to developing any developmental or mental disorder later in life. Clinicians and public health officials should pay more attention to the developmental condition and mental health of unaffected siblings of patients with ASD.

     

5-羟色胺转运体基因多态与共患学习困难的儿童注意缺陷多动障碍的相关性

目的探讨共患学习困难(LD)的注意缺陷多动障碍(ADHD)患儿与5-羟色胺转运体(5-HTT)基因连锁多态区(5-HTTLPR)和第2内含子17 bp数目可变的顺向重复(stin2.VNTR)的关联关系。方法对126例共患LD的ADHD患儿和198例不共患LD的ADHD患儿的5-HTTLPR和stin2.VNTR两种多态进行检测,并采用传递不平衡检测(TDT)和单体型分析方法进行关联分析。结果(1)TDT检测:5-HTTLPR多态的S等位基因在共患LD的ADHD和ADHD混合型(ADHD-C)核心家系中优先传递(X2=5.831和5.281,P=0.015和0.020);所有家系均未观察到stin2.VNTR多态中的任何等位基因有传递不平衡现象(均P>0.05);(2)单体型分析:5-HTT基因与共患LD的ADHD和ADHD-C相关联(X2=11.391和13.343,v=3,P=0.010和P=0.004);单体型L／12在共患LD的ADHD和ADHD-C核心家系中传递较少(X2=10.317和8.948,v=1,P=0.001和0.003),而单体型L／10在共患LD的ADHD核心家系中传递较多(X2=4.065,v=1,P=0.044)。结论5-HTT基因可能与共患LD的ADHD相关联,其中主要为共患LD的ADHD-C亚型。     

PSYCHIATRIC ASPECTS OF ADOLESCENT OFFENDING: A REVIEW OF RECENT STUDIES

Abstract

Delinquency and conduct disorder have been predominantly ascribed to psychosocial influences. Data consistently confirm that offending behaviour in adolescents often occurs together with, or as an expression of substance abuse, mood disorders, ADHD and possibly psychosis. However the specific connections between offending and psychiatric symptoms remain to be elucidated. Research into genetic bases and biological markers of adolescent offending has begun to uncover the complicated interactions between nature and nurture.     

Polygenic risk for type 2 diabetes mellitus among individuals with psychosis and their relatives

BackgroundAn elevated prevalence of Type 2 diabetes (T2D) has been observed in people with psychotic disorders and their relatives compared to the general population. It is not known whether this population also has increased genetic risk for T2D.MethodsSubjects included probands with schizophrenia, schizoaffective disorder, or psychotic bipolar I disorder, their first-degree relatives without psychotic disorders, and healthy controls, who participated in the Bipolar Schizophrenia Network for Intermediate Phenotypes study. We constructed sets of polygenic risk scores for T2D (PGRS_T2D) and schizophrenia (PGRS_SCHIZ) using publicly available data from genome-wide association studies. We then explored the correlation of PGRS_T2D with psychiatric proband or relative status, and with self-reported diabetes. Caucasians and African–Americans were analyzed separately. We also evaluated correlations between PGRS_SCHIZ and diabetes mellitus among Caucasian probands and their relatives.ResultsIn Caucasians, PGRS_T2D was correlated with self-reported diabetes mellitus within probands, but was not correlated with proband or relative status in the whole sample. In African–Americans, a PGRS_T2D based on selected risk alleles for T2D in this population did not correlate with proband or relative status. PGRS_SCHIZ was not correlated with self-reported diabetes within Caucasian probands.ConclusionDifferences in polygenic risk for T2D do not explain the increased prevalence of diabetes mellitus observed in psychosis probands and their relatives.     

Cognitive Functioning in Psychiatric Disorders Following Deep Brain Stimulation

BackgroundDeep brain stimulation (DBS) is routinely used as a treatment for treatment-refractory Parkinson's disease and has recently been proposed for psychiatric disorders such as Tourette syndrome (TS), obsessive-compulsive disorder (OCD) and major depressive disorder (MDD). Although cognitive deterioration has repeatedly been shown in patients with Parkinson's disease following DBS, the impact of DBS on cognitive functioning in psychiatric patients has not yet been reviewed.ObjectiveReviewing the available literature on cognitive functioning following DBS in psychiatric patients.MethodsA systematic literature search in PubMed, EMBASE and Web of Science, last updated in September 2012, found 1470 papers. Abstracts were scrutinized and 26 studies examining cognitive functioning of psychiatric patients following DBS were included on basis of predetermined inclusion criteria.ResultsTwenty-six studies reported cognitive functioning of 130 psychiatric patients following DBS (37 TS patients, 56 OCD patients, 28 MDD patients, 6 patients with Alzheimer's disease, and 3 patients with other disorders). None of the studies reported substantial cognitive decline following DBS. On the contrary, 13 studies reported cognitive improvement following DBS.ConclusionPreliminary results suggest that DBS in psychiatric disorders does not lead to cognitive decline. In selected cases cognitive functioning was improved following DBS. However, cognitive improvement cannot be conclusively attributed to DBS since studies are hampered by serious limitations. We discuss the outcomes in light of these limitations and offer suggestions for future work.     

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.