Ages of onset and rates of syndromal and subsyndromal comorbid DSM-IV diagnoses in a prepubertal and early adolescent bipolar disorder phenotype

OBJECTIVE: To study rates and ages of onset of DSM-IV syndromal and subsyndromal comorbidity in a prepubertal and early adolescent bipolar disorder phenotype (PEA-BP) (N = 93) compared to attention-deficit/hyperactivity disorder (ADHD) (N = 81). METHOD: The WASH-U-KSADS was given by raters blinded to subject group separately to mothers about their children and to children about themselves. PEA-BP was defined as DSM-IV mania with at least one cardinal symptom of mania (elation or grandiosity) to avoid diagnosing using only symptoms that overlapped with those for ADHD. Syndromal diagnoses required a CGAS score of 60 or less to ensure severity at a level of definite "caseness." RESULTS: PEA-BP subjects were aged 10.9 (SD = 2.6) at baseline and 6.8 (SD = 3.4) at onset of first mania episode. Rates of oppositional defiant disorder and total number of comorbidities were significantly higher in the PEA-BP group than the ADHD group. In PEA-BP subjects, mean ages of onset of ADHD occurred before the first manic episode, and obsessive compulsive, oppositional defiant, social phobia, generalized anxiety, separation anxiety, and conduct disorders occurred after. CONCLUSIONS: Onsets of ADHD before mania and of oppositional defiant disorder/conduct disorder after mania have clinical and research implications. These include the need to examine for mania symptoms in children with ADHD and/or oppositional defiant disorder/conduct disorder and to develop scales to differentiate preschool mania from ADHD. Comparison with other studies demonstrated the importance of DSM system and severity scales in reporting comorbidity rates.     

A systematic evaluation of ADHD and comorbid psychopathology in a population-based twin sample

OBJECTIVE: Clinical and population samples demonstrate that attention-deficit/hyperactivity disorder (ADHD) occurs with other disorders. Comorbid disorder clustering within ADHD subtypes is not well studied. METHOD: Latent class analysis (LCA) examined the co-occurrence of DSM-IV ADHD, oppositional defiant disorder (ODD), conduct disorder (CD), and depression symptoms in a population twin sample. The authors fit separate models for ADHD and comorbid disorder symptoms. Twin concordance ratios (monozygotic versus dizygotic) were compared examining genetic influence on class membership. RESULTS: LCA of ADHD symptoms resulted in seven classes including inattentive, combined, and hyperactive subtypes in 1,616 subjects. The few ADHD symptoms (53.4%) and severe inattentive (12.3%) classes were most frequent. LCA of ODD, CD, and depression symptoms in 1,587 subjects revealed five classes including ODD (19.4%), depression (14.5%), and two composite classes: ODD/CD (6.9%) and ODD/CD/depression (7.2%). Internalizing and externalizing comorbid disorders were present across all ADHD subtypes. Odds ratios (ORs) for twin concordance indicate genetic influence on severe inattentive (OR = 4.18; 95% confidence interval [CI], 1.52-11.53) and combined (OR = 5.25; 95% CI, 1.32-20.78) ADHD classes and ODD (OR = 1.49; 95% CI, 0.70-3.17), ODD/CD (OR = 3.32; 95% CI, 0.57-19.28), and ODD/CD/depression (OR = 1.20; 95% CI, 0.30-4.77) classes. CONCLUSIONS: Internalizing and externalizing disorders did not cluster differentially within ADHD subtypes. LCA may provide a more precise characterization of comorbidity with ADHD.     

Differential stimulant response on attention in children with comorbid anxiety and oppositional defiant disorder

Attention-deficit hyperactivity disorder (ADHD) affects 3% to 7% of school-age children. Approximately 30% of the children with ADHD also have comorbid anxiety or oppositional defiant disorder. Methylphenidate is the drug of choice for the medical treatment of such cases. When compared with children with ADHD alone, children with comorbid anxiety or oppositional defiant disorder may show worsening of the global attention score in response to methylphenidate and not only a "reduced response," as reported in previous studies. This study included 1122 children diagnosed as ADHD, of which 174 were diagnosed with comorbid anxiety and 141 with comorbid oppositional defiant disorder. All patients performed the Test of Variables of Attention before and after methylphenidate administration. A normal distribution (Gaussian distribution) of reaction to methylphenidate, as measured by the global ADHD score in children diagnosed as pure ADHD, was found. These findings were in contrast to children with ADHD and comorbid anxiety or oppositional defiant disorder who showed a bimodal distribution and hence represent a distinct population. In both groups with comorbid disorders, there was a larger subgroup in which significant worsening of global ADHD score occurred after methylphenidate administration (P < .05). Children with ADHD and comorbid anxiety or oppositional defiant disorder might represent clinically distinct populations in which inattention is secondary to those disorders; therefore, methylphenidate may be an inappropriate treatment for such children.     

Tourette syndrome in youth with and without obsessive compulsive disorder and attention deficit hyperactivity disorder

Chronic tic disorders (TD) are consistently found to have high rates of comorbidity with obsessive-compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD). The purpose of this study is to compare the severity of TD only to TD with comorbid OCD or ADHD based on severity of tics, measures of psychopathology and additional comorbid diagnoses. Baseline data from 158 youth with a chronic TD who participated in two longitudinal studies were examined. Fifty-three percent (N = 85) of the youth also met criteria for a diagnosis of OCD, 38.6 % (n = 61) met criteria for ADHD and 24.1 % (N = 38) met criteria for both. Measures of interest addressed severity of tics, symptoms of anxiety, depression, ADHD, psychosocial stress, global functioning and the presence of comorbid diagnoses. Youth with comorbid TD and OCD were characterized by more severe tics, increased levels of depressive and anxious symptoms, heightened psychosocial stress and poorer global functioning. Youth with comorbid TD and ADHD did not differ from those with TD alone on measures of tic severity, but experienced greater psychosocial stress and poorer global functioning. Subjects with comorbid TD and OCD had more internalizing disorders than those without OCD, while those with comorbid ADHD were more likely to meet criteria for oppositional defiant disorder. TD with OCD is a more severe subtype of TD than TD without OCD. TD with ADHD is associated with higher psychosocial stress and more externalizing behaviors. Further research is needed into the underlying relationships between these closely associated conditions.     

Sex and informant effects on diagnostic comorbidity in an adolescent community sample.

OBJECTIVE: To investigate sex and informant effects on comorbidity rates for anxiety disorders, depressive disorders, attention-deficit hyperactivity disorder (ADHD), and conduct-oppositional disorder (CD-ODD) in an adolescent community sample. METHOD: The Diagnostic Interview Schedule for Children-2.25 (DISC-2.25) was administered to 1201 adolescents and their mothers. RESULTS: The highest comorbidity risk found was between ADHD and CD-ODD, with odds ratios (ORs) of 17.6 for adolescent reports and 12.0 for mother reports. The second-highest comorbidity risk, with ORs of 13.2 for adolescent reports and 11.0 for mother reports, was between anxiety and depressive disorders. There was not much overlap between internalizing and externalizing disorders. Adolescent girls had higher rates of coexisting anxiety and depressive disorders, whereas adolescent boys had higher rates of coexisting ADHD and CD-ODD. There was partial support for the hypothesis that adolescent-reported comorbidity rates would exceed mother-reported rates. CONCLUSIONS: There is a greater cooccurrence of within-category, compared with between-category, disorders. Adolescent girls are more likely to have coexisting internalizing disorders, while adolescent boys are more likely to have coexisting externalizing disorders. Mothers tend to report more externalizing disorders (that is, ADHD), while adolescents generally report more internalizing disorders.     

Relationships between anxiety and externalizing disorders in youth: the influences of age and gender

Minimal information about the relationship between anxiety disorders and externalizing disorders in youth is available. This study examined relationships between different specific anxiety and externalizing disorders and examined whether these associations varied by age and gender. The Methods for the Epidemiology of Child and Adolescent Mental Disorders (MECA) data set, consisting of youth from ages 9 to 17 recruited at four sites across the United States using a probability sampling method, was used. Results indicated that all externalizing disorders (attention-deficit hyperactivity disorder, oppositional defiant disorder, and conduct disorder) were positively related to a range of anxiety disorders. The magnitude of these associations tended to be stronger for males than for females (particularly for associations between social phobia and all externalizing disorders) and at younger, compared to older, ages (particularly for the association between oppositional defiant disorder and overanxious disorder). The cross-sectional positive relationships between externalizing and anxiety disorders vary somewhat based on gender, age, and which specific pair of disorders is examined; this may help explain the discrepant findings of previous research in this area.     

Executive and intellectual functions in attention-deficit/hyperactivity disorder with and without comorbidity

Background: Recent neuropsychological theories have targeted deficient executive functions (EF) as the main characteristic of Attention Deficit Hyperactivity Disorder (ADHD), but the nature of the neuropsychological deficits remains elusive and findings are heterogeneous. In particular, it is still unclear whether ADHD subtypes and comorbidity affect intellectual and executive functioning, because large variability has been found in different patient populations. Furthermore, the role of IQ in EF deficits in individuals with ADHD has been debated. Methods: The aim of the present research was to study in detail the relationship between EF, ADHD subtypes, and comorbid diagnosis by taking into account the potential role of IQ. For this purpose, 23 children (aged from 5 to 16 years; 20 males and 3 females) with a diagnosis of ADHD were selected. Results: Data show no differences between children with different subtypes of ADHD on measures of EF, but they evidence differences on EF measures in children with different comorbidities (internalizing versus externalizing disorder). Namely, compared to the internalizing disorders group, the children with externalizing disorders obtained significantly lower scores on different measures of EF (i.e., verbal working memory and categorical fluency), but these differences were strictly dependent on IQ level. Conclusions: Comorbidity patterns, rather than ADHD subtypes, appear to be more valid for defining the neuropsychological features of the ADHD endophenotype. Moreover, general intelligence seems to play a substantial role in the cognitive processes underling the disorder, especially in relation to externalizing aspects.     

Psychiatric disorders in preschoolers: the structure of DSM-IV symptoms and profiles of comorbidity

Psychiatric disorders have been increasingly recognized in preschool children; at present, however, we know comparatively less about how well current diagnostic manuals capture the symptoms described in this age group and how comorbidity is patterned. Therefore, this study aimed to investigate whether the symptoms defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) load on their respective disorders, examine whether individual symptoms exist that load particularly high or low on the disorder they allegedly define, and analyze how comorbidity clusters in individual children. Parents of a community sample of Norwegian 4-year-olds (N = 995) were interviewed using the Preschool Age Psychiatric Assessment. A confirmatory factor analysis (CFA) and a latent profile analysis (LPA) were performed on the symptoms of seven DSM disorders: attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder, conduct disorder, major depressive disorder (MDD), generalized anxiety disorder (GAD), social phobia, and separation anxiety disorder. The results showed that the CFA solution that closely resembled the disorders delineated in the DSM-IV fitted the data best. However, vegetative symptoms did not define preschool depression. The LPA identified nine symptom profiles among preschoolers, of which four showed evidence of psychopathology: comorbid MDD/GAD + ADHD combined type, comorbid MDD/GAD + ADHD hyperactive/impulsive type, separation anxiety only, and social phobia only. In conclusion, the symptoms observed in preschoolers fit the DSM-IV well, and comorbidity followed specific patterns.     

Patterns of psychiatric comorbidity with attention-deficit/hyperactivity disorder

Attention deficit/hyperactivity disorder (ADHD) is frequently comorbid with a variety of psychiatric disorders. These disorders include oppositional defiant (ODD) and conduct disorders (CD), and affective, anxiety, and learning disorders. Studies which have examined the comorbidity of these disorders with ADHD are reviewed. ADHD and ADHD with CD seem to be distinct subtypes; children with ADHD/CD are at higher risk of antisocial personality as adults. Coexisting anxiety may attenuate impulsivity in ADHD. Studies examining stimulant response in children with ADHD/anxiety have recently yielded conflicting results. Anxiety and ADHD seem to be inherited independently. The prevalence of major depressive disorder (MDD) and bipolar disorder among children with ADHD is controversial, but there clearly exists a subgroup of severely emotionally labile children with ADHD who present serious management issues for the clinician. About 20% to 25% of children with ADHD meet criteria for a learning disorder (LD), but LD seems to be independent of ADHD.     

ODD and ADHD symptoms in Ukrainian children: external validators and comorbidity

OBJECTIVE: To examine potential external validators for oppositional defiant disorder (ODD) and attention-deficient/hyperactive disorder (ADHD) symptoms in a Ukrainian community-based sample of 600 children age 10 to 12 years old and evaluate the nature of co-occurring ODD and ADHD symptoms using mother- and teacher-defined groups. METHOD: In 1997, parents, children, and teachers participated in extensive clinical assessments using standard Western measures. Four areas of functioning were assessed: child mental health, parent-child interactions, parental well-being, and school/cognitive performance. RESULTS: Mother-defined ODD versus ADHD symptom groups were differentiated by a history of overactivity and tantrums, behavior in school, and maternal anxiety and hostility. Teacher-defined groups were differentiated by conduct problems, internalizing symptoms, mother-child interactions, and paternal alcohol use. The effects of co-occurring ODD and ADHD symptoms were greater than would be expected based on their separate effects for conduct problems, internalizing symptoms, social problems, academic performance, parent-child relations, and marital discord. CONCLUSIONS: Children with ODD versus ADHD symptoms were not significantly different from each other for the majority of variables examined, and group differences were dependent on the rater used to define symptom groups.     

What can ADHD without comorbidity teach us about comorbidity?

Neuropsychiatric comorbidity in ADHD is frequent, impairing and poorly understood. In this report, characteristics of comorbid and comorbid-free ADHD subjects are investigated in an attempt to identify differences that could potentially advance our understanding of risk factors.In a clinically-referred ADHD cohort of 449 youths (ages 6-18), age, gender, IQ, SES and ADHD symptoms were compared among ADHD comorbid free subjects and ADHD with internalizing and externalizing disorders. Logistic regression analyses were also carried out to investigate the relationship between comorbidity and parental psychiatric status.Age range was younger in the ADHD without comorbidity and older in ADHD + internalizing disorders. No significant difference in IQ or SES was found among ADHD comorbid and comorbid-free groups. ADHD with internalizing disorder has a significantly greater association with paternal psychiatric conditions. After matching by age, gender, IQ and SES, ADHD with externalizing disorders had significantly higher total ADHD, hyperactivity/impulsivity score and single item score of difficulty awaiting turn than ADHD without comorbidity and ADHD with internalizing disorders.Older age ranges, ADHD symptom severity and parental psychopathology may be risk factors for comorbidity.     

Psychiatric comorbidity in adult attention deficit hyperactivity disorder: findings from multiplex families

OBJECTIVE: Patterns of psychiatric comorbidity were assessed in adults with and without attention deficit hyperactivity disorder (ADHD) identified through a genetic study of families containing multiple children with ADHD. METHOD: Lifetime ADHD and comorbid psychopathology were assessed in 435 parents of children with ADHD. Rates and mean ages at onset of comorbid psychopathology were compared in parents with lifetime ADHD, parents with persistent ADHD, and those without ADHD. Age-adjusted rates of comorbidity were compared with Kaplan-Meier survival curves. Logistic regression was used to assess additional risk factors for conditions more frequent in ADHD subjects. RESULTS: The parents with ADHD were significantly more likely to be unskilled workers and less likely to have a college degree. ADHD subjects had more lifetime psychopathology; 87% had at least one and 56% had at least two other psychiatric disorders, compared with 64% and 27%, respectively, in non-ADHD subjects. ADHD was associated with greater disruptive behavior, substance use, and mood and anxiety disorders and with earlier onset of major depression, dysthymia, oppositional defiant disorder, and conduct disorder. Group differences based on Kaplan-Meier age-corrected risks were consistent with those for raw frequency distributions. Male sex added risk for disruptive behavior disorders. Female sex and oppositional defiant disorder contributed to risk for depression and anxiety. ADHD was not a significant risk factor for substance use disorders when male sex, disruptive behavior disorders, and socioeconomic status were controlled. CONCLUSIONS: Adult ADHD is associated with significant lifetime psychiatric comorbidity that is not explained by clinical referral bias.     

Psychiatric comorbidity associated with DSM-IV ADHD in a nonreferred sample of twins

OBJECTIVE: To test the external validity of the dimensions and subtypes of DSM-IV attention-deficit/hyperactivity disorder (ADHD) by assessing the prevalence of psychiatric comorbidity. METHOD: Eight- to 18-year-old twins with ADHD (n = 105) and without ADHD (n = 95) were recruited through local school districts. Comorbid disorders were assessed by structured diagnostic interviews with the parent and child and by a behavioral rating scale completed by the child's classroom teacher. RESULTS: Symptoms of inattention were associated with lower intelligence and higher levels of depression, whereas symptoms of hyperactivity-impulsivity were associated more strongly with symptoms of oppositional defiant disorder (ODD) and conduct disorder (CD). All DSM-IV subtypes were associated with higher rates of ODD and CD in comparison with controls, and the combined type was associated with more disruptive behavior disorder symptoms than the other 2 subtypes. The combined type and predominantly inattentive type were associated with more symptoms of depression than controls or the predominantly hyperactive-impulsive type. CONCLUSIONS: These results provide support for the discriminant validity of the dimensions and subtypes of DSM-IV ADHD and suggest that clinicians should carefully screen for comorbid disorders as part of a comprehensive assessment of ADHD.     

ADHD symptoms and subtypes: relationship between childhood and adolescent symptoms

OBJECTIVE: To study attention-deficit/hyperactivity disorder (ADHD) symptoms and DSM-IV subtypes in childhood and adolescence. METHOD: A total of 457 adolescents ages 16 to 18 years from the Northern Finland Birth Cohort 1986 participated in an epidemiological survey for ADHD. After assessment with a diagnostic interview those with current or childhood ADHD were classified using DSM-IV criteria. Childhood diagnosis of ADHD was set according to retrospective recall. The characteristics and relationships in ADHD symptomatology in childhood and adolescence were studied in relation to behavioral problems and parental history of attentional problems. RESULTS: ADHD was reported more commonly in childhood than in adolescence and variations in subtype classification occurred. Those with childhood and adolescent diagnosis had endorsed specific inattentive symptoms more commonly, had greater comorbid major depression and/or oppositional defiant disorder, and had fathers with more reported attentional problems than those with only childhood diagnosis. In childhood, ADHD subtypes differed along symptom severity, but by adolescence these differences were no longer significant. CONCLUSIONS: The persistence of ADHD from childhood to adolescence may be common. Specific inattentive symptoms, certain psychiatric comorbidity, and family history of attention problems (fathers specifically) contribute to the risk of persistent ADHD. ADHD subtype differences reflect symptom severity differences in childhood that are negligible by adolescence.     

Predictors of different types of developmental coordination problems in ADHD: the effect of age, gender, ADHD symptom severity and comorbidities

It is known that developmental coordination problems in children with ADHD are very common. However, it is not clear whether different subtypes of coordination problems are associated with ADHD comorbidities, inattentiveness severity, and impulsivity/hyperactivity severity. A clinical sample of 122 children and adolescents with ADHD and their parents were interviewed. The parents completed the validated and reliable Farsi version of DCD-Q regarding their children. The internal reliability of the DCD-Q was high for the full scale and the subscales. The confirmatory factor analysis indicated that the fit for the hypothesized factor structure of the DCD-Q was poor. Linear regression analysis indicated that the scores of validated DCD-Q in children with ADHD, except for the fine motor/hand writing score, were not predicted by the variables of gender, handedness, age, inattentiveness score, hyperactivity/impulsivity score, and oppositional defiant behavior score. The fit for the hypothesized factor structure of the DCD-Q is poor in children with ADHD. Fine motor/hand writing was predicted by inattention severity. The other subtypes of developmental coordination problems in children with ADHD cannot be attributed to the variables of gender, inattentiveness severity, hyperactivity/impulsivity severity, comorbidity with separation anxiety symptoms and oppositional defiant behavior score, and handedness.     

Psychiatric disorders and behavioral characteristics of pediatric patients with both epilepsy and attention-deficit hyperactivity disorder

OBJECTIVE: Attention-deficit hyperactivity disorder (ADHD) coexisting with epilepsy is poorly understood; thus, we compared the clinical correlates and psychiatric comorbid conditions of 36 children with epilepsy and ADHD aged 6 to 17 years enrolled in an ADHD treatment trial, with those reported in the literature on children with ADHD without epilepsy. METHODS: Measures included the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children (KSADS), the Wechsler Abbreviated Scale of Intelligence (WASI), and the Scales for Independent Behavior-Revised (SIB-R). RESULTS: Mean IQ was 86+/-19, and SIB-R Standard Score was 72+/-26. The ADHD-Combined subtype, composed of both inattentive and hyperactive symptoms, was most frequent (58%). Sixty-one percent exhibited a comorbid disorder, including anxiety disorders (36%) and oppositional defiant disorder (31%). CONCLUSIONS: Comorbidity in ADHD with epilepsy is similar to that in ADHD without epilepsy reported in the literature. These preliminary data argue that the pathophysiology of ADHD has common components in both populations.     

Child temperament,ADHD, and caregiver strain: exploring relationships in an epidemiological sample

OBJECTIVE: To investigate the relationship between child-reported dimensions of temperament and attention-deficit/ hyperactivity disorder (ADHD), as well as other indicators of child psychopathology, including disruptive disorders, depression, and anxiety. It also examined whether difficult child temperament scores independently predicted caregiver strain. METHOD: A school-district-wide, two-phase screening design (response rate 70% for phase 2) identified elementary school children at high risk for ADHD. Two hundred high-risk children and their parents completed standardized instruments to assess child temperament, diagnoses of disruptive disorders, children's symptoms of anxiety and depression, and caregiver strain. Relationships were examined using analysis of variance, correlations, and multivariate prediction models, adjusting for child sociodemographic characteristics and psychopathology. All estimates were weighted for sampling design and differential participation. RESULTS: Combined subtype ADHD was associated with lower scores on task orientation and higher scores on general activity level. Depressive symptoms correlated significantly with all but one difficult temperament dimension, in a pattern consistent with clinical symptoms of depression. Child temperament did not vary by ADHD treatment status. Among these high-risk children, maternal caregiver strain experiences were increased by male gender, inattention symptoms, and oppositional defiant disorder, but not by difficult temperament scores. CONCLUSION: This study provides support for Graham and Stevenson's hypothesis of continuity between specific temperament traits and certain child psychiatric disorders, namely ADHD and depressive disorders.     

ADHD and comorbid disorders in relation to family environment and symptom severity

BACKGROUND: To examine the comorbidity of ADHD in association with family environment and the severity of ADHD. METHOD: A screening for ADHD symptoms was conducted among adolescents in the Northern Finland 1986 Birth Cohort (N = 6622). A sample of those adolescents (n = 457), aged 16-18 years, with and without ADHD symptoms was assessed with a diagnostic interview (Kiddie-SADS-PL) and ADHD and comorbid disorders were studied in association with the family characteristics and the number of ADHD symptoms. RESULTS: Adolescents with ADHD had more commonly conduct disorder (P < 0.001), oppositional defiant disorder (P < 0.001), substance abuse (P < 0.001) and mild depression (P < 0.001) than adolescents without ADHD. Adolescents with ADHD and comorbid disorders had more ADHD symptoms (P < 0.001) than those with ADHD alone. Compared to adolescents with ADHD alone those with ADHD and comorbidity lived significantly more commonly in non-intact families, in low-income families, with mothers who were dissatisfied with life and with parents who showed little interest in their adolescents' activities. CONCLUSIONS: Adolescents who develop externalizing disorders comorbid to ADHD seem to suffer from a severe form of ADHD and live in family environments that may not provide sufficient support for optimal development of an adolescent with ADHD.