A family study of psychiatric comorbidity in girls and boys with attention-deficit/hyperactivity disorder.

BACKGROUND: Because attention-deficit/hyperactivity disorder (ADHD) is relatively infrequent among girls, little is known about the nature and causes of psychiatric comorbidity in girls and the reason for gender differences in the prevalence of these comorbidities. METHODS: Using blinded, structured psychiatric interviews, we studied two groups of boys: 140 ADHD probands and 120 non-ADHD comparisons. These groups had 454 and 368 first-degree biological relatives, respectively. We also studied two groups of girls: 140 ADHD probands and 122 non-ADHD comparisons. These groups had 417 and 369 first-degree biological relatives, respectively. RESULTS: The co-occurrence of ADHD and comorbid psychopathology in families was the same for families ascertained through boy and girl probands. CONCLUSIONS: Our results suggest that boys and girls do not differ in the familial risk factors that mediate comorbid psychopathology and the familial aggregation of comorbid disorders in ADHD families. Although this is consistent with prior work suggesting more similarities than differences in the nature of psychiatric comorbidity in ADHD boys and girls, we cannot make strong conclusions, owing to the possibility of cohort effects.     

Revisiting the association between attention-deficit/hyperactivity disorder and anxiety disorders: a familial risk analysis.

BACKGROUND: This study tested competing hypotheses about patterns of familial association between attention-deficit/hyperactivity disorder (ADHD) and anxiety disorders using familial risk analysis methodology. METHODS: The risk for ADHD and anxiety disorders in first-degree relatives was examined after stratifying ADHD probands by the presence or absence of comorbid anxiety disorders. The presence of anxiety disorders in probands and relatives was defined as meeting DSM-III-R diagnostic criteria for > or = 2 anxiety syndromes in the same subject. RESULTS: Familial risk analyses revealed that 1) the risk for anxiety disorders was significantly higher in ADHD probands and their relatives than in control probands and their relatives; 2) the risk for anxiety disorders among the relatives of ADHD probands was limited to those families in which the proband had a diagnosis of ADHD; 3) the risk for anxiety disorders was significantly higher among the relatives of ADHD probands with anxiety disorders than in relatives of ADHD probands without anxiety disorders, but these two groups did not differ in the familial risk for ADHD; and 4) ADHD and anxiety disorders did not cosegregate within families, and there was no evidence for nonrandom (assortative) mating. CONCLUSIONS: These findings are most consistent with the hypothesis that ADHD and anxiety disorders segregate independently in families.     

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.     

Separating attention deficit hyperactivity disorder and learning disabilities in girls: a familial risk analysis

OBJECTIVE: Familial risk analysis was used to clarify the relationship in girls between attention deficit hyperactivity disorder (ADHD) and learning disabilities in either mathematics or reading. METHOD: The authors assessed the presence of ADHD and learning disabilities in 679 first-degree relatives of three groups of index children: girls with ADHD and a comorbid learning disability, girls with ADHD but no learning disabilities, and a comparison group of girls without ADHD. RESULTS: The risk for ADHD was similarly higher in families of ADHD probands with and without learning disabilities; both groups had significantly higher rates of ADHD than did families of the comparison girls. In contrast, only among relatives of ADHD probands with a learning disability was there a higher risk for learning disabilities. A strong (although statistically nonsignificant) difference emerged that suggested at least some degree of cosegregation of ADHD and learning disabilities in family members. There was no evidence of nonrandom mating between spouses with ADHD and learning disabilities. CONCLUSIONS: These results extend previously reported findings regarding the relationship of ADHD and learning disabilities to female subjects and raise the possibility that, in girls, the relationship between ADHD and learning disabilities is due to shared familial risk factors.     

The familial phenotype of obsessive-compulsive disorder in relation to tic disorders: the Hopkins OCD family study.

BACKGROUND: Obsessive-compulsive disorder (OCD) and tic disorders have phenomenological and familial-genetic overlaps. An OCD family study sample that excludes Tourette's syndrome in probands is used to examine whether tic disorders are part of the familial phenotype of OCD. METHODS: Eighty case and 73 control probands and their first-degree relatives were examined by experienced clinicians using the Schedule for Affective Disorders and Schizophrenia-Lifetime Anxiety version. DSM-IV psychiatric diagnoses were ascertained by a best-estimate consensus procedure. The prevalence and severity of tic disorders, age-at-onset of OCD symptoms, and transmission of OCD and tic disorders by characteristics and type of proband (OCD + tic disorder, OCD - tic disorder) were examined in relatives. RESULTS: Case probands and case relatives had a greater lifetime prevalence of tic disorders compared to control subjects. Tic disorders spanning a wide severity range were seen in case relatives; only mild severity was seen in control relatives. Younger age-at-onset of OCD symptoms and possibly male gender in case probands were associated with increased tic disorders in relatives. Although relatives of OCD + tic disorder and OCD - tic disorder probands had similar prevalences of tic disorders, this result is not conclusive. CONCLUSIONS: Tic disorders constitute an alternate expression of the familial OCD phenotype.     

Attention-deficit disorder and conduct disorder in girls: evidence for a familial subtype.

BACKGROUND: The frequent comorbidity between attention-deficit/hyperactivity disorder (ADHD) and conduct disorder (CD) raises the possibility that ADHD+CD is a distinct and separate condition. METHODS: We tested hypotheses about patterns of familial association between ADHD, CD, oppositional defiant disorder (ODD) and adult antisocial personality disorder (ASPD). Using family study methodology in a sample of girls, we found 11 children with diagnoses of ADHD+ CD, 39 with ADHD+ODD, and 90 with ADHD only. These were compared with 122 non-ADHD, non-CD control probands. Familial risk analysis was utilized. RESULTS: Relatives of each ADHD proband subgroup were at significantly greater risk for ADHD, and the relatives of ADHD-only subjects were at a greater risk of ODD than relatives of control subjects. Also, rates of CD were elevated among relatives of ADHD+CD probands only, and the coaggregation of ADHD and the antisocial disorders could not be accounted for by marriages between ADHD and antisocial spouses. Both ADHD and antisocial disorders occurred in the same relatives more often than expected by chance. CONCLUSIONS: These findings suggest that ADHD with and without antisocial disorders may be etiologically distinct disorders and provide evidence for the nosologic validity of ICD-10 hyperkinetic conduct disorder.     

Familial risk analyses of attention deficit hyperactivity disorder and substance use disorders

OBJECTIVE: A robust and bidirectional comorbidity between attention deficit hyperactivity disorder (ADHD) and psychoactive substance use disorder (alcohol or drug abuse or dependence) has been consistently reported in the extant literature. METHOD: First-degree relatives from a large group of pediatrically and psychiatrically referred boys with (112 probands, 385 relatives) and without (105 probands, 358 relatives) ADHD were comprehensively assessed by blind raters with structured diagnostic interviews. Familial risk analysis examined the risks in first-degree relatives for ADHD, psychoactive substance use disorder, alcohol dependence, and drug dependence after stratifying probands by the presence and absence of these disorders. RESULTS: ADHD in the proband was consistently associated with a significant risk for ADHD in relatives. Drug dependence in probands increased the risk for drug dependence in relatives irrespective of ADHD status, whereas alcohol dependence in relatives was predicted only by ADHD probands with comorbid alcohol dependence. In addition, ADHD in the proband predicted drug dependence in relatives, and drug dependence in comparison probands increased the risk for ADHD in relatives. Both alcohol dependence and drug dependence bred true in families without evidence for a common risk between these disorders. CONCLUSIONS: Patterns of familial risk analysis suggest that the association between ADHD and drug dependence is most consistent with the hypothesis of variable expressivity of a common risk between these disorders, whereas the association between ADHD and alcohol dependence is most consistent with the hypothesis of independent transmission of these disorders. Findings also suggest specificity for the transmission of alcohol and drug dependence.     

Adoptive and biological families of children and adolescents with ADHD

OBJECTIVE: Using an adoption study design, the authors addressed the issue of genetics in attention-deficit hyperactivity disorder (ADHD). METHOD: This study examined the rates of ADHD and associated disorders in the first-degree adoptive relatives of 25 adopted probands with ADHD and compared them with those of the first-degree biological relatives of 101 nonadopted probands with ADHD and 50 nonadopted, non-ADHD control probands. RESULTS: Six percent of the adoptive parents of adopted ADHD probands had ADHD compared with 18% of the biological parents of nonadopted ADHD probands and 3% of the biological parents of the control probands. CONCLUSION: Results of this study lend support to the hypothesis that ADHD has a genetic component.     

Validity of DSM-IV subtypes of attention-deficit/hyperactivity disorder: a family study perspective

OBJECTIVE: To test the hypothesis that the clinical severity of subtypes paralleled a gradient of familial severity. METHOD: One hundred forty children with attention-deficit/hyperactivity disorder (ADHD) and 120 normal control children and their biological relatives were studied: Because these data had been collected prior to the publication of DSM-IV, DSM-III-R symptoms were used to approximate DSM-IV subtypes using a method the authors had validated in prior work. RESULTS: The first prediction from the hypothesis was true: rates of ADHD among relatives of each subtype group were greater than rates among relatives of controls. But the second prediction did not hold: rates of ADHD were not significantly higher among relatives of combined-typed probands compared with relatives of other probands. The "gradient model" also predicted that subtypes would not "breed true" (i.e., the subtype of the relative would not be the same as that of the proband). The prediction of nonspecificity was refuted for the inattentive and combined subtypes, but hyperactive-impulsive ADHD was found almost exclusively among relatives of hyperactive-impulsive probands. CONCLUSIONS: Although the results are limited by some small subsamples along with the use of a DSM-III-R-ascertained sample, they provide little evidence for the idea that DSM-IV subtypes of ADHD correspond to familially distinct conditions. They also do not confirm the idea that the subtypes fall along a gradient of familial severity. Instead, they suggest that symptom differences among subtypes are due to nonfamilial, environmental causes.     

Family history of suicidal behavior and mood disorders in probands with mood disorders

OBJECTIVE: First-degree relatives of persons with mood disorder who attempt suicide are at greater risk for mood disorders and attempted or completed suicide. This study examined the shared and distinctive factors associated with familial mood disorders and familial suicidal behavior. METHOD: First-degree relatives' history of DSM-IV-defined mood disorder and suicidal behavior was recorded for 457 mood disorder probands, of whom 81% were inpatients and 62% were female. Probands' lifetime severity of aggression and impulsivity were rated, and probands' reports of childhood physical or sexual abuse, suicide attempts, and age at onset of mood disorder were recorded. Univariate and multivariate analyses were carried out to identify predictors of suicidal acts in first-degree relatives. RESULTS: A total of 23.2% of the probands with mood disorder who had attempted suicide had a first-degree relative with a history of suicidal behavior, compared with 13.2% of the probands with mood disorder who had not attempted suicide (odds ratio=1.99, 95% CI=1.21-3.26). Thirty percent (30.8%) of the first-degree relatives with a diagnosis of mood disorder also manifested suicidal behavior, compared with 6.6% of the first-degree relatives with no mood disorder diagnosis (odds ratio=6.25, 95% CI=3.44-11.35). Probands with and without a history of suicide attempts did not differ in the incidence of mood disorder in first-degree relatives (50.6% versus 48.1%). Rates of reported childhood abuse and severity of lifetime aggression were higher in probands with a family history of suicidal behavior. Earlier age at onset of mood disorder in probands was associated with greater lifetime severity of aggression and higher rates of reported childhood abuse, mood disorder in first-degree relatives, and suicidal behavior in first-degree relatives. CONCLUSIONS: Risk for suicidal behavior in families of probands with mood disorders appears related to early onset of mood disorders, aggressive/impulsive traits, and reported childhood abuse in probands. Studies of such clinical features in at-risk relatives are under way to determine the relative transmission of these clinical features.     

Familial association between attention deficit disorder and anxiety disorders

BACKGROUND AND METHOD: This study tested hypotheses about patterns of familial association between attention deficit disorder (ADD) and anxiety disorders among 356 first-degree relatives of 73 clinically referred children with ADD and 26 normal comparison children. Through structured diagnostic interviews with trained raters, relatives were assessed for adult and childhood psychopathology. After stratifying the sample of ADD probands into those with anxiety disorders and those without, the authors examined patterns of aggregation of ADD and anxiety disorders in the relatives of these probands as well as in the relatives of the normal comparison subjects. RESULTS: Familial risk analyses revealed that 1) familial risk for anxiety disorders was higher among all ADD probands than among the normal subjects; 2) familial risk for ADD was similar in the relatives of the ADD probands and of the probands with ADD and anxiety disorder; 3) the relatives of the ADD probands with and without anxiety disorders were at greater risk for ADD than the relatives of the normal subjects; 4) the risk for anxiety disorders was two times higher in the relatives of the probands who had ADD with anxiety disorder than in those of the ADD probands without anxiety disorders; and 5) there was a tendency for ADD probands' relatives who themselves had ADD to have a higher risk for anxiety disorders than ADD probands' relatives who did not have ADD (cosegregation). CONCLUSIONS: The results were most consistent with the hypotheses indicating that ADD and anxiety disorders segregate independently in families.     

Modern research criteria and the genetics of schizophrenia

The authors assessed the relevance of narrowly defined diagnostic criteria to genetic research in schizophrenia in the nuclear families of 84 chronic schizophrenic probands compared with families of 90 normal control probands. The morbidity risk for narrowly defined schizophrenia in first-degree relatives of patients with the narrow diagnosis was significantly higher than the control rate (3.8% versus 0.3%). The rate of chronic schizophrenia in the relatives of all schizophrenic patients was also significantly higher than the control rate (7.1% versus 0.6%), as was the rate of "spectrum" disorders (33.4% versus 11.3%). The data support the case for familial transmission of narrowly defined schizophrenia.     

Personality disorder in the families of depressed, schizophrenic, and never-ill probands

In a blind family study of 176 probands with nonpsychotic major depression, psychotic major depression, schizophrenia, or no history of DSM-III disorders, only the relatives of depressed probands with mood-incongruent psychotic features had a risk for personality disorders higher than that for the relatives of never-ill probands. The authors did not find a high rate of borderline personality in relatives of depressed probands or of schizotypal personality disorder in relatives of probands with schizophrenia or any psychosis. However, depressed probands with normal dexamethasone test results had a significantly higher familial loading for the DSM-III cluster of histrionic, antisocial, borderline, and narcissistic personality disorders.     

A family study of alcohol dependence: coaggregation of multiple disorders in relatives of alcohol-dependent probands

BACKGROUND: Alcohol dependence tends to aggregate within families. We analyzed data from the family collection of the Collaborative Study on the Genetics of Alcoholism to quantify familial aggregation using several different criterion sets. We also assessed the aggregation of other psychiatric disorders in the same sample to identify areas of possible shared genetic vulnerability. DESIGN: Age-corrected lifetime morbid risk was estimated in adult first-degree relatives of affected probands and control subjects for selected disorders. Diagnostic data were gathered by semistructured interview (the Semi-Structured Assessment for the Genetics of Alcoholism), family history, and medical records. Rates of illness were corrected by validating interview and family history reports against senior clinicians' all sources best estimate diagnoses. Sex, ethnicity, comorbidity, cohort effects, and site of ascertainment were also taken into account. RESULTS: Including data from 8296 relatives of alcoholic probands and 1654 controls, we report lifetime risk rates of 28.8% and 14.4% for DSM-IV alcohol dependence in relatives of probands and controls, respectively; respective rates were 37.0% and 20.5% for the less stringent DSM-III-R alcohol dependence, 20.9% and 9.7% for any DSM-III-R diagnosis of nonalcohol nonnicotine substance dependence, and 8.1% and 5.2% for antisocial personality disorder. Rates of specific substance dependence were markedly increased in relatives of alcohol-dependent probands for cocaine, marijuana, opiates, sedatives, stimulants, and tobacco. Aggregation was also seen for panic disorder, obsessive-compulsive disorder, posttraumatic stress disorder, and major depression. CONCLUSIONS: The risk of alcohol dependence in relatives of probands compared with controls is increased about 2-fold. The aggregation of antisocial personality disorder, drug dependence, anxiety disorders, and mood disorders suggests common mechanisms for these disorders and alcohol dependence within some families. These data suggest new phenotypes for molecular genetic studies and alternative strategies for studying the heterogeneity of alcohol dependence.     

Further evidence for family-genetic risk factors in attention deficit hyperactivity disorder. Patterns of comorbidity in probands and relatives psychiatrically and pediatrically referred samples.

We examined 140 probands with attention deficit hyperactivity disorder, 120 normal controls, and their 822 first-degree relatives using "blind" raters and structured diagnostic interviews. Compared with controls, probands with attention deficit hyperactivity disorder were more likely to have conduct, mood, and anxiety disorders. Compared with relatives of controls, relatives of probands with attention deficit hyperactivity disorder had a higher risk for attention deficit hyperactivity disorder, antisocial disorders, major depressive disorder, substance dependence, and anxiety disorders. Patterns of comorbidity indicate that attention deficit hyperactivity disorder and major depressive disorders may share common familial vulnerabilities, that attention deficit hyperactivity disorder plus conduct disorder may be a distinct subtype, and that attention deficit hyperactivity disorder and anxiety disorders are transmitted independently in families. These results extend previous findings indicating family-genetic influences in attention deficit hyperactivity disorder by using both pediatrically and psychiatrically referred proband samples. The distributions of comorbid illnesses in families provide further validation for subgrouping probands with attention deficit hyperactivity disorder by comorbidity.     

A family history study of binge-eating disorder

Family studies of anorexia nervosa and bulimia nervosa have yielded important information about the etiologies of these eating disorders. By contrast, little is known about familial factors of etiologic importance for binge-eating disorder (BED). The purpose of the current family history study was to assess the prevalence of comorbid psychopathology in a non-treatment seeking female sample of 31 probands with BED, 32 control probands without BED, and their 283 first-degree relatives. In-person semistructured clinical interviews were conducted with the probands, who also served as informants for all of their first-degree relatives. Significantly higher lifetime rates of major depressive disorder, dysthymic disorder, and social phobia were found among women with BED compared with control women. Significantly higher lifetime rates of bipolar (I or II) disorder, any depressive disorder, nearly all anxiety disorders, anorexia nervosa, and BED were reported among the first-degree relatives of women with BED compared with the first-degree relatives of control women. Furthermore, female relatives of women with BED were reported to have higher rates of substance use disorders and dysthymic disorder compared with female relatives of control women without BED. Nearly all disorders that were elevated in relatives of women with BED followed a pattern of independent transmission from BED. The primary exception was substance use disorder among female relatives, whose transmission pattern was consistent with that of a shared etiology with BED. Thus, BED and substance use disorder may share a common mechanism of familial transmission among women.     

The relationship between syndromes of the psychotic illness and familial liability to schizophrenia and major mood disorders

BACKGROUND: Previous studies examining the relationship between psychopathological syndromes of the psychotic illness and familial liability to schizophrenia and mood disorders have obtained inconclusive results. The aim of this study is to further examine this issue by analyzing a large sample of psychotic probands and their first-degree relatives. METHODS: The sample was composed of 660 psychotic inpatients and their 2987 first-degree relatives. Probands were assessed for index episode and lifetime symptoms, while relatives were assessed for lifetime diagnosis of schizophrenia and major mood disorders. Associations between factor-analysis derived syndromes in probands and familial loading for schizophrenia and major mood disorders were tested. RESULTS: Familial morbid risk of schizophrenia was predicted by the negative syndrome in probands and familial morbid risk of mood disorders was predicted by mania, depression and catatonia syndromes in probands. This association pattern was relatively independent of type of symptom rating (index episode or lifetime) and probands' diagnosis of schizophrenia or major mood disorder. Familial loading for schizophrenia and mood disorders cut-across the DSM-IV categories of psychotic disorders in probands. CONCLUSION: From a dimensional perspective, the negative syndrome is related to familial liability to develop schizophrenia. Mania, depression and catatonia syndromes are related to the familial liability to develop major mood disorders. Categories of psychotic disorders are on a continuum of familial liability to schizophrenia and major mood disorders.     

Morbidity risk for obsessive-compulsive spectrum disorders in first-degree relatives of patients with eating disorders

OBJECTIVE: A hypothesis that eating disorders are a phenomenological variant of obsessive-compulsive disorder (OCD) has been proposed. This study was conducted to determine whether anorexia nervosa and bulimia, the two main eating disorders, are familial and whether the risk for obsessive-compulsive spectrum disorders (OCD and tic disorders) is higher in families of patients with eating disorders. METHOD: The morbidity risk for obsessive-compulsive spectrum disorders in first-degree relatives of 136 female probands with eating disorders (84 with anorexia nervosa, 52 with bulimia) was compared to that for first-degree relatives of 72 female comparison subjects. RESULTS: The morbidity risk for obsessive-compulsive spectrum disorders was significantly higher among the 436 relatives of the eating disorder probands than among the 358 relatives of the comparison subjects (9.69% versus 0%). This finding was independent of any comorbid diagnosis of an obsessive-compulsive spectrum disorder in the eating disorder probands. The eating disorder group and the comparison group did not differ in familial risk for eating disorders and tic disorders. CONCLUSIONS: To better understand the genetic components of eating disorders, these disorders should be considered as part of the obsessive-compulsive spectrum of disorders.     

Psychiatric disorders in relatives of probands with opiate addiction

Previous research has documented high rates of major depression and antisocial personality in opiate addicts. This study was designed to investigate the relationship of dual diagnosis in opiate-addicted probands to family history of psychiatric disorders and substance use disorders in biological relatives. Psychiatric disorders and substance use disorders were evaluated using direct interview and family history in a sample of 877 first-degree relatives of 201 opiate addicts and 360 relatives of 82 normal controls. Results indicate that (1) compared with relatives of normal subjects, opiate addicts' relatives had substantially higher rates of alcoholism, drug abuse, depression, and antisocial personality; (2) relatives of depressed opiate-addicted probands had elevated rates of major depression and anxiety disorders but not of other disorders, suggesting the validity of subtyping opiate addicts by the presence or absence of major depression; and (3) in contrast, relatives of antisocial opiate addicts had rates of disorders that were not significantly different from those of relatives of opiate addicts without antisocial personality. Implications of these findings for the classification and treatment of substance abuse are discussed.