Anxiety and major depression comorbidity in a family study of obsessive-compulsive disorder

To understand the familial relationship between obsessive-compulsive disorder (OCD), other anxiety disorders, and major depressive disorder (MDD), we examined the rates of anxiety disorders and MDD in first-degree relatives of OCD probands and controls, the association between age at onset of OCD and the occurrence of other anxiety disorders and major depressive disorder in relatives of probands, and the co-transmission of specific anxiety disorders, MDD, and OCD within families of probands. Recurrence risks were estimated from 466 first-degree relatives of 100 probands with OCD and 113 first-degree relatives of 33 non-psychiatric controls. Rates of non-OCD anxiety disorders and MDD were comparable in relatives of OCD probands and controls. Rates of anxiety disorders and MDD were higher among case relatives with OCD than among case relatives without OCD and control relatives. Fifty percent of case relatives with OCD had at least one comorbid anxiety disorder. Early age at onset (<10 years) in probands was associated with higher rates of anxiety and depression comorbidity among case relatives with OCD but not among case relatives without OCD. The occurrence of specific anxiety disorders and MDD in case relatives was independent of the same comorbid diagnosis in the OCD probands. OCD, panic disorder, generalized anxiety disorder, and MDD occurred together more often than expected by chance among individuals with OCD. Furthermore, age at onset in probands is associated with specific anxiety and affective comorbidity among case relatives. These findings support the hypothesis that early- and late-onset OCD represent different etiologic variants.     

Comorbidity of attention deficit hyperactivity disorder with conduct, depressive, anxiety, and other disorders

OBJECTIVE: Attention deficit hyperactivity disorder is a heterogeneous disorder of unknown etiology. Little is known about the comorbidity of this disorder with disorders other than conduct. Therefore, the authors made a systematic search of the psychiatric and psychological literature for empirical studies dealing with the comorbidity of attention deficit hyperactivity disorder with other disorders. DATA COLLECTION: The search terms included hyperactivity, hyperkinesis, attention deficit disorder, and attention deficit hyperactivity disorder, cross-referenced with antisocial disorder (aggression, conduct disorder, antisocial disorder), depression (depression, mania, depressive disorder, bipolar), anxiety (anxiety disorder, anxiety), learning problems (learning, learning disability, academic achievement), substance abuse (alcoholism, drug abuse), mental retardation, and Tourette's disorder. FINDINGS: The literature supports considerable comorbidity of attention deficit hyperactivity disorder with conduct disorder, oppositional defiant disorder, mood disorders, anxiety disorders, learning disabilities, and other disorders, such as mental retardation, Tourette's syndrome, and borderline personality disorder. CONCLUSIONS: Subgroups of children with attention deficit hyperactivity disorder might be delineated on the basis of the disorder's comorbidity with other disorders. These subgroups may have differing risk factors, clinical courses, and pharmacological responses. Thus, their proper identification may lead to refinements in preventive and treatment strategies. Investigation of these issues should help to clarify the etiology, course, and outcome of attention deficit hyperactivity disorder.     

A controlled family history study of prepubertal major depressive disorder

First-degree (N = 195) and second-degree (N = 785) adult relatives of prepubertal children with major depression (N = 48), children with nonaffective psychiatric disorders (N = 20), and normal children (N = 27) were assessed by the Family History-Research Diagnostic Criteria method (FH-RDC), except for the adult informant (usually the mother), who was directly interviewed. Compared with normal controls, prepubertal children with major depressive disorder (MDD) had significantly higher familial rates of psychiatric disorders in both first- and second-degree relatives, especially MDD, alcoholism, and "other" (mostly anxiety) diagnoses. Relatives of children in the nonaffective psychiatric control (PC) group had low rates of alcoholism, high rates of other (anxiety) disorder diagnoses, and intermediate rates of MDD (accounted for by those children with separation anxiety). This suggests that prepubertal onset of major depression may be especially likely in families with a high aggregation of affective disorders when these families also have a high prevalence of alcoholism, and that a proportion of children without affective disorder but with separation anxiety disorder in this study were at high risk for the development of affective illness later in life. These results support the validity of prepubertal-onset depressive illness as a diagnostic category, and are consistent with high familial rates of MDD and other psychiatric disorders found in family studies of adolescent and early-onset adult probands with major affective disorders, and with studies of the offspring of parents with major affective disorders. Within the child MDD group substantial heterogeneity was found. Low familial rates of MDD were associated with suicidality and comorbid conduct disorder in the child probands. The highest familial rates of MDD, approximately threefold those in the normal controls, and all the bipolar relatives, were found in the families of prepubertal probands with MDD who never had a concrete suicidal plan or act and who were without comorbid conduct disorder. A useful nosological continuum in which to classify prepubertal MDD may be to place at one end those patients with comorbid conduct disorder and at the other end those patients with manifestations related to bipolarity, including hypomania, mania, and psychotic subtype.     

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.     

Gilles de la Tourette's syndrome and attention deficit disorder with hyperactivity. Evidence against a genetic relationship

Results of a family study of Gilles de la Tourette's syndrome (TS) suggest that TS and attention deficit disorder (ADD) with hyperactivity are genetically separate disorders transmitted independently in families at risk. Although the rate of TS among the relatives of the two proband groups was virtually the same (10.3% vs 11.1%), the rate of ADD among the relatives of probands with TS and ADD with hyperactivity was approximately eight times higher than the rate of ADD among the relatives of the probands with TS only. In those families where the proband had both TS and ADD, the two traits segregated independently. Therefore, there is no evidence to suggest that the two disorders are genetically related.     

Comorbidity of internalizing disorders in children with oppositional defiant disorder

Oppositional defiant disorder (ODD) is often comorbid with other psychiatric disorders in childhood. Its association with attention deficit hyperactivity disorder and conduct disorder has been well studied. Recent studies suggest that children with ODD have substantial comorbidity with anxiety and depressive (internalizing) disorders, as well. Identifying the pattern of internalizing comorbidity with ODD in childhood and adolescence and how this varies across age and gender may help to identify mechanisms of such comorbidity. This systematic review presents evidence on the association of internalizing disorders with ODD across childhood and adolescence. Data from cross-sectional and longitudinal studies in clinic, community and epidemiologic samples are considered separately. Findings suggest that while internalizing comorbidity with ODD is present at all ages, the degree of comorbidity may vary over time in particular groups of children. Girls and boys appear to have different patterns of ODD comorbidity with either anxiety or depression, as well as ages of onset of ODD, however more large studies are required. Children with ODD in early life require further study as they may be a subgroup at increased risk for anxiety and affective disorders. This could have important implications for the treatment of these ODD children and the prevention of sequential comorbidity.     

Sustained attention-deficit confirmed in euthymic bipolar disorder but not in first-degree relatives of bipolar patients or euthymic unipolar depression.

BACKGROUND: Cognitive dysfunction persists in the euthymic phase of bipolar disorder and may provide a marker of underlying neuropathology and disease vulnerability. This study aimed to replicate a deficit in sustained attention in euthymic bipolar patients and investigate sustained attention in first-degree relatives of bipolar probands and in remitted patients with major depressive disorder. METHODS: The rapid visual information processing (RVIP) task was used to measure sustained attention in 15 euthymic patients with bipolar disorder and 15 control subjects in experiment 1 and in 27 first-degree relatives of bipolar probands, 15 remitted patients with major depressive disorder, and 46 control subjects in experiment 2. RESULTS: Sustained attention deficit was confirmed in the euthymic bipolar patients in experiment 1, but the deficit was not statistically significant in remitted major depressed patients or in the relatives of bipolar probands. CONCLUSIONS: A deficit of sustained attention is not present in patients with recurrent major depression tested during remission nor is it discriminable in the first-degree relatives of bipolar probands. Thus, the confirmed abnormality in euthymic bipolar patients may be acquired as a consequence of bipolar illness. However, future studies of relatives will require larger sample sizes to exclude or utilize small genetic effects.     

Evidence of familial association between attention deficit disorder and major affective disorders

With the use of family study methods and assessments by "blinded" raters, we tested hypotheses about patterns of familial association between DSM-III attention deficit disorder (ADD) and affective disorders (AFFs) among first-degree relatives of clinically referred children and adolescents with ADD (73 probands, 264 relatives) and normal controls (26 probands, 92 relatives). Among the 73 ADD probands, 24 (33%) met criteria for AFFs (major depression, n = 15 [21%]; bipolar disorder, n = 8 [11%]; and dysthymia, n = 1 [1%]). After stratification of the ADD sample into those with AFFs (ADD + AFF) and those without AFF (ADD), familial risk analyses revealed the following: (1) the relatives of each ADD proband subgroup were at significantly greater risk for ADD than were relatives of normal controls; (2) the age-corrected morbidity risk for ADD was not significantly different between relatives of ADD and ADD + AFF (27% vs 22%); however, these two risks were significantly greater than the risk to relatives of normal controls (5%); (3) the risk for any AFF (bipolar disorder, major depressive disorder, or dysthymia) was not significantly different between relatives of ADD probands and ADD + AFF probands (28% and 25%), but these two risks were significantly greater than the risk to relatives of normal controls (4%); (4) ADD and AFFs did not cosegregate within families; and (5) there was no evidence for nonrandom mating. These findings are consistent with the hypothesis that ADD and AFFs may share common familial vulnerabilities.     

Psychopathology risk transmission in children of parents with substance use disorders

OBJECTIVE: Children of fathers with substance use disorders are at increased risk for psychopathology, including conduct disorder, attention deficit hyperactivity disorder (ADHD), major depressive disorder, and anxiety disorders. This study examined the distinct influences of parent substance use disorder and other psychopathology in the transmission of the risk for psychopathology to their children. METHOD: The subjects were 1,167 children (ages 6-14 years; 62% were male, 38% were female) from 613 families recruited according to a high-risk paradigm. Of these families, 294 had fathers with a substance use disorder (high-risk group), and 319 had fathers without a substance use disorder or other mental disorder (low-risk group). In all families, father, mother, and children were directly assessed. Mixed-effects ordinal regression analyses controlled for the nested data structure. RESULTS: For conduct disorder, ADHD, major depression, and anxiety disorders, the results indicated that the predominant predictor of specific mental disorders in offspring was a history of the corresponding disorders in both parents. CONCLUSIONS: These results support specific parent-child transmission for childhood psychopathology.     

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.     

Using family studies to understand comorbidity

Summary Methods for investigating the nature of comorbidity of two psychiatric disorders, where each disorder is known to be familial, using family studies are described. The methods consist of using a study design which include relatives of four proband groups, namely probands with the pure form of each disorder, probands with the comorbid form of the disorders, and control probands who have neither of the disorders. Disorders in relatives were classified to parallel the disorder categories in probands. Patterns of transmission of these disorders between probands and relatives hypothesized under various models of comorbidity, and statistical methods for formally testing these hypothesis are described. These methods are illustrated, by applying them to data from a recent family study to investigate the relationship and the cause of comorbidity between panic disorder and major depressive disorder.     

Comorbidity in the interpretation of dexamethasone suppression test results in children: a review and report

The dexamethasone suppression test (DST) was administered as part of the initial clinical assessment to 83 children and adolescents who were consecutively referred for outpatient evaluation. All diagnoses were made clinically by a child psychiatrist according to DSM-III criteria. A weight-corrected dose of dexamethasone of 17 micrograms/kg was used. DSM-III diagnoses were made independent of DST results. Patients were stratified into four main diagnostic groups: major depressive disorder (MDD) (N = 27); attention deficit disorder with hyperactivity (ADDH) (N = 22); major depressive disorder plus attention deficit disorder with hyperactivity (MDD + ADDH) (N = 29); and psychiatric controls (PC) (N = 5). Rates of dexamethasone nonsuppression were found to be similarly elevated in children with MDD (29.6%), ADDH (22.7%), and MDD + ADDH (37.9%). All 5 psychiatric control patients had a normal postdexamethasone suppression (0%). A similar pattern of results emerged in a reexamination of the literature on available studies of DST in juveniles which revealed that children with major affective disorders, attention deficit disorder (ADDH), and anxiety disorders had comparable DST results that were significantly higher than the 5.6% rate found in normal controls. These findings provide further support for similarities in DST results between ADDH and MDD in outpatients. Although these results suggest a lack of specificity of the DST as a laboratory aid for the diagnosis of juvenile affective disorders, they are also consistent with findings indicating that the DST may be an index of clinical severity and other findings suggesting a possible association between ADDH and MDD. Despite its limitations, the DST may provide potentially useful clinical and research information regarding the pathophysiology of psychiatric disorders and in alerting clinicians to the presence of serious psychiatric disorders. The findings also stress the relevance of assessing comorbidity in interpreting DST results.     

Chernobyl exposure as stressor during pregnancy and behaviour in adolescent offspring

Objective: Research in animals has shown that exposure to stressors during pregnancy is associated with offspring behavioural disorders. We aimed to study the effect of in utero exposure to the Chernobyl disaster in 1986, and maternal anxiety presumably associated with that exposure, on behaviour disorder observed at age 14. Method: Exposed (n = 232) and non‐exposed Finnish twins (n = 572) were compared. A semi‐structured interview was used to assess lifetime symptoms of depression, generalized anxiety disorder, attention deficit hyperactivity disorder, conduct disorder and oppositional defiant disorder symptoms. Results: Adolescents who were exposed from the second trimester in pregnancy onwards, had a 2.32‐fold risk (95% CI: 1.13–4.72) of having lifetime depression symptoms, an increased risk of fulfilling DSM‐III‐R criteria of a major depressive disorder (OR = 2.48, 95% CI: 1.06–5.7), and a 2.01‐fold risk (95% CI: 1.14–3.52) of having attention deficit hyperactivity disorder symptoms. Conclusion: Perturbations in fetal brain development during the second trimester may be associated with the increased prevalence of depressive and attention deficit hyperactivity disorder symptoms.     

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.     

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.     

High rate of affective disorders in probands with attention deficit disorder and in their relatives: a controlled family study

In a controlled family study of attention deficit disorder, data were collected on first-degree relatives of 22 children with attention deficit disorder and 20 normal children. The rate of major affective disorder was significantly higher in the attention deficit disorder probands (32%) and their relatives (27%) than in the normal control subjects (0%) and their relatives (6%). The findings indicate that attention deficit disorder is associated with higher risk for affective disorder and suggest that probands who have both disorders may represent a distinct subgroup.     

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.     

Family study of affective spectrum disorder

BACKGROUND: Affective spectrum disorder (ASD) represents a group of psychiatric and medical conditions, each known to respond to several chemical families of antidepressant medications and hence possibly linked by common heritable abnormalities. Forms of ASD include major depressive disorder (MDD), attention-deficit/hyperactivity disorder, bulimia nervosa, cataplexy, dysthymic disorder, fibromyalgia, generalized anxiety disorder, irritable bowel syndrome, migraine, obsessive-compulsive disorder, panic disorder, posttraumatic stress disorder, premenstrual dysphoric disorder, and social phobia. Two predictions of the ASD hypothesis were tested: that ASD, taken as a single entity, would aggregate in families and that MDD would coaggregate with other forms of ASD in families. METHODS: Probands with and without MDD, together with their first-degree relatives, were interviewed using the Structured Clinical Interview for DSM-IV and a supplemental interview for other forms of ASD. The familial aggregation and coaggregation of disorders were analyzed using proband predictive logistic regression models, including a novel bivariate model for the presence or absence of each of 2 disorders in a relative as predicted by the presence or absence of each of 2 disorders in the associated proband. RESULTS: In the 178 interviewed relatives of 64 probands with MDD and 152 relatives of 58 probands without MDD, the estimated odds ratio (95% confidence interval) for the familial aggregation of ASD as a whole was 2.5 (1.4-4.3; P =.001) and for the familial coaggregation of MDD with at least one other form of ASD was 1.9 (1.1-3.2; P =.02). CONCLUSIONS: Affective spectrum disorder aggregates strongly in families, and MDD displays a significant familial coaggregation with other forms of ASD, taken collectively. These results suggest that forms of ASD may share heritable pathophysiologic features.     

Hyperactive boys almost grown up. I. Psychiatric status

We report a prospective longitudinal study of 101 male adolescents (ages 16 to 23 years) who had been diagnosed hyperactive in childhood (ages 6 to 12 years), compared with 100 normal controls. The DSM-III diagnoses were made blind to group membership. Information was obtained for 98% of the original cohort. The full attention deficit disorder with hyperactivity (ADDH) syndrome persisted in 31% of the probands vs in 3% of the controls. The only other two conditions that distinguished the groups significantly were conduct and substance use disorders. These disorders aggregated significantly among the probands with continued ADDH. The results indicate that the greatest risk factor for the development of antisocial behavior and drug abuse is the maintenance of ADDH symptoms. Substance use disorders followed the onset of conduct disorder in the overwhelming majority of the cases.     

Family study of girls with attention deficit hyperactivity disorder

OBJECTIVE: Because attention deficit hyperactivity disorder (ADHD) is relatively infrequent among girls, little is known about the causes of ADHD in girls. To help fill this gap in the literature, the authors assessed the familial transmission of ADHD in families ascertained through girls.METHOD: Interviewers who were blind to diagnosis administered structured psychiatric interviews to 140 girls with ADHD and their 417 first-degree relatives and to 122 girls without ADHD and their 369 first-degree relatives.RESULTS: The relatives of the ADHD girls had a significantly higher prevalence of ADHD, according to either the DSM-III-R or DSM-IV definition, than the relatives of the comparison girls. However, this did not differ from the prevalence the authors reported previously for families of boys with ADHD. Like the boys' families, the relatives of the girl probands also had significantly higher prevalences of antisocial, mood, anxiety, and substance use disorders, although the prevalence of familial antisocial disorders was lower than had been observed in the boys' families. There was no association between the DSM-IV subtypes of the probands and relatives.CONCLUSIONS: The familial transmission of ADHD and comorbid disorders generalizes to families of girls with ADHD. Neither proband gender nor subtype influences the familial transmission of ADHD.