• 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.

https://jamanetwork.com/HttpHandlers/ArticlePdfHandler.ashx?journal=PSYCH&articleId=494545&pdfFileName=archpsyc_46_5_005.pdf

A Controlled Family History Study of Prepubertal Major Depressive Disorder

A genetic factor in affective disorders is suggested by twin and family history studies. The form of disorder (BP or UP) is transmitted within families. Early onset of affective disorder is associated with increased morbid risk of the disorder in relatives, but age at onset is not itself a transmitted factor. Female relatives have higher prevalence of illness, but sex of the ill person does not appear to be a factor in transmission. Genetic models of multifactorial or single-gene autosomal inheritance are compatible with some but not all of the family history studies reported. The hypothesis of sex-linked transmission of BP illness has been proposed, and some pedigrees compatible with X-linkage have been reported, but family studies do not suggest that this is generally present. Other possible modes of inheritance remain to be tested. Investigative strategies for identification of the “affective genotype” are discussed on the basis of biochemical, pharmacological, or other characteristics of persons with the disorders and their relatives, and on the basis of studies of known linkage markers.

The inheritance of affective disorders: a review of data and of hypotheses.

The mediating role of emotions in alcohol use.

Context If family history is associated with clinical features that are thought to index seriousness of disorder, this could inform clinicians predicting patients' prognosis and researchers selecting cases for genetic studies. Although tests of associations between family history and clinical features are numerous for depression, such tests are relatively lacking for other disorders. Objective To test the hypothesis that family history is associated with 4 clinical indexes of disorder (recurrence, impairment, service use, and age at onset) in relation to 4 psychiatric disorders (major depressive episode, anxiety disorder, alcohol dependence, and drug dependence). Design Prospective longitudinal cohort study. Setting New Zealand. Participants A total of 981 members of the 1972 to 1973 Dunedin Study birth cohort (96% retention). Main Outcome Measures For each disorder, family history scores were calculated as the proportion of affected family members from data on 3 generations of the participants' families. Data collected prospectively at the study's repeated assessments (ages 11-32 years) were used to assess recurrence, impairment, and age at onset; data collected by means of a life history calendar at age 32 years were used to assess service use. Results Family history was associated with the presence of all 4 disorder types. In addition, family history was associated with a more recurrent course for all 4 disorders (but not significantly for women with depression), worse impairment, and greater service use. Family history was not associated with younger age at onset for any disorder. Conclusions Associations between family history of a disorder and clinical features of that disorder in probands showed consistent direction of effects across depression, anxiety disorder, alcohol dependence, and drug dependence. For these disorder types, family history is useful for determining patients' clinical prognosis and for selecting cases for genetic studies.

https://jamanetwork.com/journals/jamapsychiatry/articlepdf/483128/yoa90004_738_747.pdf

Predictive value of family history on severity of illness: the case for depression, anxiety, alcohol dependence, and drug dependence.

Early age-of-onset appears to predict higher familial loading in bipolar affective disorder. This finding, coupled with ongoing attention to the importance of genomic heterogeneity for segregation and linkage analyses, underscores the value of research on juvenile samples. This research is reviewed, and implications for future research on genetic classification of bipolar illness are noted.

Cadoret Rj

Papers

Unipolar depression: a family history study.