[Psychopathology across three family generations: an epidemiological study in Mexico City]

To estimate the risk of psychiatric disorders across three family generations.

The research design corresponds to a "family history study" and is based upon a household survey conducted in 1995, on a representative sample of Mexico City's adult population aged 18 - 65 years (n=1932). Briefly, a standardized assessment of adults' lifetime prevalence of psychiatric disorders was obtained using an amended version of the Composite International Diagnostic Interview, CIDI. In addition, all respondents provided information on their parents' psychiatric history of anxiety, affective disorders, and substance-use disorders.Also, respondents who had 4-16 year old children living in the same household were interviewed using a standardized questionnaire that included specific questions on their children's psychiatric symptoms (n=925 parents, corresponding to 1686 children and adolescents). Familial psychopathology across generations was defined as follows: a) history of psychiatric disorders only in grandparents; b) history of psychiatric disorders in one parent only (mother or father); and, c) history of psychiatric disorders history in grandparents and in parent. The risk of psychiatric morbidity was estimated via odds ratios obtained from logistic regression models with and without random-effects and using Generalized Estimation Equations with robust variance estimation.

The risk for psychopathology in the offspring across generations was estimated to be two to three times higher when psychiatric disorders occurred among the parents. The risk of psychiatric disorders was estimated to be higher when comorbidity among different types of disorders was present. Conclusions. The results suggest that the risk for developing psychopathology across generations is at least moderate and relatively stable. Familial transmission of psychopathology across three generations seems to resemble a genetic mixed model.