Environmental factors in offspring of parents with mood disorders and their role in parent-child transmission: findings from a 14-year prospective high-risk study

Background

The factors involved in the transmission of mood disorders are only partially elucidated. Aside from genes, the family environment might play a crucial role in parent–child transmission. Our goals were to (1) assess the associations of parental bipolar disorder (BPD) and Major Depressive Disorder (MDD) with individual or shared family environmental factors, including traumatic events in offspring, parental separation, family cohesion and parental attitudes; and 2) test whether these factors were mediators of the association between exposure to parental mood disorders and the onset of these disorders in offspring.

Methods

The sample stems from an ongoing family high-risk study of mood disorders conducted in the French-speaking part of Switzerland. Given the strong impact of the age of onset of parental disorders on their transmission to children, parental disorders were dichotomized according to the onset (cut-off 21 years). Probands with early-onset (n = 30) and later-onset BPD (n = 51), early-onset (n = 21) and later-onset MDD (n = 47) and controls (n = 65), along with their spouses (n = 193) and offspring (n = 388; < 18 years on study inclusion), were assessed over a mean follow-up duration of 14 years (s.d: 4.6). The environmental measures were based on reports by offspring collected before the onset of their first mood episode.

Results

Offspring of probands with later-onset BPD and offspring of probands with both early-onset and later-onset MDD reported traumatic events more frequently than comparison offspring, whereas exposure to parental separation was more frequent in all groups of high-risk offspring. Moreover, several familial environment scores including parenting attitudes differed between offspring of probands with BPD and comparison offspring. However, none of these factors were mediators of the parent–child transmission of BPD. Among the environmental factors, traumatic events were shown to be modest mediators of the transmission of early-onset MDD.

Conclusions

Our data do not support the implication of the assessed environmental factors in the parent–child transmission of BPD. In contrast to BPD, traumatic events partially mediate the parent–child transmission of early-onset MDD, which has important implications for intervention and prevention. Early therapeutic efforts in offspring exposed to these events are likely to reduce their deleterious impact on the risk of subsequent MDD.

Análisis factorial de las escalas FACES (Family Adaptability and Cohesion Evaluation Scales) con familias en situación de riesgo psicosocial

En este artículo se presenta un análisis factorial de las escalas FACES III con una muestra de familias en situación de riesgo psicosocial (N = 324). Los resultados no replican la estructura bidimensional original de la prueba, e indican que solo la escala de cohesión (prescindiendo de tres ítems) obtiene propiedades psicométricas aceptables en esta muestra. Las significativas relaciones de las puntuaciones de esta escala con las de otras dimensiones relevantes del microsistema familiar ofrecen algunas evidencias de la validez de esta solución. Se discute la necesidad de revisar la escala de adaptabilidad propuesta por los autores y reformularla para poder evaluar empíricamente este constructo formulado teóricamente desde el modelo circumplejo del funcionamiento familiar.