Female interpersonal dependency: genetic and environmental components and its relationship to depression as a function of age.

OBJECTIVES: Research has shown that female interpersonal dependency is significantly associated with clinical depression but is only marginally related to childhood environmental factors. This study replicates the finding of O'Neill and Kendler that such dependency has a significant genetic component and no shared environmental component and extends this by examining the effect of age and the relationship between interpersonal dependency and depression. METHOD: A genetic model analysis for female twin pairs was made incorporating a scale from the Interpersonal Dependency Inventory, and the association between dependency quartiles and depression for both sexes determined. Dependency data were obtained by questionnaire from 4427 monozygotic and dizygotic twins, 90% female and this was combined with lifetime incidence of depression data in three categories of severity. RESULTS: Additive genetic variance components of 49% and 41% were estimated for those females between 19-64 and 65-87 years, respectively, with no significant effect for the shared family environment for either age group. Only female dependency was found to be associated with the incidence of depression. Incidence levels of severe depression for older females in the highest quartile of dependency were 26% compared to 43% for the younger females. CONCLUSION: The investigation has estimated that nearly half of the variance in female interpersonal dependency is genetic in origin. It has also confirmed that high levels of such dependency are associated with the incidence of severe depression and this effect reduces with age. The possible reasons for this age-related effect are discussed.

Long-term effects of the British evacuation of children during World War 2 on their adult mental health.

OBJECTIVES: This study of 870 respondents aged 62-72 years investigates possible long-term effects on adult mental health due to temporary childhood separation by evacuation in the United Kingdom during World War 2. METHOD: Using univariate and multivariate analyses associations were examined between upbringing, evacuation experience and certain life-course variables with the lifetime incidence of depression and clinical anxiety, and also with the dependency and self-critical factors of the Depressive Experiences Questionnaire (DEQ) (Blatt, S.J., D'Affitti, J.P., & Quinlan, D.M. (1976). Experiences of depression in normal young adults. Journal of Abnormal Psychology, 85, 383-389.) were examined by univariate and multivariate analyses. RESULTS: Those evacuated at a young age, 4-6 years, or who received poor foster care, were found to be at a greater risk of depression and clinical anxiety, with high levels of self-criticism. Compared to other groups respondents evacuated at 13-15 years age, who received good care, had reduced incidences of both affective disorders, comparable to those who were not evacuated. The quality of home nurture was also found to be significantly associated with both disorders. Structural equation models for each sex based on those variables significantly associated with depression explained 45% of the variance of the incidence of depression for males and 25% for females. The models also confirmed the relatively high levels of dependency for females and their vulnerability to these levels in terms of depression. CONCLUSION: The study demonstrated significant associations between childhood experiences and lifespan mental health, reinforcing the importance of knowledge of childhood history in the clinical treatment of older adults.

Genetic and environmental components of female depression as a function of the severity of the disorder.

BACKGROUND: Both clinical care and genome-wide studies need to account for levels of severity in the etiology of depression. The purpose of the study is to estimate the genetic and environmental components of female depression as a function of the severity of the disorder. METHODS: A genetic and environmental model analysis of depression incidence was made using the IOP Depression Severity Measure (IDSM). Details of lifetime depression incidence were obtained by questionnaire from twins on the DTR registry. Data from 1449 matched female twin pairs in the age range 19-85 years in four ordinal categories of increasing severity were employed in the analysis. RESULTS: Estimates of additive and dominance genetic components of 27% and 25% were found when all three levels of depression were included, and near zero and 33% when the recurrent/severe level was excluded. Shared environmental effects were not significant in either case, but the estimate for random environmental effects was greater when the severe level was excluded. CONCLUSIONS: These results suggest that the incidence of severe depression is associated with homozygotic alleles and the less severe with heterozygotic alleles. This is in accord with the finding that the hereditary component of severe depression is relatively high and that milder forms are more dependent on life-time environmental factors. Such conclusions have clinical implications for the diagnosis and treatment of the disorder by practicing psychiatrists. They also lead to the importance of focusing future genome-wide and linkage studies on those females with severe levels of depression if progress in identifying genetic risk loci is to be made.

Effect of childhood age in foster care on the incidence of divorce in adulthood.

This retrospective study examines the long-term effect of the age at which British children were fostered in World War II on their divorce rate. A total of 859 respondents, aged 62 to 72 years, were recruited who had childhood homes in the county of Kent in southeast England during the war. Of these, 770 had been evacuated and fostered, and the remainder stayed at home. Reflecting the wartime concerns of Bowlby, Miller, and Winnicott (1939) regarding the wisdom of separating young children from their parents for a potentially long period, male and female respondents evacuated between the ages of 4 to 6 years had a significantly higher incidence of divorce compared with those in the 13- to 15-year age group. This association was found to be mediated by attachment style in which the fearful category was predominant. The relevance of these results in the broader developmental context, and to family counseling, are briefly discussed.

Childhood temporary separation: long-term effects of the British evacuation of children during World War 2 on older adults' attachment styles.

This study investigates long-term effects on adult attachment due to temporary childhood separation as a result of the British evacuation of children during World War 2. A total of 859 respondents, aged 62-72 years, were recruited who had childhood homes in the county of Kent during the war. Of these, 770 had been evacuated and 89 remained at home and formed a non-evacuated control group. They participated in this retrospective survey of possible associations between childhood experiences of the evacuation, early upbringing, and later life-course variables, with adult attachment style assessed by the Relationship Questionnaire (Bartholomew & Horowitz, 1991). Reflecting the wartime concerns of Bowlby, male and female respondents evacuated between the ages of 4 and 6 years showed low incidences in secure attachment style of 38% and 27%, compared to those not evacuated at 64% and 44%, respectively, with a corresponding increase in the fearful category. The quality of care received during evacuation and the frequency of parental visits were also found to be significantly associated with attachment style for female respondents. Irrespective of experience of evacuation, both male and female respondents who reported poor home nurture showed a similar low incidence of secure attachment of 23% compared to those from homes with good quality care of 45% and 43%, respectively, with concomitant increases in proportions in the dismissing category for males and the fearful category for females. The clinical implications of the study are briefly discussed.