Alcoholism and timing of separation in parents: findings in a midwestern birth cohort

Abstract

Objective: We examined history of alcoholism and occurrence and timing of separation in parents of a female twin cohort.

Method: Parental separation (never-together; never-married cohabitants who separated; married who separated) was predicted from maternal and paternal alcoholism in 326 African ancestry (AA) and 1,849 European/ other ancestry (EA) families. Broad (single-informant, reported in abstract) and narrow (self-report or two-informant) measures of alcoholism were compared.

Results: Parental separation was more common in families with parental alcoholism: By the time twins were 18 years of age, parents had separated in only 24% of EA families in which neither parent was alcoholic, contrasted with 58% of families in which only the father was (father-only), 61% of families in which only the mother was (mother-only), and 75% in which both parents were alcoholic (two-parent); corresponding AA percentages were 59%, 71%, 82%, and 86%, respectively. Maternal alcoholism was more common in EA nevertogether couples (mother-only: odds ratio [OR] = 5.95; two parent: OR = 3.69). In ever-together couples, alcoholism in either parent predicted elevated risk of separation, with half of EA relationships ending in separation within 12 years of twins' birth for father-only families, 9 years for mother-only families, and 4 years for both parents alcoholic; corresponding median survival times for AA couples were 9, 4, and 2 years, respectively. EA maternal alcoholism was especially strongly associated with separation in the early postnatal years (mother-only: birth-5 years, hazard ratio [HR] = 4.43; 6 years on, HR = 2.52; two-parent: HRs = 5.76, 3.68, respectively).

Conclusions: Parental separation is a childhood environmental exposure that is more common in children of alcoholics, with timing of separation highly dependent on alcoholic parent gender.

Figure 1

Family-level study participation. Shown are numbers of families (European or other ancestry, African ancestry) and percentages relatives to total target population of like-sex twins, where at least one twin completed Waves 1, 4, or 5 interviews, subgrouped by presence or absence of parent interview data. Also shown are families where only a screening interview was completed and families never enrolled in the study, with the latter subgrouped by contact history.

Figure 2

Kaplan—Meier failure curves of time to separation as a function of parental alcoholism and offspring age, by broad versus narrow measure, for European or other ancestry and African ancestry families.