Parental absence in early childhood as a result of death or relationship break-down is linked to a heightened risk of starting to smoke and drink alcohol before that child reaches his/her teens, indicates research published online in the Archives of Disease in Childhood.
Previous research suggests that childhood adversities are associated with poorer mental and physical health in adulthood, and the 'loss' of a parent has been linked to a heightened risk of smoking and drinking in adolescence and later life.
But what is not clear is whether parental absence is a risk factor for an even earlier start on 'risky' health behaviours, or what the potential impact might be of the child's sex, the age at which they experienced their loss, or which parent they lost.
The researchers therefore drew on data from the UK Millennium Cohort Study, which has been tracking the health of almost 19,000 children born between 2000 and 2002, in regular surveys.
The first of these was carried out 9 months after birth, with subsequent surveys when the children were 3, 5, 7 and 11 years old.
At the age of 11 the children were also asked whether they had ever smoked or drunk alcohol, and whether they had ever consumed enough to feel drunk.
Parental absence was defined as the 'loss' of a biological parent before the child was 7 years old.
In all, the researchers had complete data for almost 11,000 children, more than one in four of whom had experienced the 'loss' of a parent by the age of 7.
Most children had not smoked by the age of 11, although among those that had, this behaviour was more likely among the boys: 3.6% vs 1.9% of the girls.
Drinking alcohol was more common, with boys once again more likely to have tried it: around 1 in 7 of them (almost 15%) and around 1 in 10 of the girls (10.6%) said they had ever drunk alcohol.
Of those that had tried alcohol, around twice as many of the boys--nearly 12% compared with 6.6% of the girls-- were likely to say that they had consumed enough to feel drunk.
Analysis of the data showed that children who had experienced parental absence before the age of 7 were more than twice as likely to have taken up smoking and 46% more likely to have started drinking alcohol by the age of 11.
These findings held true even after taking account of potentially influential factors, such as educational attainment of the parent(s); mother's ethnicity; mother's age at parenthood; smoking during pregnancy; length of pregnancy; and birthweight.
Similarly, the child's sex, the age at which they first experienced parental absence, or which parent was missing, had no bearing on the findings.
However, while children who had lost a parent through death were less likely to have drunk alcohol by the age of 11, those that did, were more than 12 times as likely to get drunk than were children whose parent was absent for other reasons.
"Associations between parental absence and early smoking and alcohol consumption may operate through a range of mechanisms, such as reduced parental supervision, self-medication, and adoption of less healthy coping mechanisms," write the researchers.
"For instance, nicotine in particular demonstrates psychoactive properties and may have benefits for mood regulation."
This is an observational study so no firm conclusions can be drawn about cause and effect. And, as with all long term studies, missing data are a potential source of bias. Furthermore, no information was included on parental absence between the ages of 7 and 11, which may have influenced behaviour, the researchers point out.
Nevertheless, their findings echo those of other studies in this area, they say, emphasising that health behaviours established in early life are known to set patterns for later life.
Research: Parental absence in early childhood and onset of smoking and alcohol consumption before adolescence
About the journal:
Archives of Disease in Childhood is one of 60 specialist journals published by BMJ. The title is co-owned with the Royal College of Paediatrics and Child Health.