"While smoking and depression adversely affect a mother's health, the combination may also affect the health of her child," Whitaker said.
In the study, the data for the analysis came from the Fragile Families and Child Wellbeing Study, in which 4,898 mothers were surveyed at the time of delivery, from 1998 to 2000. In a follow-up survey 15 months later, 4,353 (89 percent) of mothers reported their smoking behaviour and symptoms of a major depressive episode during the prior 12 months.
The analysis of the follow-up survey showed that the 12-month prevalence of a major depressive episode was 46 percent higher among smokers and that the prevalence of smoking was 33 percent higher among those who had a major depressive episode in the prior 12 months.
"Most recently, healthcare policy has focused on children's access to healthcare, but we also have to keep the mother's health in the discussion," Whitaker said. "A paediatrician will often see an infant who is wheezing and who has a mother who smokes. The mother may also have symptoms of depression. However, paediatricians often lack the time, skills and mandate to treat the mothers. A better referral network of adult healthcare providers might be one way to help the paediatrician help these mothers, and to, in turn, help the children," Whitaker said.
The potential consequences of maternal smoking in children include sudden infant death, asthma, ear infections and attention deficit/hyperactivity disorder, while the potential consequences of maternal depression include behaviour problems, language delay and childhood depression.
"Giving a mother who smokes the telephone number to a 'quit line' is probably not going to be enough if smoking is helping the mother cope with her symptoms of untreated depression," Whitaker said. "Depression and addiction to tobacco should not be diagnosed or treated in isolation from each other," he added.
The study claimed that the issue was, particularly, troublesome for low-income families. "Unfortunately, an adequately financed primary-care system for low-income mothers does not exist beyond pregnancy. You can improve the well being of the child by addressing the health and well being of the mother. Care of mothers and their children should be better integrated in our healthcare system," Whitaker said.
The study is published in Preventive Medicine.