Both smoking and depression appeared to influence each other, even after the researchers factored out alcohol and other substance abuse and delinquent activities, such as skipping school, aggression toward authority figures, vandalism or physical violence toward classmates. But this actually can inhibit the re-uptake of dopamine, one of the neurotransmitters implicated in causing depression when low levels exist in the brain. This can account for the underlying reciprocal relationship between nicotine and negative mood. Furthermore, those who smoke heavily for a number of months may increase their vulnerability to depression because of alterations in brain chemistry. Dr. Myrna Weissman, chief of the division of clinical and genetic epidemiology at the New York State Psychiatric Institute, says both studies are important because they confirm earlier findings about teenage depression.
Teens are very vulnerable to depression when a mother is depressed but untreated.
These studies are very sturdy. Suicide attempts, eating disorders, drug and alcohol abuse and at-risk sexual behavior often accompany depression in teens, she said, noting that pediatricians and family practitioners need to be especially attentive to children of mothers with a history of depression or who are taking antidepressant medications. Weissman said children with depressive symptoms can also alert doctors to the potential of undiagnosed and untreated depression in the mother. The problem is that many people with depression are not identified in the primary care setting. Doctors only have 10 minutes or so to examine a patient, so a lot of these cases go unidentified.