The frequency of depression in adolescence and young adulthood is associated with later mental health and economic problems, according to a new study from New Zealand.
Depression is relatively common among adolescents and young adults, and is often a recurrent condition. This study, published in the October 2007 issue of the British Journal of Psychiatry, collected information from a 25-year longitudinal study of 982 New Zealand children born in the Christchurch urban area in mid-1977.
The children were monitored at birth, 4 months, 1 year, annually to the age of 16, and the again at ages 18, 21 and 25. At ages 18, 21 and then 25, study participants took part in a structured interview measuring mental health and psychosocial adjustment. Education and economic outcomes were also measured at ages 21-25.
Other factors that might affect depression were also taken into account, including family living standards, family stability, physical punishment or sexual abuse in childhood, gender, parental attachment, neuroticism, self-esteem and association with deviant peers. Participants were also assessed for a range of psychiatric disorders other than depression, including anxiety and substance misuse.
It was found that, overall, 35.1% of those studied met criteria for major depression on at least one occasion between the ages of 16-21, 22.7% reported 2 or more episodes, and 3.9% reported 10 or more episodes. Females had significantly and substantially more episodes than males (204.8 per 100 v. 100.4 per 100).
An increasing number of depressive episodes from ages 16-21 was significantly associated with higher rates of mental health problems at ages 21-25, including major depression, anxiety disorder, suicidal thoughts and suicide attempts.
Increasing frequency of depression at ages 21-25 was significantly associated with declining education and economic outcomes at ages 21-25, including lower rates of degree attainment or any higher education qualifications, being welfare-dependent, unemployed and having a low income at age 25.
Exceptions to these findings were that depression in adolescence and early adulthood was not associated with reduced educational achievement at age 25 after confounding factors had been taken into account. Further, the association with unemployment was no longer found after adjustment for confounding factors and other psychiatric disorders.
The authors of the study comment that their results suggest that frequency of depression in young people predicts later psychiatric and life-course outcomes, including subsequent depression, anxiety, suicidal behaviours and welfare dependence, even after controlling for confounding factors and other psychiatric disorders.
This study underlines the importance of developing effective methods for identifying, managing and treating depressive episodes in adolescence and early adulthood. For a minority of young people, major depression will be a chronic and recurrent condition that both reduces their psychological well-being and limits their life opportunities.
The treatment of depression in young people might serve to reduce risks of later mental health problems other than depression, and might also have the effect of reducing levels of welfare dependence.
“Recurrence of major depression in adolescence and early adulthood, and later mental health, educational and economic outcomes”
Fergusson DM, Bodden JM and Horwood LJ (2007)
British Journal of Psychiatry, 191, 335-342.
bjp.rcpsych.org
