Older adults with depressive disorder (MDD) have a substantially worse prognosis than their younger counterparts. A 2-year observational study showed that the course of MDD worsened linearly with age, in individuals aged 70 years and older had the worst outcomes.

"Because the course of the major depressive disorder is more unfavorable in old age, it might be worthwhile to treat depression more intensively," lead author Roxanne Schaakxs, Ph.D., of the Amsterdam Public Health Research Institute, Department of Psychiatry, VU University Medical Center, the Netherlands, told.

"For example, we might use a multidisciplinary approach with strict monitoring, in which multiple health professionals are involved and cooperate," Schaakxs said.

Inconsistent Methodology

It is expected that almost one-fifth of adults will have at least one episode of MDD at some point during their lives, but the course of such episodes "can be highly variable," the authors noted.

Previous studies, said Schaakxs, show that the course of MDD is more unfavorable in older age. However, she noted that studies with "solid methodology" that carefully take into account other prognostic factors are lacking.

In previous studies, "age groups were often inconsistent for example, one study would classify a 55-year-old as 'young,' where another would classify the person as 'old' making it hard to compare the studies and obtain a clear conclusion," she added.

To accomplish that, they used data from two cohort studies: the Netherlands Study of Depression and Anxiety (NESDA), and the Netherlands Study of Depression in Older Persons (NESDO). The studies included a total of 1042 participants aged 18 to 88 years (66% women).

Individuals of insufficient capacity to participate in the study, those who had received a primary clinical diagnosis of dementia, or those who had a severe psychiatric disorder other than depressive and anxiety disorders were excluded. Participants were also required to be outpatients.

At baseline, the DSM-IV-based Composite International Diagnostic Interview (CIDI, lifetime version) was used to determine the presence of depression, and the self-report Inventory of Depressive Symptomatology (IDS-SR) was used to assess depression severity.

New Treatment Avenues

Commenting on the study for John Zajecka, MD, associate professor of psychiatry and clinical director of the Depression Treatment and Research Center at Rush University Medical Center, Chicago, Illinois, who was not involved in the study, said the study "reinforces the notion that traditional antidepressants may not work in all people."

Recent research into the biological mechanisms of depression, including the role of inflammation, glutamate, and endogenous opioids, may facilitate the expansion of the treatment armamentarium into new avenues with potential utility in the geriatric population, he said.

Zajecka suggested a treatment approach similar to that taken in hypertension, cancer, or infectious diseases, "where we may need to combine different treatments to achieve the desired outcome, which is complete remission."