Diffusion of new generation antidepressant treatment among elderly diagnosed with depression

This study analyzes the prevalence of new generation antidepressant treatment including selective serotonin reuptake inhibitor (SSRI) use from 1992 to 1997 among the elderly diagnosed with depression, using a large, nationally representative survey of Medicare beneficiaries. Relationships between use of new generation antidepressant treatment and socioeconomic characteristics, physical comorbidity, insurance coverage, and care sector (mental health specialty vs. general health services) are explored.

Merged survey data, Medicare claims, and detailed self-reports from the Medicare Current Beneficiary Survey were used to explore use of new generation antidepressant treatment.SUBJECTS Medicare beneficiaries aged 65 and older living in the community, enrolled in fee-for-service Medicare throughout the year and diagnosed with depression.

In 1997, among an estimated 1.1 million community dwelling older adults with diagnosis of depression in health care claims, nearly two thirds received antidepressant treatments. Among those diagnosed with depression and treated with antidepressants, the use of new generation antidepressants increased from 35% in 1992 to 77% in 1997. The rates of use increased among all subgroups examined. In the early years after the introduction of these new antidepressant medications (1992-1994), there were socioeconomic disparities in use of these medications, with less use by less educated and poor patients. However, these differences abated over time.

An increasing proportion of elderly treated for depression with antidepressants received the new generation antidepressants. The diffusion of these new medications lagged for those with low socioeconomic status defined by education and income. This diffusion process conforms to a general model of diffusion in which during the initial years following introduction of a new treatment, especially one which is costly, early adopters of the treatment are likely to disproportionately represent those of higher socioeconomic status.