Frequency of antidepressant use in relation to recent and past major depressive episodes

There has been a trend toward increasing antidepressant (AD) use in recent decades. We used data from the National Population Health Survey (NPHS) to determine whether this trend is continuing and to provide updated estimates of the frequency of use.

The NPHS is a longitudinal general health survey that began collecting data in 1994. The NPHS evaluates past-year major depressive episodes (MDEs) using a brief diagnostic instrument. At each biannual interview (from 1994 to 2006) current medication use is recorded. We estimated the frequency with which ADs were taken by respondents (aged 12 years and older) with and without past-year MDEs. These frequencies were cross-tabulated by sex, year of interview, and the reported duration of symptoms.

ADs are taken by about 5.4% of the household population at any point in time. Most respondents taking ADs did not report past-year MDEs but 63.9% of respondents taking ADs in the absence of past-year episodes reported previous episodes or being diagnosed by a health professional with depression. This pattern is consistent with long-term treatment for relapse prevention. The overall frequency of use of ADs is increasing only in respondents without past-year episodes.

AD use among community residents with past-year MDEs is no longer increasing. The continued increase in the overall frequency of use may point toward broadening indications for AD treatment and may indicate that people are taking these medications for longer periods of time.