Laura Heath, Ph.D., of the University of Washington and colleagues examined the health data of 3,059 older adults who were part of Kaiser Permanente Washington’s Adult Changes in Thought (ACT) study, a longitudinal study tracking brain changes prior to the onset of dementia.
The investigators used this longitudinal data to compare dementia rates in patients with cumulative antidepressant use, which was divided into four categories of medication exposure over the previous decade: none, low (1 to 90 days), medium (90 days to one year), high (1 to 3 years), and very high (3+ years). Antidepressants were also grouped into five categories: paroxetine, other SSRIs, serotonin antagonist and reuptake inhibitors (SARIs), tricyclic antidepressants, and all other antidepressants.
Heath and colleagues identified no association between antidepressant use and dementia risk for most groups of antidepressants, regardless of how much medication people took. In contrast, some patients with a history of paroxetine use (high and low use groups) were found to be at a statistically significant increased risk of dementia compared with those with no antidepressant use; patients in the medium and very high categories also showed higher risk, but it was not significant. The authors suggested these findings point to paroxetine posing a dementia risk that is not based on cumulative exposure to the medication.
The authors also found that patients with a low exposure to SARIs such as trazodone had a slightly lower risk of dementia. Some preclinical evidence has hinted that trazodone might have neuroprotective properties, but this connection needs further investigation, the authors said.
“Given the primary results and the sensitivity analyses that showed higher risk of dementia … in [paroxetine] users with depression than in nonusers with depression, who may already be at higher risk of dementia because of depression, our findings suggest that some caution may be warranted in prescribing paroxetine for depression in older adults,” the authors concluded.
For related information, see the Psychiatric News article “Long-Term SSRI Use May Slow Progression to Alzheimer’s Dementia.”