Patients with dementia taking some antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), experienced faster cognitive decline compared with those not taking these medications, according to a study issued this week in BMC Medicine.
Minjia Mo, Ph.D., of the Karolinska Institutet in Stockholm, and colleagues used Swedish nationwide registries to identify 18,740 individuals (54% women, average age of 78 years) who were diagnosed with dementia from 2007 to 2018. The registries included information on prescription medications and participants’ cognitive trajectories, evaluated at baseline and follow-ups using the Mini-Mental State Examination (MMSE). Severe dementia was defined as an MMSE score of less than 10 (lower scores indicate worse cognition). Nearly 23% of participants received at least one prescription for an antidepressant during the six months leading up to their initial dementia diagnosis or a subsequent follow-up, with SSRIs accounting for about 65% of prescriptions.
Adults taking antidepressants experienced faster cognitive decline during follow-up compared with non-use (an additional 0.3-point loss on the MMSE per year). Among adults who had severe dementia at baseline, those taking antidepressants experience an additional 1.5-point loss on the MMSE per year.
The researchers also individually examined the six most common antidepressants prescribed. All three SSRIs on the list—escitalopram, sertraline, and citalopram—were associated with greater cognitive decline compared with non-use. Compared with sertraline, escitalopram presented with faster cognitive decline, while citalopram was linked to a slower cognitive decline. Mirtazapine, a noradrenergic and specific serotonergic antidepressant, was also associated with faster cognitive decline compared with non-use, whereas venlafaxine (a serotonin norepinephrine reuptake inhibitor) and amitriptyline (a tricyclic) were not.
“Sertraline and escitalopram are firsthand choices for depression among older individuals in Sweden,” Mo and colleagues wrote. “However, antidepressants do not seem to work as well in patients with dementia.” They said their findings support the idea that depression in dementia is different from depression in people with intact cognition.
“Future research is needed to further elucidate the complex interplay between antidepressant use, dementia severity, and cognitive decline,” the authors continued. “Our study cannot distinguish whether these findings are due to the antidepressants or the underlying psychiatric indication.”
For related information, see the Psychiatric News Alert “SSRIs May Increase Risks Associated With Anti-Amyloid Alzheimer’s Medications.”
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