Dementia, Mild Cognitive Impairment Tied to Suicide Risk

Older VA patients with mild cognitive impairment (MCI) or dementia were at higher risk for attempting suicide, a longitudinal study found.

In a fully-adjusted model, the risk for attempting suicide was 23% higher among those diagnosed with dementia (HR 1.23, 95% CI 1.05-1.44, P=0.01) and 34% higher in patients with MCI (HR 1.34, 95% CI 1.09-1.65, P=0.005), reported Amy Byers, PhD, MPH, of University of California San Francisco and the San Francisco VA Health Care System, and colleagues in JAMA Psychiatry.

And the risk for attempting suicide was highest for patients with "recent" initial diagnoses of cognitive impairment (i.e., after 2013):

• MCI: adjusted HR 1.73 (95% CI 1.34-2.22, P<0.001)
• Dementia: adjusted HR 1.44 (95% CI 1.17-1.77, P=0.001)

The study analyzed records of 147,959 participants who had used VA health services from 2007 to 2013, including 21,085 with MCI diagnoses, 63,255 with dementia, and 63,255 without either diagnosis; participants' mean age was 74.7. They were then followed through December 2016.

A total of 138 patients with MCI (0.7%) and 400 patients with dementia (0.6%) attempted suicide during follow-up, compared with 253 patients without MCI or dementia (0.4%).

While the participant groups with MCI and dementia had markedly higher rates of psychiatric comorbidities such as depression, PTSD, and anxiety, than the comparison group, moderation analyses showed that the presence of psychiatric disorders had no statistical significance regarding MCI or dementia and risk of suicide attempt.

William Frey II, PhD, director of the Alzheimer's Research Center at Regions Hospital at the University of Minnesota, suggested that the study's finding of greater suicide risk in the MCI group could stem from their relatively better cognitive function versus those who receive a dementia diagnosis.

"Because the actual effects on their brain and their cognitive abilities are less, they are probably in a position to feel more intensely about the consequences of receiving this verbal diagnosis," Frey told MedPage Today.

On the other hand, he pointed out that the risk of suicide attempt increases across the board among people learning that they have a life-threatening and often horrible illness. For example, previous studies have shown that adult patients who receive cancer diagnoses have a 20% increased risk of suicide than the general population.

But for Paul Aisen, MD, director of the Alzheimer's Therapeutic Research Institute at USC's Keck School of Medicine, there is a uniquely unsettling quality to an MCI or dementia diagnosis.

"There's something particularly frightening about anticipating the loss of self that is dementia," Aisen said. "That's not to say that suicide attempts are common, it's that the risk is greater."

Byers and colleagues, as well as both Frey and Aisen, said the homogeneity of the study's population -- almost all men and mostly white, as customary in VA data -- was an important limitation.

Ronald Petersen, MD, PhD, director of the Alzheimer's Disease Research Center at the Mayo Clinic in Rochester, Minnesota, said that, while the study sample does diminish the generalizability, it doesn't diminish the study's importance. For him, it's a call for clinicians to think critically about the way that they deliver an MCI or dementia diagnosis to their patients.

"Clinicians need to be mindful that people receive these diagnoses in variable ways," Petersen said. "We need to be aware of the fact that this may have a significant psychological impact on people."

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