Depression and Suicide in Aging Veterans: SMITREC Initiatives

Older adults comprise the fastest-growing segment of the U.S. population, with the most significant growth among those over age 80. The percentage of older veterans is even higher than in the general population (37 percent vs. 13 percent), and from 2000 to 2010, veterans age 85 plus will triple to 1.3 million. A considerable number of older veterans experience depression which is associated with substantial suffering, disability, suicide risk, and decreased health-related quality of life. The majority of elders with depression receive treatment in primary care settings where depression is often inadequately treated.

Depression Diagnosis and Treatment

While depression in elderly patients is highly treatable, the complexity of patients’ clinical presentations may result in underdiagnosis and undertreatment, which, in turn, lead to poor outcomes and increased health care utilization. SMITREC investigators have found low rates of diagnosis of mental disorders such as depression in the elderly among primary care providers.¹ A screening tool increased rates of diagnosis and intervention, but did not alter age-related disparities.

Patient factors, such as medical illness, neuropsychiatric comorbidity, and patient beliefs, also interact with provider factors to produce less than optimal management and outcomes. SMITREC investigators have found significantly lower rates of depression detection by treating physicians among subjects with coexisting dementia and depression. ² Only 35 percent of the coexisting dementia and depression group were correctly diagnosed and receiving adequate treatment for their depression. Treatment inadequacy had both provider-level (lack of guideline-concordant antidepressant titration) and patient- and caregiver-level (lack of adherence) contributions. Patient ethnicity may also play a role: SMITREC investigators have documented significantly lower rates of depression diagnoses in older African Americans as compared to older white and Hispanic patients.

Antidepressant treatment is as efficacious for major depression in elderly patients as in younger adults. However, many elderly patients discontinue medications prematurely; SMITREC investigators have found that up to a third of depressed older veterans did not consistently fill antidepressant prescriptions during acute treatment. Thus, while we have effective treatments for depression for elderly veterans, many veterans do not adhere to them for multiple reasons, including cognitive impairment and beliefs that are often culturally mediated. A current Investigator-Initiated Research grant led by SMITREC investigators is examining the relationship between clinical factors (such as anxiety, polypharmacy, and executive impairment) that may be key modifiable determinants of antidepressant non-adherence for older veterans with depression. Our goal is to develop a framework for new interventions to improve adherence among this vulnerable population.

Patients with severe depression, as well as dementia and depression or other neuropsychiatric symptoms require additional pharmacological management. However, in 2005, the FDA warned that use of atypical antipsychotics to treat neuropsychiatric symptoms of dementia was associated with increased mortality. SMITREC investigators found that antipsychotic medications were associated with increased mortality in patients with dementia compared to most other medications used for neuropsychiatric symptoms.³ This association is not well understood, and may be due to a direct medication effect or to the pathophysiology underlying neuropsychiatric symptoms that prompt antipsychotic use. A current NIMH R01 grant led by SMITREC investigators is exploring the relationship of antipsychotic use, mortality, and underlying cognitive impairment severity and neuropsychiatric symptoms further within the older veteran population.

Aging and Suicide

SMITREC investigators also are leading two federally funded grants that examine suicide among veterans in depression treatment. Overall, veterans in depression treatment had a suicide rate of 88.25 per 100,000 person-years over a five year observation period. Patient-level predictors of suicide among this treatment population were generally congruent with predictors in the general population; however, suicide risks associated with age differed. In this depression treatment population, younger veterans (aged 18–44 years) had a moderately higher rate of suicide than did middle-aged patients (94.98 versus 77.93 for patients aged 45–64 years) and also modestly higher rates than elderly patients (94.98 versus 90.06 for patients aged 65 years or older).⁴ The reasons for these findings are unclear, but suggest that when older patients are actively engaged in depression treatment, their suicide risks may be no higher than that of other patients.

SMITREC continues to address critical issues to the older veteran with depression. Future SMITREC efforts will be directed to developing and implementing best practice models to effectively identify and treat later-life depression in our aging veteran population.

References

1. Valenstein M, et al. Psychiatric Diagnosis and Intervention in Older and Younger Patients in a Primary Care Clinic: Effect of a Screening and Diagnostic Instrument. Journal of the American Geriatrics Society 1998; 46:1499-1505.
2. Kales HC, et al. Rates of Clinical Depression Diagnosis, Functional Impairment and Nursing Home Placement in Coexisting Depression and Dementia. American Journal of Geriatric Psychiatry 2005; 13:441-9.
3. Kales HC, et al. Mortality Risk in Patients with Dementia Treated with Antipsychotics versus other Psychiatric Medications. The American Journal of Psychiatry 2007; 164:1568-76.
4. Zivin K, et al. Suicide Mortality among Individuals Receiving Treatment for Depression in the Veterans Affairs Health System: Associations with Patient and Treatment Setting Characteristics. American Journal of Public Health 2007; 97:2193-8.

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