The following are summaries of posters presented at the annual meeting of the American Association for Geriatric Psychiatry in Honolulu in March. The reports are generally preliminary and have not been peer reviewed for publication. They may involve the use of medications for indications not approved by the Food and Drug Administration.

• About 49 percent of U.S. nursing home residents have a diagnosis of dementia, and 30 percent of these dementia patients receive treatment with cholinesterase inhibitors. Dallas Seitz, M.D., and colleagues at the University of Toronto and affiliated Bay-crest Centre, analyzed data from the 2004 National Nursing Home Survey, a national survey of 1,174 U.S. nursing homes involving 11,940 residents over age 65. According to the survey, 71 percent of the cholinesterase inhibitor prescriptions were for donepezil. Among patients who were taking cholinesterase inhibitors, 54.9 percent had mild functional impairment, 19.8 percent had moderate impairment, and 25.3 percent had severe impairment. Other factors associated with increased cholinesterase inhibitor use included younger age, recent admission to a nursing home, and concurrent prescriptions for antidepressants and antipsychotics.

• The severity of a patient's Alzheimer's disease is significantly associated with his or her caregiver's risk for anxiety and depression. Howard Fillit, M.D., of the Alzheimer's Drug Discovery Foundation, and colleagues conducted, in 2007, a self-administered survey of 1,077 unpaid, adult caregivers of Alzheimer's patients, such as spouses, adult children, relatives, and neighbors. The caregivers' burden was rated using the Caregiver Burden Scale, health care visits in the past six months, workdays lost because of care-giving demands, and diagnosis of anxiety or depression. The severity of Alzheimer's in the patients was significantly associated with the overall burden for their caregivers, including a significantly increased number of visits to medical professionals and facilities, missed workdays, and rates of being diagnosed with depression or anxiety. The study was funded by Pfizer.

• One-fourth of older adults taking antidepressants may be at risk for serious drug-drug interactions because of concurrent medications, according to a retrospective analysis of prescription data from a commercial database of Medicare supplemental insurance claims.

Patients 65 years of age or older who had a diagnosis of depression and filled at least one antidepressant prescription from 2001 to 2006 were included. A drug-information software program was used to identify whether two drugs with known contraindications or serious interactions were filled during overlapping days. Examples of pairs of medications often taken at the same time include some selective serotonin-reuptake inhibitors (SSRIs) and tramadol, sertraline with oxycodone, and amitriptyline with the antibiotic drug trimethoprim/sulfamethoxazole. Because most antidepressants are metabolized in the liver by the cytochrome P450 isoenzymes, potential interactions with other hepatically metabolized drugs are common.

According to the study report, approximately 25 percent of older patients with depression who fill prescriptions for antidepressant medications" also take other medications with their antidepressants" in a combination that is considered "contraindicated" and may lead to life-threatening consequences. Further, "co-prescriptions" with the potential for "major" interactions may complicate antidepressant prescribing by leading to more antidepressant switching.

Levels of severity of drug interactions were defined as" contraindicated/major," deemed life threatening and/or requiring medical assistance; "moderate," which may worsen the health of the individual; and "minor/no potential," which indicates minimal or no side effects.

The research was carried out by Tami Mark, Ph.D., M.B.A., and colleagues at the University of Southern California, the University of South Florida, and Rutgers University. The database is owned by Thomson Reuters, and the study was funded by Sanofi-Aventis U.S.

• Older patients taking SSRIs and serotonin norepinephrine reuptake inhibitors (SNRIs) had a significantly greater risk of upper gastrointestinal bleeding than those who were not taking these medications. The retrospective study analyzed medical and prescription drug data of patients aged 65 or older in a large Medicare managed care claims database from 2001 to 2006. The rates of having an upper GI bleeding event within the 12 months after starting a medication were similar between patients on an SSRI/SNRI and those on a nonsteroidal anti-inflammatory drug (NSAID), with hazard ratios of 1.87 and 1.66, respectively, of the rate in patients taking neither medications (controls). Taking both an SSRI/SNRI and an NSAID increased the hazard ratio to 3.1 compared with control patients. The study was conducted by David Sheehan, M.D., M.B.A., of the University of South Florida College of Medicine, and colleagues. It was funded by Sanofi-Aventis U.S.

• Older African-American patients being treated for depression reported encountering a higher level of stigma due to their mental illness than did their white counterparts. Janet Kavanagh, M.D., and colleagues at the University of Michigan and at the Veterans Affairs Ann Arbor Healthcare System surveyed older depressed patients treated in primary care clinics using the Stigma Scale for Receiving Psychological Help. The scale contains five questions, each with a rating of 0 to 3. Among the 44 African-American participants and 102 white participants, the African-American patients reported significantly higher rates of perceived stigma on the total score and three individual questions indicating that they were more likely to agree with the statements on feeling stigmatized for receiving treatment and professional help for depression. The authors noted that perceived stigma for mental illness and psychiatric treatment can be a significant barrier to getting help among minority patients. The study was funded by a grant from the National Institute of Mental Health (NIMH).

• Older adults with nonpsychiatric medical illness and physical disability but without depression have a substantial risk of developing depressive symptoms within a year of starting home-care services. Mark Weinberger, Ph.D., and colleagues at Weill Cornell Medical College interviewed 268 older adults who were admitted to a Medicare-certified, home-care service agency in Westchester County, N.Y. At the time of starting the home-care service, the patients had a mean age of 77.9 years and showed no evidence of depression, nor were they taking any antidepressant medications. When a follow-up interview was conducted 12 months after baseline, 28 patients (10 percent) had major or minor depression as determined by the Structured Clinical Interview for DSM-IV (SCID), the 17-item Hamilton Depression Rating Scale (HDRS), and other instruments. Two baseline factors significantly predicted later development of depression: subjective rating of current health and self-reported somatic symptoms consistent with items in the HDRS. The study was funded by NIMH grants.

• As many as 6.2 percent of older adults in the primary care setting may have suicidal ideation even though they do not screen positive for depression. Amy Byers, Ph.D., M.P.H., and colleagues at Weill Cornell Medical College analyzed data on 515 participants in the Prevention of Suicide in Primary Care Elderly: Collaborative Trial (PROSPECT) who did not report either anhedonia or depressed mood. All participants were aged 60 or older and seen in primary care sites. Of the 32 participants with suicidal ideation, 21 had at least one symptom on the SCID other than anhedonia and depressed mood, and 90 percent of these 21 participants reported fatigue and/or sleep problems (mostly insomnia). The authors suggested that primary care clinicians should consider asking about suicidal ideation in patients who complain of fatigue or insomnia even if they deny other hallmark symptoms of depression. The PROSPECT study was primarily funded by NIMH, with small grants from Forest Laboratories and the John A. Hartford Foundation. ▪