Mohammed T. Abou-Saleh

Principles and Practice of Geriatric Psychiatry.Editors: Professor John R. M. Copeland, Dr Mohammed T. Abou-Saleh and Professor Dan G. BlazerCopyright & 2002 John Wiley & Sons LtdPrint ISBN 0-471-98197-4 Online ISBN 0-470-84641-085Epidemiology and Risk FactorsS. Lehmann and P. RabinsJohns Hopkins Medical Institutions, Baltimore, MD, USAIn recent years there has been renewed research and clinicalinterest in the syndrome of mania in the elderly. Much of thecurrent work in this area has been focused on the following issues:can mania first present in late life?; do the causes, features, clinicalcourse, and responsiveness to treatment differ in older manicpatients compared to younger persons with mania?; how doelderly manic patients with an early age of onset of illness differfrom those with onset of illness in late life?EPIDEMIOLOGYThe manic phase of bipolar affective disorder, or mania, is anuncommon disorder in the elderly. In the five-site EpidemiologicCatchment Center study of more than 20 000 non-institutionalizedindividuals, 1 month prevalence rates for mania were 0.4–0.8%for 18–44-year-olds and 0.2% in the 45–64-year-old group.Notably, no cases of mania were identified among people overage 64 1 .Nevertheless, elderly patients with mania are seen in significantnumbers in a variety of clinical settings. In Roth’s 2 retrospectivereview of 464 psychogeriatric patients over age 60 in a long-termhospital, 14 cases were manic. This represented 6% of the totalnumber of cases of affective disorder. Two studies of firstadmissions to British psychiatric hospitals, using Department ofHealth statistics, found that the number of first admissions withmania either remained steady with age 3 or increased withadvancing age 4 . In the USA, other studies in short-stay hospitalshave reported that mania accounted for approximately 5% ofelderly psychiatric admissions 5,6 . Similarly, one recent studyidentified 39 patients over age 60 with bipolar, manic or mixedstate disorder out of 791 inpatient admissions (approximately 5%)over a 4 year period 7 . Most studies of elderly manic patients havefound more females than males 5–8 but one recent report found aslight male preponderance 9 .For the majority of elderly bipolar patients, the first episode ofaffective disorder is usually a depression. Indeed, it is quitecommon for a first manic episode to occur 10 years or more afteran initial depressive episode and to be preceded by multipledepressive episodes over many years 5,10,11 . Generally, elderlypatients have been found to have suffered more episodes ofdepression before a first manic episode and to have had a long gapbetween an initial depression and a first manic episode than youngmanic patients 11 .It must be noted that, at the present time, there is no agreeduponstandard regarding which age should serve as the dividingline between early and late onset of bipolar illness. Furthermore,age of onset itself is often difficult to determine with exactitude.Different criteria have been used among various investigators toidentify age of onset, including first onset of symptoms, firsthospitalization and first time at which the patient met full criteriafor the disorder 7 . Several recent studies have observed bi-modalityin age of onset of mania among elderly patients. In these studies,one subgroup of patients was found to have developed bipolardisorder in early life with a mean age in their 30s, and anothersubgroup developed a first manic episode after age 60 7,11 . Lateonsetbipolar patients tend to have had a longer gap between firstdepression and first mania than early-onset bipolar patients 11 ,and in one study were more likely to be married or living with asignificant other 7 .RISK FACTORSA number of studies have reported that elderly bipolar patientswho had an early age of onset were more likely to have had firstdegree relatives with affective disorder than late-onset elderlybipolar patients 11,12 . This trend holds across studies that have usedages between 20 and 60 years to divide early and late cases andsuggests that genetics plays a greater role in the disease of earlyonsetbipolar disorder. At the same time many investigators havereported associations between late-onset mania and cerebrovascularand neurologic disease. A cohort study comparing 50elderly patients with mania to 50 age- and sex-matched patientswith unipolar depression found that 36% of the manic patientshad neurological disorders compared with only 8% of thedepressed patients 13 . Interestingly, among these neurologicallyimpaired manic patients, 33% had a positive family history ofaffective disorder in first-degree relatives. In another recent studycomparing elderly patients with early- and late-onset bipolardisorder, researchers found that patients with late-onset illnesswere more likely to demonstrate cerebrovascular risk factors orclinical evidence of cerebrovascular disorders 7 . In a prospectivestudy of mania in 35 patients over age 60, the elderly manicpatients had more cortical atrophy on CT scans than age-matchedcontrols 11 . However, no significant difference in cortical atrophywas found between elderly patients with early- and late-onsetmania. In addition, subcortical hyperintensities have beenreported on magnetic resonance imaging (MRI) in elderly patientswith mania 14 . These hyperintensities are believed to be due tofocal loss of brain parenchyma but they do not seem to be specificto elderly patients with mania, since subcortical hyperintensitieshave also been found in late-onset depression as well as late-onsetparanoid disorders 15 .Krauthammer and Klerman 16 proposed criteria for secondarymania, which included cases of no prior family history, no priorPrinciples and Practice of Geriatric Psychiatry, 2nd edn. Edited by J. R. M. Copeland, M. T. Abou-Saleh and D. G. Blazer&2002 John Wiley & Sons, Ltd