An understanding of bipolar disorder in the elderly makes it easier to assess and treat, maximizing care delivery and patient outcomes.

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ipolar disorder in late life is poorly understood,¹ and its symptoms may impair resident function while complicating our ability to provide appropriate care. This article reviews diagnostic criteria of selected bipolar spectrum disorders focusing on diagnostic dilemmas in the elderly, discusses comorbid illnesses and common differential diagnoses, and outlines considerations in care planning and medication monitoring in the long-term care environment.

The DSM-IV: Diagnostic Confusion in the Elderly?

       Mood disorder diagnosis is built from symptoms. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) outlines symptom presentations from severe depression to frank mania, and specific mood disorder diagnoses are then established by combining mood symptoms with timelines and other qualifiers. While this method of diagnosis has been beneficial in creating uniform diagnostic guidelines, it has created diagnostic dilemmas in special populations including the elderly; geriatric patients presenting with less-dramatic symptoms of bipolar disorder may be overlooked. Comorbid illnesses, a habit of searching for a single cause for multiple symptoms, and a focus on acute symptomatic treatment rather than chronic management all complicate diagnostic clarity. A quick review of symptoms in the bipolar spectrum makes it easy to imagine the dismissal of these presentations in the elderly, especially if other diagnoses (eg, dementia) are present.
       With the development of safe and effective treatment options for depression, recognition of depression in elderly patients has improved. No longer is it dismissed as a consequence of aging and untreated. But this increased awareness of depression has been slow to spread to other mood disorders. The result has been a frequent interpretation of bipolar, especially manic and hypomanic presentations, as “behavioral disturbances” rather than a possible mood disorder.
       The potential consequences of delayed or nontreatment of bipolar disorder include advancement of the disease state, an increased likelihood of developing treatment resistance and deterioration in resident function,² and a potential worsening of medical comorbidities.³ Reaching a correct diagnosis, incorporating appropriate guidelines in care planning and treatment, and educating family and staff present us with the best opportunity for maximizing outcomes in this serious illness.

Prevalence

       Data regarding the frequency of bipolar disorder in the elderly reflect an uneven awareness, with prevalence rates in persons 65 years of age and above ranging from less than 1% to over 19% of the population. A large epidemiological study by the National Institute of Mental Health (NIMH) in the 1980s estimated a rate of bipolar disorder in those 65 years of age and above of approximately 0.1%,⁴ but later studies suggest this may be a gross underestimation. Bipolar disorder currently accounts for about 10% of gero-psychiatric hospital admissions.⁵ Late onset of bipolar disorder is not uncommon, and it frequently presents with a significant time between a first depressive episode and mania,⁶ with an average latency of 15 years. Multiple depressive episodes may occur in the interim, prior to the first manic episode,^7,8 with a resultant tendency to continue a diagnosis of depression and attribute the manic symptoms to another cause.

Comorbid Illness and Mortality

       Bipolar disorder symptoms including impaired judgment and insight, impulse disinhibition, and associated noncompliance with medication management, increase the severity of comorbid illnesses as well as the mortality rate in elderly bipolar patients.^9,10
       Psychiatric and other medical comorbidities are common. Anxiety disorders, including generalized anxiety disorder and panic, have been reported at higher lifetime rates among elderly bipolar patients than among controls.¹¹ High rates of comorbid borderline personality disorder have been noted,3 and epidemiologic studies reveal significant lifetime rates of alcohol and drug use disorders.
       Very limited research into bipolar disorder in geriatric populations has been completed. Bipolar disorder descriptions have historically focused on mood elements of the illness, with dementia descriptions routinely describing cognitive and functional decline. Increasing acknowledgement of the behavioral aspects of dementia as well as awareness of the cognitive effects of bipolar disorder has revealed an intriguing overlap between the pair of presentations. A common presentation of manic symptoms in the elderly, including confusion, disorientation, and distractibility, may be mistaken for dementia or delirium. As a result, many bipolar presentations may be attributed to the comorbid illness. Studies suggest a potential dementia prodrome with increased mood and affective symptoms, including an association between late-life onset of bipolar disorder and the emergence of dementia.¹² Depression, apathy, or manic symptoms may occur after a stroke, with both vascular depression and vascular mania often comorbid with dementia.

Diagnostic Considerations

       While diagnostic tools for bipolar disorder may eventually be developed from recent and ongoing neuroimaging and related studies,^13,14,15 for now diagnosis remains clinical, with the patient’s history paramount in reaching an accurate diagnosis. Although new-onset mania can occur in late life, a pattern of behaviors consistent with a previously undiagnosed bipolar disorder may be revealed through a thorough history. Persons with bipolar disorder have significantly higher rates of having been fired or laid off from jobs, and rates of arrests, convictions, and jail time are also significantly higher. The likelihood of having never been married or having been divorced is higher.¹⁶ Even if a new nursing home resident is stable and appears to have no mood disturbance on admission, the identification of past patterns of dysfunction at the time of the initial history may allow for quick diagnosis if symptoms recur.
       While the importance of a thorough history cannot be overemphasized, late-onset bipolar disorder, with a first episode occurring after the age of 50, is less likely to be associated with genetic predisposition, and the course of the disease may be less severe than earlier-onset presentations.¹⁷
       Multiple bipolar disorder screening instruments are available for use in community settings, but their direct use in long-term care is of limited benefit. The Mood Disorder Questionnaire (MDQ) (available at www.bipolarhelpcenter.com/resources/mdq.jsp) is a patient-rated screening tool that may be of benefit in cognitively intact residents, and it can also be useful as a teaching tool for increasing staff awareness of possible symptoms of mania or hypomania. In addition, incorporating concepts or questions from the MDQ into the social history may reveal behavioral patterns consistent with an undiagnosed bipolar disorder. The DIGFAST mnemonic (available at www.medscape.com/viewarticle/439472_5) is also a useful, quick tool that staff can use to identify behavioral patterns consistent with mania.
       The most effective diagnostic tool in the long-term care setting is the careful documentation, by all disciplines, of resident behaviors. Documentation should include accurate descriptions of observed behavior rather than vague terms like “agitation,” with the severity, frequency, and timing of the behavior also recorded.
       As with any new onset of mood symptoms, a potential medical etiology should be ruled out before a diagnosis of bipolar disorder is made. A manic presentation may be the result of a number of other causes, alone or in combination. Delirium is common in the elderly, with very high rates reported in continuing care settings, including nursing homes.¹⁸ Delirium presentations may resemble primary mania or bipolar disorder.¹⁹ The diagnosis is further complicated by the potential of delirium to wax and wane for many months following the resolution of an underlying medical illness (eg, urinary tract or upper respiratory infection). Post-ictal states in the elderly with seizure disorders may last for days and mimic symptoms of a severe mood disorder.²⁰ Traumatic brain injury (TBI) is associated with increasing irritability with each subsequent injury,²¹ and post-TBI syndrome may resemble mania or mixed mania, with elation, grandiosity, and depressive symptoms.²² Frank mania occurs in 7–9% of TBI patients, independent of injury severity.²³ Psychiatric symptoms may develop in a significant percentage of patients receiving corticosteroids, with mania and depression most prevalent.²⁴ Risk does not appear to be associated with age,²⁵ although higher doses may increase the risk.
       Any depression symptoms should trigger monitoring for other mood symptoms and consideration of possible bipolar disorder, but atypical depression presentations are more likely to occur in bipolar disorder than other depressive presentations.

Treatment

       In the long-term care setting, treatment considerations extend beyond the individual patient. Severe behavioral outbursts, including those associated with bipolar disorder, may directly impact other residents, staff, and family members. While containment of emergent problems and other safety considerations must be addressed, treatment of bipolar disorder should be focused on the disease itself and not purely on the current “crisis.”²⁶
       Obstacles to the effective treatment of bipolar disorder in this setting include clinical factors (eg, multiple potential comorbid illnesses and metabolic alterations associated with aging) as well as potential limitations in social support structures. Treatment guidelines for medication management of bipolar disorder are routinely designed for younger patients, and many of the standard therapies approved for mania or bipolar disorder in younger populations may present special difficulties when applied to the elderly. Federal guidelines require documentation of the need for psychotropic medications. Off-label prescribing, although common,²⁷ presents potential legal entanglements if not carefully documented.
       Psychotherapy for bipolar disorder as an adjunct to pharmacotherapy has been studied extensively in younger patients,²⁸ but potential benefit in the long-term care setting, especially for patients suffering from dementia, may be limited. Psychotherapeutic interventions should center on psycho-education of staff and family with a goal of increasing awareness of prodromal signs of mood episodes and as an aid in monitoring symptoms and treatment response.
       Psychopharmacologic interventions should center on selecting agents with the greatest likelihood of improving patient outcomes. While many medications may resolve symptoms acutely, long-term stabilization of bipolar disorder is the goal in treatment. Risk-benefit analyses, ease in dosing, patient acceptance, titration, and monitoring are all factors in successful medication management.
       Metabolic abnormalities and a symptom cluster often referred to as the “metabolic syndrome,” including abdominal obesity, impaired glucose tolerance, hyperlipidemia, and hypertension, have been associated with specific psychiatric diseases, including bipolar disorder.²⁹ There are also numerous studies examining the likelihood of some or all of these factors being triggered or exacerbated by use of various medications with a recent focus on atypical antipsychotics, but these findings are based on younger populations. While monitoring for metabolic abnormalities should be conducted in the elderly as in other groups, evidence to suggest an increased risk in this population, even with baseline metabolic abnormalities, is lacking. For atypical antipsychotics, published risks of cerebrovascular adverse events and increased mortality in the elderly with dementia are well known, but the risk of nontreatment or undertreatment may well surpass these risks.
       For off-label usage, familiarity with the medication and its effects are not sufficient. Documentation of the rationale for usage, a risk-benefit analysis, monitoring of response and potential side effects, and informed consent are all important factors in successful treatment. Consultation with other healthcare providers, if needed, should be considered.³⁰

Considerations in Medication Monitoring

       Antidepressants. Persons with bipolar disorder, including the elderly, are more likely to experience depressive mood episodes than manic or hypomanic symptoms. Antidepressants, however,

Table 1

have been linked to mood switch from depression to mania. While at least one study suggests the risk for manic switch is lower in Bipolar II than in Bipolar I patients (see Table 1 for criteria of the disorders),³¹ any geriatric patient started on an antidepressant should be monitored for the onset of mania or hypomania. Tricyclic antidepressants are associated with a higher risk of inducing mania than are selective serotonin reuptake inhibitor (SSRI) agents. Patients with a pre-existing diagnosis of bipolar disorder should be considered for initiation of a mood stabilizer prior to the addition of an antidepressant, if indicated.
       Lithium. The first medication approved by the Food and Drug Administration (FDA) for bipolar disorder, lithium has long been considered the “gold standard” for treatment of younger patients. Age-related changes in body composition make the published therapeutic range for lithium of limited value in geriatric care. Toxicity has been reported in the elderly with lithium levels at low “therapeutic” levels; there is a high risk for central nervous system side effects, and renal failure may result if not carefully monitored. Lithium levels may be increased by dehydration and multiple drugs, including thiazide diuretics, tetracycline, COX-2 inhibitors, non-steroidal anti-inflammatory drugs (NSAIDs), angiotensin-converting enzyme (ACE) inhibitors, and angiotensin receptor agonists. Caffeine, increased dietary sodium, or bicarbonate as well as theophylline may lower lithium levels. Potential cognitive impairment, polyuria, ataxia, and thyroid dysfunction further limit the initiation of lithium treatment in this population.³² If lithium is initiated, slow titration and slow-release forms should be considered to maximize tolerance. Sudden discontinuation should be avoided if possible, as this may prompt an episode of mood instability. Discontinuation of lithium, if necessary, should be done through a slow taper with careful monitoring during and after.
       Anticonvulsants. Multiple anticonvulsant agents have been used in the elderly with bipolar disorder, including valproic acid, carbamazepine, lamotrigine, gabapentin, topiramate, pregabalin, and oxcarbazepine. While these are all antiepileptic agents, there appears to be no “class effect” in treating bipolar symptoms,³³ and each is associated with risk factors, including cognitive impairment.³⁴ Awareness of the safety profile of each, including potential drug interactions, should be incorporated into monitoring. Valproic acid is approved for stabilization of acute mania in bipolar disorder, with excellent data supporting its use as a “add-on” medication to other treatments.³⁵ Lamotrigine is approved for maintenance therapy in Bipolar I disorder, but there are limited data regarding its use in the elderly. Its use in this setting is complicated by the risk of potential serious dermatologic problems and complex titration.
       Antipsychotics. Psychosis is commonly encountered in bipolar disorder, and the use of antipsychotic agents for psychotic symptoms and severe behavioral disturbances has long been accepted in nursing home settings. All atypical antipsychotics show benefit in controlling the symptoms of mania, and olanzapine and aripiprazole have further FDA approval for maintenance use in Bipolar I disorder. Olanzapine, quetiapine, and risperidone are commonly used to address manic and other behavioral symptoms in long-term care. These agents have generally replaced the use of conventional agents like haloperidol in this setting.
       While conventional antipsychotics are rarely recommended for the elderly, warnings associated with newer atypical antipsychotics prompted some providers to return to prescribing these older agents, despite multiple potential risks and questionable safety profiles. Conventional antipsychotic agents are associated with an extremely high rate of tardive dyskinesia in the elderly as well as extrapyramidal symptoms and other side effects. Akathisia from some of these agents may be misinterpreted as increased agitation, prompting a cascade of polypharmacy treatment and potential poorer outcomes.
       Omnibus Budget Reconciliation Act (OBRA) guidelines regarding monitoring of antipsychotics and evaluation for periodic taper refer to their use in behavioral disturbances associated with dementia, but even when used for a bipolar spectrum disorder, monitoring and minimization of effective dose is appropriate.
       Benzodiazepines. These should be considered potential tools in managing acute episodes of mania in the elderly, with close monitoring for increased gait disturbances and for possible disinhibition. Agents with shorter half-lives can serve as an excellent method of acute symptom stabilization and are especially useful during initiation of other medications that may have a delayed onset of action. As-needed prescriptions of benzodiazepines should be time-limited and written with maximum flexibility in scheduling; a lower dosage at increased frequency will allow greater flexibility than higher doses at less frequent intervals, offering the potential for minimization of doses and side effects.

Conclusion

       Understanding bipolar disorder and its relationship to other common geriatric presentations helps us transform difficult presentations into treatable diagnoses. An ability to translate agitation, aggression, apathy, or depression into defined syndromes in geriatric care increases accuracy in assessment and treatment planning and may lead to better patient outcomes.

       Editor’s note: This article was accepted for publication on August 28, 2006.