Vascular depression. Comorbid depressive symptoms and vascular disease—or “vascular depression”—can cause ischemic brain lesions, cognitive impairment, increased apathy and retardation, and impaired fluency and naming.12
What defines vascular depression has been debated. Watch for clinical or laboratory evidence of vascular disease, depression, and neuropsychological impairment.13
Treatment: searching for evidence
Two days after admission, Mr. B is transferred to the ICU after suffering severe hypoglycemia and showing signs of medically induced delirium. Elevated creatinine (1.7 mg/dL) indicates acute renal failure, which could be related to his elevated serum lithium (1.7 mEq/L). Acting on the internist’s advice, the consulting psychiatrist stops lithium and restarts valproate, 500 mg bid.
Mr. B becomes medically stable after 3 days, mostly through acute IV hydration and by withholding oral diabetes medications, which normalizes his blood sugar. He is transferred back to the psychiatry unit. We try lithium again at 300 mg bid, but creatinine and serum lithium quickly rise.
Mr. B remains hospitalized for 3 months with severe, treatment-resistant depression. Trials of nearly every second-generation antipsychotic (SGA) cause symptomatic orthostatic hypotension, leading to several falls. He does not respond to divalproex, up to 2,000 mg/d; citalopram, 60 mg/d; mirtazapine, 30 mg at bedtime; venlafaxine, 100 mg tid; or bupropion, 100 mg tid.
We suggest electroconvulsive therapy (ECT) but Mr. B declines, saying this treatment caused his mother to decompensate. We try lamotrigine, 25 mg/d, and titrate it over 6 weeks to 200 mg bid. After we add haloperidol, 5 mg at bedtime, and bupropion, 300 mg/d, Mr. B becomes mentally stable.
The authors’ observations
Numerous clinical challenges—such as managing complicated/refractory BPD, medical comorbidity, and medication adherence (Box)14,15—complicate treatment of late-life BPD.16 Regular communication with providers and integrating health care services can minimize complication risk.16
Pharmacotherapy, a core element of BPD treatment, is challenging in older patients because of their:
- heightened threat of complications and sensitivity to side effects because of age-related pharmacokinetic changes
- increased risk of drug-drug interactions
- increased potential for age-related psychosocial problems (increased social isolation, financial difficulties, demoralization, increased stress, inability to work).
Medication adherence a problem? Try educational/cognitive approach
Initial clinical and laboratory evaluations can rule out aggravating or causative factors and identify conditions that can cause drug intolerability.5 Check orthostatic vital signs and perform a detailed medical and psychosocial history, neurologic examination, ECG, and cognitive evaluation.Between 40% and 60% of patients do not take medications as prescribed.14 That percentage probably is higher among cognitively impaired older adults because cognitive problems can compound other causes of nonadherence.
Few published controlled clinical trials have addressed adherence interventions for older adults. Educational approaches combined with cognitive supports are most likely to succeed. Ownby et al15 hypothesized that effective approaches usually employ multiple components including counseling, information reminders, and family therapy.
Techniques for improving adherence include:
- addressing the patient’s beliefs about his or her illness
- exploring how patient characteristics affect medication adherence
- use of memory aids, such as 7-day pill boxes
- working with caregivers
- prescribing lower-than-normal dosages to minimize side effects.
Consider side effects, medical and neurologic comorbidities, and treatment history before prescribing a mood stabilizer, antipsychotic, or antidepressant to an older patient. Avoid unwarranted discontinuation of a previously effective agent, such as when drug concentrations are elevated or inadequate—as happened with Mr. B.5 Also investigate the patient’s side-effect history before stopping a medication.5
Medications. Mr. B’s inability to tolerate lithium posed a treatment challenge. Adjusting lithium dosages to compensate for age-related pharmacokinetic, pharmacodynamic, and renal clearance changes can prevent toxicity.5 Avoid stopping lithium abruptly, as this can trigger recurrence of manic or depressive episodes.17
Lamotrigine, indicated for BPD maintenance therapy, appears to prevent depressive/mood relapse. Compared with other anticonvulsants, lamotrigine might cause fewer negative effects on cognition and less induction of hepatic enzymes. It is well tolerated by older patients but has not been studied adequately in this age group.16
Antipsychotics are widely used in BPD,16 especially when psychosis is present with mania or depression or the patient is agitated. Most studies of antipsychotics in BPD have followed younger adults, however, and most studies in older patients have followed those with dementia or schizophrenia.
Use of first-generation antipsychotics such as haloperidol is especially challenging in the elderly because these drugs increase risk of cardiovascular effects, extrapyramidal symptoms, and tardive dyskinesia and can cause depression in BPD.16 By comparison, SGAs carry a lower risk of involuntary motion18 but can increase risk of obesity, diabetes, and dyslipidemia. However:
- The need to manage psychosis usually overrides concerns about metabolic sequelae.
- Older patients might be less susceptible to metabolic effects,16 though this has not been confirmed.