Both common, yet elusive, symptoms of depression, dementia, and delirium may overlap in older adults, which provides a diagnostic challenge. Even more confounding, these three disorders, the three Ds of geriatric psychiatry, frequently present simultaneously. In this episode, we will review key features to help distinguish between these disorders and provide some tips on their management.

Publication Date: 10/09/23

Duration: 16 minutes, 24 seconds

Transcript: 

STEPHANIE COLLIER: Both common, yet elusive, symptoms of depression, dementia, and delirium may overlap in older adults, which provides a diagnostic challenge. Even more confounding, these three disorders, the three Ds of geriatric psychiatry, frequently present simultaneously. In this episode, we will review key features to help distinguish between these disorders and provide some tips on their management.

Welcome to the Carla Psychiatry Podcast. This is an episode from the Geriatric psychiatry team. I'm Stephanie Collier, the editor in chief of the Carlat Geriatric Psychiatry Report.

NEHA JAIN: And I'm Neha Jain, editorial board member of the Carlat Geriatric Psychiatry Report and an associate professor of psychiatry at UConn Health.

STEPHANIE COLLIER: We have some exciting news for you. You can now receive CME credit for listening to this episode and all new episodes going forward on this feed. Follow the podcast CME subscription link in the show notes to get access to the CME post-test for this episode and future episodes.

NEHA JAIN: So, let's delve right in and begin talking about the first of the three D's, which is depression.

Depression is often experienced by older adults as depression without sadness and can show up as anhedonia, a lack of pleasure, or physical symptoms such as fatigue, general malaise, and apathy. Older adults are also at a higher risk of experiencing psychotic symptoms of depression, with delusions present up to 45 percent of older adults admitted to hospital because of depression.

Most commonly, the psychotic symptoms may manifest as auditory hallucinations, which are often negative comments, paranoia, or nihilistic delusions, as in everything's coming to an end, the world is in a very dark place. In the latest issue of the CARLAT Geriatric Psychiatry Report, Dr. Mayan mentions that when patients experience visual hallucinations, she thinks first about delirium, Lewy body dementia, eye conditions, or brain injury.

Patients with an increased vascular burden in the brain and a history of stroke, are at high risk for depression, and depression is also frequently seen as a non-motor symptom of Parkinson's disease.

STEPHANIE COLLIER: It's also important to mention that apathy, which is a lack of motivation or interest in the absence of a subjectively low mood, may mimic depression, but is actually a common early symptom of dementia.

NEHA JAIN: I'm so glad you explained that Dr. Collier. Thank you, Dr. Collier. When screening for depression. I usually get basic labs to rule out reversible causes, such as blood counts, electrolytes, liver and kidney function, as well as thyroid labs, vitamin D, vitamin B12 levels, and any other labs that might be indicated by the risk factors of that particular patient. The Geriatric Depression Scale is a GDS short form is a helpful screener for depression in older adults. In patients who don't have a prior history of depression, it is important to ask about any concerns about cognition, as late onset depression can be a sign of abutting neurocognitive disorders. In all patients with depression, always assess for suicide risk factors, as older adults and 3 in particular have the highest risk for complete suicide.

STEPHANIE COLLIER: So what are the best ways to manage depressive symptoms?

NEHA JAIN: Some of the more popular first choice treatments for depression include selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors, or SNRIs, and mirtazapine. It is important in older adults to begin at low doses and then slowly work your way up to the target dose, stopping or waiting any time that's needed.

For example, if you're starting mirtazapine, we'll start at 7. 5 milligrams or even 3. 25 milligrams in frailer patients and then slowly increase in 5 to 7. 5 milligram per week intervals to get to the target range of 15 to 30 milligrams at bedtime. Individual psychotherapy interventions including cognitive or CBT, problem solving therapy or PST, and interpersonal therapy or IPT, are considered evidence based for treatment of late life depression. And again, these interventions can be administered individually, one on one, or in a group setting. And then you should consider things like bright light therapy and exercise, which do have efficacy in non-seasonal late life depression.

STEPHANIE COLLIER: And what about neuromodulation? How does transcranial magnetic stimulation, or TMS, compare to electroconvulsive therapy, for example?

NEHA JAIN: Yeah, that's a good question. TMS is a great option, but so far it is still shown to be less effective than ECT. So, for treatment refractory depression or severe depression, ECT still remains the gold standard. And what I especially like is that it's so much better tolerated in the elderly even compared to medications.

STEPHANIE COLLIER: Let's move on to the next D, dementia. Dementia is a decline in cognitive function that impacts your activities ADLs. As we know, the most common cause of dementia is Alzheimer's disease, which is characterized by the subtle yet harmful progression of symptoms, such as short-term memory loss and word finding difficulties over the years. However, when a patient's cognition begins to change over days or weeks, it makes sense to think about the other two Ds, depression or delirium, and not dementia. What kind of assessments can we use for dementia?

NEHA JAIN: Typically, we'll screen cognition using the Mini Mental Status Exam or the MMSC, Montreal Cognitive Assessment or the MOCA or the St. Louis University Mental Status Examination, or SLUMS. We will usually order a same set of labs as we do for depression, and then think about brain imaging, either a head CT or a brain MRI, especially if you suspect an atypical dementia, see any focal neurological signs, or suspect a large vascular burden.

STEPHANIE COLLIER: When thinking about managing the symptoms of dementia, of course we want to optimize nonpharmacological treatments first. These include problem solving therapies, psychosocial interventions, and caregiver support. Activity scheduling and enhancing daytime structure may improve apathy associated with dementia. Other treatments include cognitive enhancers, such as Cholinesterase inhibitors, memantine, and melatonin, which can help to alleviate some of the symptoms of dementia. Cholinesterase inhibitors are used for mild, moderate, or severe dementia, while memantine is reserved for moderate to severe cases. Melatonin can be helpful for maintaining a normal sleep wake cycle in patients with dementia.

NEHA JAIN: And then there is the last of the three Ds, delirium. Delirium is a state of acute confusion due to either a medical illness or sometimes it's treatment. It develops more quickly, usually over a course of hours or maybe days, and tends to fluctuate in severity. Delirium is considered the lupus of psychiatry. It can masquerade as many other illnesses. Patients with hypoactive delirium may look more depressed. Those with hyperactive delirium may appear manic or psychotic. And those with straight confusion may appear intoxicated or even cognitively impaired. In patients with delirium, acute changes in the environment can lead to rapid decompensation. The pathophysiology of delirium includes dysregulation of multiple neurotransmitter systems, disrupting the networks in the brain. Although delirium is less common in the community, it occurs in 10 to 30 percent of hospitalized older patients. Dr. Collier, how should clinicians assess for delirium?

STEPHANIE COLLIER: In older adults with delirium, our priority is to rule out life threatening causes. We generally start with a review of a patient's vital signs and nursing notes to appreciate the time course of the patient's altered mental status. We then review all medications, paying close attention to those known to cause delirium such as benzodiazepines, anticholinergics, and opioids. You want to then think about infections with UTIs and pneumonia as being the most common in older adults. Then you want to think about electrolyte abnormalities, alcohol or benzodiazepine withdrawal and other medical illnesses. Your screening labs typically include a complete blood cell count, a complete metabolic panel, thyroid function tests, urinalysis and urine culture, and you can consider a chest x ray. Finally, you want to evaluate whether the patient is experiencing pain, hunger, constipation, or changes in sleep patterns. You can then move on to the psychiatric differential. In a patient with delirium, highest on our differential is dementia. You can assume every older adult with delirium has an underlying dementia, until proven otherwise. But also consider apathy, depression, and catatonia. To quickly and accurately screen for delirium in older adults, you can use the 3D confusion assessment method or the CAM screening tool. This screener includes four features that help distinguish delirium from other types of cognitive impairment.

NEHA JAIN: When thinking about how to differentiate between depression, dementia, and delirium, timing is very important. Cognition that worsens over days and sometimes hours and fluctuates is most consistent with delirium. Dementia can progress over months and years, but it can certainly underlie delirium, as Dr. Collier just explained. And delirium, especially hypoactive delirium, can also mimic depression.

STEPHANIE COLLIER: So how do we differentiate these conditions from one another?

NEHA JAIN: That's, again, a very important clinical question that often comes up in the hospital and clinics. I think testing attention is probably key because if attention is intact, then you know that the patient is not delirious. The fastest way to assess attention is to ask patients to recite the months of the year or days of the week backwards.

And remember, if the patient is delirious, then you really can't make any other psychiatric diagnosis, either depression or dementia in its presence, as delirium holds the place of diagnostic privilege, so to speak.

STEPHANIE COLLIER: For management of delirium, non-pharmacological interventions have the best evidence. And they can reduce the incidence of delirium by up to 40%.You want to try to keep your patients with delirium awake and alert during the day by engaging in activities and conversation, as well as keeping them out of bed if possible. Keep the windows open to sunlight during the day. Keep the rooms dark and relatively undisturbed for sleeping at night. This delirium affects the sleep wake cycle, wander guards, door alarms, and G P S chips can help ensure patient safety in case they wander at night.

NEHA JAIN: We try to avoid anti-psychotics unless physical aggression or psychosis are severe enough to pose danger to the patient or to others. It is important to weigh the benefits of decreasing agitation with the side effects of antipsychotics, especially in patients with underlying dementia, given the FDA's black box warning of an increased risk of death in individuals with dementia when on antipsychotics. For physical aggression that does not respond to non-pharmacological methods, you can start with quetiapine, 12. 5 to 25 milligrams, or olanzapine, 2. 5 to 5 milligrams, either at bedtime or in split doses. You can also consider haloperidol, 0. 5 to 1 milligram. Again, as needed, which does have the advantage, it's available as PO, IM, or IV.

Although antipsychotics can help with agitation, they don't really have an effect on either the severity of delirium, the resolution of other symptoms, or mortality. So, if an antipsychotic is initiated during an episode of delirium, it is important to try to taper or discontinue it once the symptoms resolve.

STEPHANIE COLLIER: For sleep, you can consider a low dose melatonin or remeltion. Cholinesterase inhibitors do not have a role in the prevention or treatment of delirium, although they can be continued in patients already taking them for dementia. Benzodiazepines, which are deliriogenic, are the preferred treatment for benzodiazepine or alcohol withdrawal.

We recommend educating family members about the symptoms of delirium and how the symptoms of delirium can shift and alternate for weeks to months, depending on the severity of the underlying medical condition. To manage the expectations of loved ones, you might discuss that the patient may or may not return to their cognitive baseline.

Overall, in this podcast, we discussed how to disentangle the three Ds, depression, dementia, and delirium, through screeners and medical workup, and how to optimize their management. It's helpful to use screeners because these disorders can occur simultaneously. And the symptoms can overlap. For depression, first make sure to check labs to rule out reversible causes. You can consider the screener the Geriatric Depression Scale, or GDS, short form. When screening for dementia, you can use the MMSE, MOCA, or SLUMS. And finally, when assessing for delirium, you can use the CAM or confusion assessment method, which includes four features that help distinguish delirium from other types of cognitive impairment.

NEHA JAIN: The newsletter clinical update is available for subscribers to read in the Carlat Geriatric Psychiatry report. Hopefully people will check it out. Subscribers get print issues in the mail and email notifications when new issues are available on the website. Subscriptions also come with access to all the articles on the website and CME credits.

STEPHANIE COLLIER: And everything from Carat publishing is independently researched and produced. There is no funding from the pharmaceutical industry.

NEAH JAIN: Yes, the newsletters and books we produce depend entirely on reader support. There are no ads and our authors don't receive industry funding. That helps us to bring you unbiased information that you can trust.

STEPHANIE COLLIER: And don't forget, you can now earn CME credits for listening to our podcasts. Just click the link in the description to access the CME post-test for this episode.As always thanks for listening and have a great day!

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