Dementia has traditionally been regarded as a disorder of cognitive function alone. However, contemporary psychiatric perspectives recognize it as a much broader and more complex syndrome. Primary (neurodegenerative) dementias are frequently accompanied by a range of psychiatric disorders, which have a significant impact on patients’ quality of life, functional abilities, and care needs. This coexistence increases the burden not only on patients but also on their family members and places additional demands on healthcare systems.

It is now well established that psychiatric symptoms are not merely accompanying features but are often an integral part of the dementia phenotype. Dementia may be complicated by depression, anxiety, psychosis, apathy, agitation, and behavioral disturbances, all of which can substantially influence the course and progression of the disease.

Psychiatric Symptoms in Dementia

In neurodegenerative diseases, psychiatric symptoms often arise directly from the underlying biological processes of the disease. The risk of developing these symptoms is increased by several factors, including:

• A family history of psychiatric disorders
• Uncontrolled pain
• Systemic illnesses (particularly those associated with delirium)

Studies have shown that the majority of individuals with dementia develop psychiatric symptoms within approximately five years of disease onset. The most common symptoms include:

• Apathy
• Depression
• Anxiety
• Irritability

Apathy is of particular clinical importance because it is often persistent and tends to progress as the disease advances. In contrast, other psychiatric symptoms are more likely to occur episodically.

Characteristics of Psychiatric Manifestations Across Different Types of Dementia

Alzheimer’s Disease

The most common psychiatric manifestations in Alzheimer’s disease include:

• Apathy
• Depression
• Anxiety
• Agitation
• Delusions

Hallucinations and manic-like states are relatively uncommon.

Vascular Dementia

Vascular dementia is characterized by psychiatric symptoms similar to those seen in Alzheimer’s disease, particularly:

• Apathy
• Depression
• Anxiety
• Irritability

Parkinson’s Disease Dementia

The following psychiatric manifestations are especially common in Parkinson’s disease dementia:

• Visual hallucinations
• Illusions and pareidolia
• Paranoia and delusions
• Anxiety and depression

REM sleep behavior disorder is also a characteristic feature of this condition.

Huntington’s Disease

Huntington’s disease is characterized by three major clinical components:

• Cognitive impairment
• Affective symptoms (including depression and irritability)
• Motor disturbances (including chorea and tics)

Frontotemporal Dementia

In frontotemporal dementia, psychiatric and behavioral symptoms are often central to the diagnosis. Common manifestations include:

• Socially inappropriate behavior
• Impulsivity
• Compulsive behaviors
• Emotional blunting
• Hyperphagia

Diagnosis and Assessment

A detailed medical history plays a crucial role in the assessment of the psychiatric aspects of dementia. It is essential to obtain information from family members or caregivers, as individuals with dementia are often unable to accurately assess or report their own symptoms.

The assessment should include:

• Establishing the chronology of symptoms
• Assessing symptom severity
• Identifying pre-existing psychiatric disorders
• Evaluating environmental and psychosocial factors
• Excluding underlying physical illnesses

The mental status examination should include both cognitive assessment and a comprehensive evaluation of behavior, mood, and perception.

Apathy vs. Depression

Distinguishing between apathy and depression is essential:

• Apathy → Emotional indifference without sadness
• Depression → Persistent sadness, feelings of guilt, and pessimism

Agitation and Behavioral Disturbances

Agitation may be triggered by a variety of underlying factors, including:

• Infection
• Pain
• Fear
• Sleep disturbances

Management should focus on:

• Identifying and addressing the underlying cause
• Ensuring the patient’s safety
• Modifying the environment to reduce distress and agitation

Delirium and Sleep Disturbances

Delirium is an acute clinical condition that is commonly associated with:

• Infections
• Medications
• Metabolic disturbances

Sleep disturbances are also very common in individuals with dementia. Their management primarily relies on non-pharmacological interventions, such as light therapy and the establishment of a regular daily routine.

Social and Functional Impact

Psychiatric symptoms in dementia can:

• Reduce quality of life
• Accelerate disease progression
• Increase the likelihood of institutionalization
• Contribute to caregiver burden and burnout

Management and Treatment

Multidisciplinary Approach

Effective management requires a multidisciplinary team involving:

• Physician
• Nurse
• Psychologist
• Physiotherapist
• Social worker

Education of both the patient and the caregiver is also essential. Whenever possible, the involvement of an occupational therapist is highly recommended.

Non-Pharmacological Interventions

• Establishing a structured daily routine
• Adapting the environment to the patient’s needs
• Using verbal de-escalation techniques
• Reducing distressing or excessive environmental stimuli

Additional interventions include:

• Music therapy
• Physical activity
• Aromatherapy (e.g., lavender and lemon balm)
• Light therapy
• Massage and therapeutic touch

Pharmacological Treatment

Anxiolytics: Benzodiazepines and other hypnotic/sedative agents should generally be avoided in individuals with dementia because of their adverse effects on cognition, increased risk of falls due to excessive sedation, and the potential for paradoxical reactions, such as agitation.

Antidepressants: Selective serotonin reuptake inhibitors (SSRIs), particularly citalopram and escitalopram (10–20 mg/day), have been shown to be beneficial in managing agitation and depression in patients with Alzheimer’s disease. As an alternative, trazodone (starting dose: 25 mg at bedtime) is generally well tolerated and is frequently used to improve sleep disturbances in individuals with dementia. Sertraline has also demonstrated acceptable efficacy and tolerability in clinical studies. More recently, vortioxetine has emerged as an effective and well-tolerated treatment option for patients with dementia, particularly because of its potential to improve cognitive function in addition to treating depressive symptoms. The U.S. Food and Drug Administration (FDA) recommends a maximum daily dose of 20 mg of citalopram or escitalopram in adults aged 60 years and older. These medications should be avoided in patients at increased risk of cardiac arrhythmias, such as those with congenital long QT syndrome, hypokalemia, hypomagnesemia, or active heart disease.

Mood Stabilizers:

• Carbamazepine demonstrated efficacy in a placebo-controlled study involving nursing home residents with early-stage dementia who exhibited agitation. Relatively low doses (300 mg/day) were used. However, subsequent studies failed to confirm this benefit, and a systematic review concluded that there is currently insufficient evidence to recommend carbamazepine for the treatment of neuropsychiatric symptoms in dementia.
• Valproate has been shown to reduce aggressive behavior. However, a systematic review found that neither immediate-release nor extended-release formulations were effective in treating the neuropsychiatric symptoms of dementia. In addition, the potential risk of hepatotoxicity should be carefully considered.
• Gabapentin is frequently prescribed because of its relatively favorable side-effect profile, although its efficacy for the treatment of neuropsychiatric symptoms in dementia has not been established.
• Lamotrigine has been recommended based primarily on case reports and is considered to have a relatively favorable safety profile compared with other mood stabilizers.

Sleep–Wake Disturbances: For sleep–wake disturbances, melatonin at doses ranging from 1.5 to 10 mg may be used.

Antipsychotic Medications: Atypical antipsychotics are considered the treatment of choice for managing psychotic symptoms and agitation in patients with dementia. However, these medications are associated with an increased risk of mortality and should therefore be prescribed with caution.

When pharmacological treatment is necessary, one of the following agents is generally preferred:

• Olanzapine may be initiated at 2.5 mg/day and gradually increased to a maximum dose of 5 mg twice daily. It has demonstrated moderate efficacy in the treatment of neuropsychiatric symptoms in patients with Alzheimer’s disease or vascular dementia.
• Quetiapine is an alternative option. Treatment is typically initiated at 25 mg at bedtime and may be titrated up to a maximum dose of 75 mg twice daily.

In patients with dementia, first-generation (typical) antipsychotics should generally be avoided, particularly injectable formulations, because of their less favorable safety profile.

Recommendations

• Screening: Neuropsychiatric symptoms are common in dementia and are major contributors to nursing home placement and caregiver distress. Clinicians should routinely screen for these symptoms during patient assessments.
  Assessment of underlying causes: When a patient with dementia develops neuropsychiatric symptoms, the first step is to identify potential precipitating factors and to evaluate for, exclude, and treat any underlying medical condition or delirium.
• Non-pharmacological interventions: Environmental, behavioral, and other non-pharmacological approaches can be effective in managing neuropsychiatric symptoms and should be considered first whenever possible. If pharmacological treatment is required, medications with the lowest risk of adverse effects should be preferred.
• Pain management: Pain may exacerbate behavioral disturbances in patients with dementia. It is important to determine whether pain is a transient symptom or a persistent source of distress and to manage it appropriately.
• Role of cholinesterase inhibitors: Cholinesterase inhibitors do not produce clinically significant improvements in neuropsychiatric symptoms. Nevertheless, they are commonly prescribed to patients with dementia because of their beneficial effects on cognitive function.
• Depression: Selective serotonin reuptake inhibitors (SSRIs) are recommended for the treatment of depression in Alzheimer’s disease. Citalopram and escitalopram are frequently used because they may also improve other neuropsychiatric symptoms; however, the daily dose should not exceed 20 mg in older adults. Sertraline is another well-studied alternative. Vortioxetine has also demonstrated efficacy and safety in older adults and offers the additional advantage of improving cognitive function. Tricyclic antidepressants should generally be avoided because of their adverse effects and potential drug interactions.
• Severe or treatment-resistant agitation: Antipsychotic medications have limited efficacy and are associated with an increased risk of mortality in patients with dementia. However, treatment may be justified when symptoms are severe and pose a risk to the safety of the patient or caregiver. When antipsychotic therapy is necessary, olanzapine or quetiapine at the lowest effective dose is generally preferred.
• Dementia with Lewy bodies (DLB): Patients with DLB are at particularly high risk of severe adverse reactions to antipsychotic medications. When pharmacological treatment of behavioral symptoms is unavoidable, only very low doses of certain atypical antipsychotics (e.g., quetiapine or clozapine) should be used.
• Apathy: Apathy may occur either with or without coexisting depression. Management strategies include treatment with a cholinesterase inhibitor, a therapeutic trial of an antidepressant, and, in selected cases, low-dose methylphenidate.

Conclusion

From a psychiatric perspective, dementia is a complex and multifaceted syndrome in which cognitive impairment and psychiatric symptoms are closely intertwined. Contemporary clinical practice requires not only the assessment of cognitive deficits but also the proactive identification and management of neuropsychiatric symptoms.

Effective management is based on an individualized, multidisciplinary, and holistic approach, with particular emphasis on non-pharmacological interventions and the optimization of the patient’s environment. Ultimately, the goal is not only to reduce symptoms but also to preserve the patient’s quality of life to the greatest extent possible.

References

1. Benjamin J. Sadock, Virginia A. Sadock, and Pedro Ruiz, Kaplan and Sadock’s Synopsis of Psychiatry (Publisher, Year), page number, Chapter 3.2 “Neurocognitive Disorders (Dementia).”
2. Blitzstein, Sean M., Latha Ganti, and Matthew S. Kaufman. First Aid for the Psychiatry Clerkship. 6th ed. New York: McGraw-Hill Education, 2021. Chapter 8: “Neurocognitive Disorders.”
3. https://www.uptodate.com/contents/management-of-neuropsychiatric-symptoms-of-dementia?search=dementia%20treatment&topicRef=5080&source=see_link&searchCorrelationId=e2be131b-90cb-425d-9827-cc1ce9256282&searchCorrelationTerm=dementia%20treatment