Mental Illness in Dementia Patients

Dementia of all kinds, specifically Alzheimer’s disease, comes with many unfortunate mood and behavior changes. However, sometimes these changes are not side effects of the dementia, but mental disorders that merely accompany dementia, causing more stress in the patient’s life. If these disorders are properly recognized and treated, the treatment can also improve the overall affliction of Alzheimer’s disease.


Anxiety occurs in approximately 5 to 10% of adults in long term care, and one-third of older adults who also have a major depressive disorder. It is important to note that when these disorders are co-occurring, they may be associated with future dementia.

Anxiety in patients with dementia may present symptoms such as restlessness, irritability, pacing, anger, agitation, stress or nervousness about upcoming events, and fear of being left alone. They may follow a caregiver closely when anxious or mirror their caregiver’s emotions and stress, which can add to their anxiety.

The treatment to reduce anxiety symptoms and preserve cognition includes a stable daily routine, rituals, consistency with caregivers, and a calm environment with pleasant surroundings.  Reducing unrealistic demands on the part of the caregiver can also reduce anxiety and its symptoms.


Depression is prevalent in persons with dementia. It is found in 30-40% of residents with Alzheimer’s dementia, 30-40% of those with Parkinson’s disease, 35-50% of those with vascular dementia, and 50-60% of those with Lewy Body dementia. Forgetfulness can also be a symptom of depression, though this is often incorrectly interpreted as dementia.

Depression often follows acute and chronic conditions such as Huntington’s and Parkinson’s disease. If a person with dementia has previously been stable and suddenly declines or has an increase in symptoms, a depression screening could be insightful. Some of the symptoms that could increase include irritability, agitation, resisting care, verbal and physical aggression, and refusing medication and therapy. The patient may also appear apathetic or withdrawn, though this indifference does not guarantee that they are depressed, as apathy can be a symptom of some diseases like Parkinson’s. However, Anhedonia, or no longer finding pleasure in activities that you once did, is a symptom of depression.

If depression is diagnosed, cognitive function can be preserved by beginning therapies sooner rather than later. These therapies can include starting an SSRI such as Zoloft, exercising, cognitive behavioral therapy, and individual counseling. All of these treatments help to address and treat depression and preserve cognition.

Chronic Mental Illness

Chronic Mental Illness (CMI) such as Schizophrenia can also co-occur with dementia. Chronic psychiatric illnesses may cause a neurocognitive deficit as well as deficiencies in attention, memory, and executive function as part of their symptomology and disease Process. CMI can require a person to be on an antipsychotic medication lifelong. This can cause complications such as hypertension, diabetes, and dyslipidemia, which can also lead to cognitive decline. It is important to note that cognitive decline persists when other symptoms of Schizophrenia are in remission. Fortunately, many of these symptoms and disease states caused by antipsychotics can often be controlled with medication, diet, and exercise, which will help preserve cognition.

Many long-term care residents who have Schizophrenia are 20 years younger than their long-term care peers. Most older persons with Schizophrenia have been taking antipsychotics for as long as decades, and some may have cognitively and physically declined, requiring less medication. Often with decline, these persons may be able to tolerate and even do better with less medication. 

Patient Awareness

It is essential to be aware of a patient’s symptoms and note when they change. If someone with dementia or Alzheimer’s disease also is experiencing anxiety, depression, or an underlying CMI, all aspects of their condition should be evaluated and treated. More often than not, treating the anxiety will improve the behaviors and quality of life in persons with dementia. Addressing the dementia can also help with other mental illnesses. Evaluating and treating all of the patient’s conditions help them most as a whole.