Mood and Memory Changes in Parkinson's Disease

Most people with Parkinson’s disease notice some decline in their memory and mental agility, even very early in the course of the disease. Chances are that your PD will also affect your thinking to some extent. But the effects are subtle.

Senior couple having serious discussion over lunch at home
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For example, you may notice that it takes you a bit longer to retrieve a memory, come to a decision, calculate a cost or plan a trip. This overall mental sluggishness is influenced by your mood and, in turn, your memory struggles can sometimes negatively influence your mood as well.

The good news is that new research has begun in the area of cognitive rehabilitation that can very effectively reverse this mental sluggishness.

The Profile of Memory and Cognitive Changes

Even in the very early stages of Parkinson's disease people can have difficulty with their thinking processes. Most authorities agree that the primary difficulty lies with the so-called executive cognitive functions.

Executive cognitive functions refer to such thinking processes as memory retrieval, planning, generation of words or concepts, attention, and monitoring and adjustment of non-routine and goal-directed behaviors. The common denominator in all of these executive functions is that they require cognitive control in order to operate smoothly.

The term cognitive refers to processes or operations involved in the processing of all kinds of information. So cognitive control processes are those processes that are used by the mind and brain to regulate the storage, retrieval, and usage of information (thinking).

Problems with executive functions are typically mild in early PD. They usually involve a generalized slowing of cognitive processing speed (bradyphrenia) and subtle deficits in attention and working memory. It may be difficult, for example, to hold two different pieces of information in the mind at the same time, or to efficiently generate words and concepts as quickly as one used to. As the disease progresses, these executive cognitive deficits are made more severe by common Parkinson-related mood disorders and Parkinson-related emotional problems such as depression and anxiety.

Effects of Memory and Cognitive Changes

While it may seem clear to you that emotional states can have a significant impact on your thinking, the reverse is also true: Your thinking can sometimes strongly influence your emotional states. You know the proverbial story of two men who see the same glass of water but one sees it as half full and the other as half empty? The same goes for thinking and emotional states.

Sometimes your assessment of a situation can influence your emotional reaction to that situation. More generally, executive cognitive functions can influence your mood states because those executive functions control all the information you have about the situations you find yourself in. Executive functions control your ‘appraisal’ of those situations. If you find it difficult to recall happy memories, you may become more sad or depressed. If you find it difficult to plan a vacation, you may put off the vacation and thus influence your mood states and so forth.

Problems with executive functions can also get you into trouble over serious matters like money. If you find it difficult to balance the checkbook, you may get a bit sloppier about your finances. Consider also that the extra jolt of dopamine that comes from taking dopamine medications can sometimes make you temporarily more energized and impulsive. Now when you couple a heightened sense of impulsivity with a lowered capacity for thinking efficiently through decisions, you sometimes get impulsive responding—bad decisions.

Caregiver Impact

One final problem with executive functions is that it impacts the caregiver. Many studies have shown that it is more difficult to care for someone who is having difficulties with executive functions than it is to care for someone without cognitive problems.

A Word From Verywell

For all these reasons, it is important to take the memory/cognitive problems that you might have seriously. They may seem minor annoyances, but they can pack a wallop over time. There is no sense letting them go unattended, particularly when there are effective remedies on the horizon—and indeed, there are such remedies.

Cognitive assessments are available to evaluate cognitive problems related to Parkinson's disease. Understanding the most problematic areas for you can allow occupational therapists to design therapy which will be most helpful for you as an individual. Cognitive training, in some cases, has led to long-term improvement in symptoms, especially those related to the speed of processing.

Frequently Asked Questions

  • Does Parkinson’s disease affect memory?

    It can. Some people with Parkinson's disease experience mild cognitive impairment. Brain changes that cause motor symptoms in people with Parkinson's disease can also contribute to deficits in memory, comprehension, and attention. 

    Cognitive changes associated with Parkinson's disease can affect short-term working memory and long-term memory.

  • How quickly does Parkinson's dementia progress?

    Cognitive issues can begin in the early stages of Parkinson’s disease. Executive functioning skills such as memory retrieval, planning, generation of words or concepts, and attention are often the first noticeable cognitive changes. 

    Memory issues can progressively worsen throughout the illness. In addition, mood disorders and emotional problems accompanying Parkinson’s disease can compound memory problems. Depression and anxiety are very common in the later stages of the disease. 

    However, every person with Parkinson’s disease is different. While some people may experience severe cognitive deficits and mood disorders, others may not. 

  • How does Parkinson's disease affect mental health?

    Parkinson's disease–associated brain changes can lead to mood disorders and personality changes. Common mental health conditions that can accompany Parkinson's disease include:

    • Anxiety disorders
    • Apathy
    • Depressive disorders
      Dopamine agonist withdrawals syndrome (DAWS)
    • Dopamine dysregulation syndrome
    • Impulse control disorders
    • Mania 
    • Psychosis
  • Does Parkinson’s disease cause hallucinations?

    Yes, people with Parkinson’s disease often experience hallucinations. While this can be scary to witness, as long as they aren’t disruptive or upsetting to the person, hallucinations are usually harmless.

    Hallucinations are often due to an underlying cause that can be treated, such as an infection or a side effect of medication.

    If a loved one with Parkinson’s disease is prone to hallucinations, try to create a calm, quiet environment with a comfortable temperature and not too much or too little light. You should acknowledge the hallucination, keep the person calm, and try to change the subject. 

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Parkinson's Foundation. Cognitive changes.

  2. University California–San Francisco: Weill Institute for Neurosciences. Parkinson's disease dementia.

  3. Aminian KS, Strafella AP. Affective disorders in Parkinson's disease. Curr Opin Neurol. 2013;26(4):339–44. doi:10.1097/WCO.0b013e328363304c 

  4. University of California–San Francisco: Weill Institute for Neruosciences. Medications and dementia.  

Additional Reading

By Patrick McNamara, PhD
Patrick McNamara, PhD, is an associate professor of neurology and the director of the Evolutionary Neurobehavior Laboratory.