Alzheimer’s Disease is a Disorder of Consciousness

Abstract

The diagnostic criteria for Alzheimer’s disease (AD) described in DSM-5-TR, require a decline in memory and learning and in at least one other cognitive domain among six cognitive domains, and also interference with the activities of daily living (ADL) because of decline in these cognitive functions; as such, DSM-5-TR positions memory impairment as the core symptom of AD. DSM-5-TR shows the following examples of symptoms or observations regarding impairments in everyday activities in terms of learning and memory involving the six cognitive domains. Mild: Has difficulty recalling recent events, and relies increasingly on list making or calendar. Major: Repeats self in conversation, often within the same conversation. These examples of symptoms/observations demonstrate difficulties in recall, or difficulties in bringing memories into the consciousness. In the article, it is proposed that considering AD as a disorder of consciousness could promote a better understanding of the symptoms experienced by AD patients and contribute to devising methods to provide improved care to these patients.

As many people involved in the care of Alzheimer’s disease (AD) patients are aware, the symptoms that manifest in the daily lives of AD patients cannot merely be explained by cognitive decline, such as memory impairment, per se. In the article, it is proposed that considering AD as a disorder of consciousness could promote a better understanding of the symptoms experienced by AD patients and contribute to devising methods to provide improved care to these patients, through the diagnostic criteria and examples of symptoms or observations of AD described in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR).

The DSM-5 TR diagnostic criteria for AD (American Psychiatric Association, 2022) require a decline in memory and learning and in at least one other cognitive domain (six domains in total: complex attention, executive function, learning and memory, language, perceptual-motor, and social cognition) and also interference with the activities of daily living (ADL) (instrumental activities of daily living or basic activities of daily living) because of decline in these cognitive functions; as such, DSM-5-TR positions memory impairment as the core symptom of AD. However, memory impairment alone does not severely interfere with the ADL. There are people who cannot remember things from a few minutes ago due to severe memory impairment resulting from head injury or as a sequela of a cerebrovascular accident; however, these people can raise children, do household chores, take trains and buses, drive a car, do groceries using aids such as frequent jotting of notes, and manage their lives. In other words, these people can manage their daily lives as long as they are aware of their memory impairment. It is common for AD patients to have delusions of theft, such as falsely believing that his/her money has been stolen by looking at his/her bankbook, forgetting that the person himself/herself withdrew the money. If the person is aware that he/she has memory impairment, he/she can record the date, time and amount of the money withdrawal in a notebook, to avoid the delusion of theft. A disruption of self-awareness or consciousness of one’s own condition in which the cognitive functions have declined (self-consciousness) forms the basis of the impairment of the ADL in these patients.

The followings are examples of symptoms or observations regarding impairments in everyday activities in terms of learning and memory involving the six cognitive domains described in the DSM-5-TR criteria (American Psychiatric Association, 2022).

Mild: Has difficulty recalling recent events, and relies increasingly on list making or calendar. Needs occasional reminders or re-reading to keep track of characters in a movie or novel. Occasionally may repeat self over a few weeks to the same person. Loses track of whether bills have already been paid.

Major: Repeats self in conversation, often within the same conversation. Cannot keep track of short lists of items when shopping or of plans for the day. Requires frequent reminders to orient to task at hand.

Memories are memories as long as they remain in a latent state, and when a memory is recalled and brought into consciousness, it is no longer a memory, but a consciousness (Ohigashi, 2011). In other words, the symptoms/observations in the DSM-5-TR criteria are symptoms/observations from the standpoint of difficulties in recalling and keeping track, and are examples of difficulties of bringing memories into consciousness. More specifically, the mild stage is defined as “Has poor awareness about recent events, but his/her awareness of recent events can be improved with the aid of a list or through reminders noted on a calendar. Needs occasional reminders or re-reading to keep aware of characters in a movie or novel. Occasionally may repeat himself/herself within a few weeks to the same person, without being aware of it. Is unaware of whether bills have already been paid.” To sum up, the mild stage of AD is a stage where disruption of self-consciousness has become clear and therefore the affected individual needs to be encouraged to have awareness, which is an important element of the conscious process, using reminders, so that the individual can become conscious of daily experiences. In the severe stage of the disease, the patient is unaware of repeating himself/herself during conversations, often within the same conversation. Is not aware of short lists of items when shopping, or plans for the day. Requires frequent reminders to direct awareness toward the task at hand. To sum up, the severe stage of AD is a stage where the disruption of self-consciousness has become severe and therefore the affected individual needs to be encouraged to have awareness, using frequent reminders, so that the individual can become conscious of daily experiences.

The examples of symptoms or observations regarding executive function in the six cognitive domains in AD patients show that AD patients get exhausted when they have to continue working on activities that require extra effort. This is because AD is a disorder of consciousness; AD patients get exhausted if intense focus is required. Severe AD patients may develop the mirror sign, which refers to interaction with one’s own mirrored self-image in the mirror as another person. This reflects a state of considerably advanced disruption of self-consciousness. Even in patients with severe AD with such advanced disruption of self-consciousness, use of reminders, such as written notes or symbols, is effective. The effectiveness of reminders has been reported, such as drawing way-finding arrows with letters spelling the word “toilet” on the floor to indicate the direction of the toilet (Namazi & Johnson, 1991), placing a photo from a patient’s youth on the front door of his/her room at eye level (Nolan et al., 2002), and marking the inside of the sleeve into which the arm is inserted (Alzheimer’s Society, 2022). The above-mentioned symptoms or observations regarding learning and memory in the six cognitive domains indicate the necessity to use reminders to encourage the patients to have awareness, and in these three examples shown here also, reminders were used to connect perception with movement. More specifically, when the patient looked at the letters spelling the word “toilet” and the way-finding arrows directed to the toilet, his/her action to move toward the toilet was induced; when the patient looked at a photo from his/her youth, his/her action to enter his/her room was induced; when the patient looked at the marked sleeve into which the arm is inserted, his/her action to put the arm into the hole was induced. Awareness is an important element of the conscious process, and reminders allow patients to become aware, leading to the induction of an action. The letters spelling the word “toilet” and the way-finding arrows directed to the toilet did not remind the patient of the location of the toilet; the photo from his/her youth did not remind the patient of younger days’ memories; the marked sleeve into which the arm is inserted did not remind the patient of where to insert his/her arm.

When AD is considered as a disorder of memory, it is difficult to conceive of better methods of care. On the other hand, if it were considered as a disorder of consciousness, methods to provide improved care seem easy to conceive. The behavioral and psychological symptoms of dementia (BPSD), including delusions, agitation, aggression, disinhibition, irritability, aberrant motor activity, wandering and apathy, especially impose a great burden on caregivers. According to a recent systematic review, the fundamental obstacle to caring for patients with BPSD by family caregivers is not memory disorder, but the loss of personhood associated with declining self-consciousness (Feast et al., 2016). Bryden (2012), who was diagnosed as having AD, stated that “Maybe, it’s cancer, and if I do not get it treated, I could die as ‘me’.” Thus, she was afraid of losing her personhood more than her actual death. Both the patient and family understand that AD is a disease of consciousness. However, professionals still do not fully understand it. The diagnostic criteria list consciousness disturbance as an important component of delirium, but not of dementia. Huntley et al. (2021) have reported that this fact clearly demonstrates the lack of understanding that AD is a disorder of consciousness.

Conclusions

Considering AD as a disorder of consciousness could promote a better understanding of the symptoms experienced by AD patients and contribute to devising methods to provide improved care to these patients. To provide improved care for AD patients, caregivers can use reminders that induce actions, in order to encourage AD patients to become aware of themselves.