Research has shown that people with bipolar disorder tend to have more problems with cognitive functioning than our healthy counterparts. Up to 60% of people with bipolar disorder show problems with cognitive functioning even between episodes. This includes problems with attention, critical thinking, decision making, social skills, some motor skills and memory. Studies of memory and bipolar disorder typically focus on retrospective memory (remembering what has already happened). A new review looks at studies regarding bipolar disorder and prospective memory, that is remembering what to do in the future.
Getting through the day requires a fair amount of prospective memory. You need it to remember to do something later like finish a project, walk the dog, close the refrigerator door and, very importantly, take your medication.
There are two types of prospective memory- time based and event based. Time-based prospective memory involves remembering to perform a specific action at a certain time. Examples of this could be remembering to pick a child up from school or going to a doctor’s appointment. Event-based prospective memory happens when you remember to complete an action when reminded by something in your environment. An example could be remembering to buy a certain item when you see it at the store.
Prospective memory happens in four steps:
1 Encoding an intention (telling yourself you need to remember to do something later)
2 Retaining the information
3 Executing the intention (actually performing the task)
4 Evaluating the outcome
A group of researchers, led by Fu-Chun Zhou of the Department of Psychiatry, Beijing Anding Hospital, looked at a total of four high-quality studies to determine whether or not prospective memory might be affected by bipolar disorder.
They found that in both time-based and event-based prospective memory, healthy controls performed better than those with bipolar disorder. Problems with time-based prospective memory were more common than with event-based in those with bipolar disorder. The authors hypothesized that this might be the case because there are no external cues for time-based prospective memory, meaning the person is relying entirely on their memory to perform a task instead of getting a clue from their environment as happens in event-based prospective memory.
Symptom severity seemed to make a difference in memory impairment. So, the more severe a person’s symptoms of bipolar disorder, the more likely they were to have problems with prospective memory.
While this review of the literature available on prospective memory in bipolar disorder is helpful, it should be pointed out that there were not many high-quality studies available to examine. So, while there is some evidence that prospective memory can be affected by bipolar disorder, the research is not definite. More research is needed to see whether or not the results of these four studies can be considered conclusive.
Image credit: Alice Popkorn