People with bipolar disorder commonly have memory problems. This is actually something I’ve been doing research about as a PhD student at UCLA. Not only that, it’s something I struggle with myself.
There are two main categories of memory problems in bipolar disorder: problems that are associated with a mood episode, and problems that exist outside of mood episodes (during euthymia, or well periods).
During episodes of depression, problems with explicit memory are common. That’s the kind of memory you’re using when you try to recall facts or events — in contrast to implicit memory, which includes emotional learning (conditioning) and procedural learning (like learning how to ride a bicycle). Implicit memory tends to be preserved, but depressed people struggle to explicitly remember things. For example, trying to remember the names of past presidents might become extremely effortful. This is actually the same for unipolar depressives. Controlling for the severity of depression symptoms, bipolar and unipolar depressives are very similar in the area of memory performance (Bearden et al., 2006).
Memory impairments are more pervasive in manic episodes. Research has found that during a manic episode, people perform more poorly at tasks requiring episodic memory (the kind of memory you use when you remember a scene you’ve lived through, typically from a first-person perspective), working memory, spatial attention, and problem solving (Sweeney et al., 2000). Many people who have experienced manic episodes have a great deal of difficulty remembering what happened during the episode. It’s possible that mania disrupts the encoding of new memories (King et al., 2013). For some of us, this is a double-edged sword: it’s painful to remember, and yet it’s painful not to remember. Sometimes we’re left trying to piece together what actually happened while simultaneously part of us is trying to move on from it. Even worse, sometimes other people remember better than you do.
Problems with episodic memory aren’t limited to mania, though.
Various studies have shown bipolar people who are euthymic (not currently having a mood episode) to perform poorly at memory-related tasks. Problems with executive functioning frequently come up — these problems can be similar to people with ADHD. But one of the most noteworthy findings is impairment in episodic memory about one’s own life. In particular, it seems like memory for specific events is impaired, but memory for personal facts (like one’s name or birthday) are not affected (Shimizu et al., 2009).
It’s hard for me to remember a lot of things I’ve lived through. Not infrequently I meet people who tell me we’ve met before, but I have no idea who they are. I have friends that I don’t remember how or where we met. Even memories I’d like to keep seem not to stick very well, which is saddening. I forget most of what happens after a year or two. Sometimes the things I do remember are a little strange. According to my psychiatrist, I have an incredible ability to know exactly how many times she’s told me the same story in the past, but I don’t remember the contexts I heard it in.
One study (King et al., 2013) found that when they asked bipolar disorder patients to recall memories from their life, they were more likely to recall those memories from a third-person or observer perspective. It makes me wonder why that is. It’s like the people with bipolar disorder can’t remember being in their own head, even if they can “see” what happened in their memory. Something is disconnected between their past and present minds. They specifically can’t remember being themselves.
Bipolar disorder can be so much more than having emotional “ups” and “downs”. For some people bipolar disorder affects us every day and changes how we live life. Many people don’t realize how memory problems can affect us. When I write, I write about the present at least as much as I write about the past, because I know how transient the present really is.
Have you ever experienced something like this?
Bearden, C. E., Glahn, D. C., Monkul, E. S., Barrett, J., Najt, P., Villarreal, V., & Soares, J. C. (2006). Patterns of memory impairment in bipolar disorder and unipolar major depression. Psychiatry Research, 142(2–3), 139–150. https://doi.org/10.1016/j.psychres.2005.08.010
King, M. J., Macdougall, A. G., Ferris, S., Herdman, K. A., Bielak, T., Smith, J. R. V, … Mckinnon, M. C. (2013). Impaired episodic memory for events encoded during mania in patients with bipolar disorder. Psychiatry Research, 205(3), 213–219. https://doi.org/10.1016/j.psychres.2012.08.005
Shimizu, M., Kubota, Y., Mason, R., Baba, H., Calabrese, J. R., & Toichi, M. (2009). Selective Deficit of Autobiographical Incident Memory in Subjects with Bipolar Disorder. Psychopathology, 42, 318–324. https://doi.org/10.1159/000232974
Sweeney, J. A., Kmiec, J. A., & Kupfer, D. J. (2000). Neuropsychologic impairments in bipolar and unipolar mood disorders on the CANTAB neurocognitive battery. Biological Psychiatry, 48(7), 674–684. https://doi.org/10.1016/S0006-3223(00)00910-0