I'm age 63. This subject interested me so much I had to revisit memory loss. I have same problems. I can't recall what I just read, but maybe this will, or will not help. SEARCH: GOOGLE - Do Bipolar Medications Help Memory? Two different sites that came up first:

Bipolar and Memory Loss - Does this sound like you?
Listed here are:
1. Bipolar and the loss of semantic.
2. Loss of sensory memory and bipolar.
3. Procedural memory loss and bipolar disorder.
4. Problems with working memory in bipolar.
5. Long term memory loss and bipolar.

Other sight:
Bipolar Disorder and Memory Loss - Every day health.
Mania - studies have shown that memory and cogniton problems are at their worst during manic episodes. Patients operating at high speeds due to mania have hard time encoding new info into their memories, and also show difficulty accessing memories.
Depression - Other studies show that depressive phases also can create problems with memory. When your mind is preoccupied with negative thoughts about yourself, your world, your future, you aren't as able to concentrate and (be) in the moment.
Also when bipolar patients who are between mood swings also have memory problems and other cognitive deficits. So on and so on ----------------

What I thought I heard, or read, true or not, medications would help delay the brains damage from memory.