Q:  Lithium & Feeling Mentally Slow/dull

Dr Phelps,

I have been on a low dose of lithium (625 mg) for about three weeks.  I am feeling mentally slower on the uptake in two areas 1) playing my violin in orchestra concerts  (my profession)   and 2) in writing letters and conversing with others on a more-than-strictly-practical level.

Apart from this side effect, which is disturbing to me, I feel *very* stable and basically cheery.

I have two questions:

Does the effect of feeling mentally slow or dull go away with time?  If so, how much time?

Also, if I should go off lithium and then come back to it later on, will it be as effective in treating my other symptoms?

I am diagnosed with Bipolar 2.

Thanks so much.


Dear Ms. N --

In my experience with lithium, the effect you are describing does not usually go away with time. Sometimes a very small dose reduction can maintain the benefits and diminish that side effect to an acceptable degree. Indeed, sometimes we have to wonder: is the lithium-you closer to the real you? the not-so-accelerated-you? Or is this a side effect? In general, I lean strongly in the direction of assuming that this is a side effect, because it is certainly not one I want to saddle my patients with. They will not tolerate it for long, for one thing. And it can really interfere with quality-of-life, as you describe. However, asking that question (side effect, or therapeutic effect?) is an important one before considering moving on to alternatives.. 

Your second question is also a very important one: if you go off, and then come back, can you count on the benefits you are currently getting still being there on return? Unfortunately, nothing in my business comes with a guarantee. You may have read about lithium being "less effective" when it is restarted after having been discontinued. I think most of that reputation is in association with sudden discontinuation, where we do indeed have several studies showing a very high likelihood of symptom recurrence and subsequent "lithium resistance", at least relative to the response to lithium prior to the stoppage.

Some of that subsequent "lithium resistance" might be a worsening of the illness during the period in which it was not only not controlled, but perhaps quite suddenly made worse by the sudden cessation of lithium.

Therefore, I am much less certain that we need to fear the loss of benefit from lithium in circumstances like yours: low dose, Bipolar II, planned cessation after short duration on the medication. But unfortunately, as I say, there is no guarantee. Perhaps it might be a little reassuring that for patients in your circumstance, a fear that we might not be able to get good symptom control with other strategies, and then not be able to get it either with lithium restarted, would not be a major factor in the decision making process. However, your circumstances might warrant more caution: there could be other variables, such as how many other strategies you had tried before this, that would affect this decision.

Good luck figuring out your next step.


Dr. Phelps