Questions re. BP and Cognitive Deficits
Dear Dr. Phelps,
I am being
treated for bipolar with Lexapro, lamictal and recently, risperdal. I recently
became aware of the connection between bipolar illness and cognitive deficits. I
have been aware of some deficits in the past and am aware that the "blips" seem
to be getting worse. Some of them are a delay in processing information,
inability to connect certain concepts, and when under alot of stress i have
trouble with word retrieval or mix up words and I forget conversations that
involved tasks that I am supposed to follow up on. This happens at work and is
a problem. I wanted to know two things:
1. Do you
think Risperidone may make cognitive deficits worse? and
2. Can you
give me an idea what tasks are associated with the problems I mentioned above,
apart from the testing tasks described below.
up studies on PubMed and am included some of the results here in case it's of
interest) I don't understand what tasks are associated with the deficits.
[J’s list of study results appears just after my reply
below – Dr. Phelps]
all your work in the area of Bipolar illness!!
Dear J’ --
Your question illustrates a very, very common problem: When people with bipolar
disorder are having problems with memory, and intellectual function generally,
is the problem coming from the illness, or from the treatment -- or both?
As you can imagine, separating these two potential
causes is tricky. We know that the illness itself can cause very substantial
trouble with memory, and other kinds of intellectual processes (often lumped as
"cognitive impairment"). On the other hand, as one of my colleagues says,
"medications are guilty until proven innocent". Particularly if some worsening
of cognitive function seemed to follow quickly after a new medication was
introduced, that medication has to be suspected as a culprit.
So far, therefore, we are suspecting the illness
itself or medication generally. In your case, we have to add two more potential
causes of cognitive impairment. First, Lamictal (lamotrigine) has been very
clearly associated with difficulty finding words. This is much more a problem
that higher doses, like 400 mg and is relatively uncommon at the typical target
dose of 200 mg. But it is so well recognized, and you mentioned that problem
specifically, so Lamictal has to be suspected for playing a role in at least
this particular aspect of the problems you describe. Not that we could be
certain it is the culprit, but it must be suspected.
Finally, the fourth potential cause of cognitive
impairment which should be considered in trying to sort out what is going on
with your intellectual function, is the potential for an antidepressant (Lexapro/escitalopram,
in this case) to -- in some degree, from zero to a lot – cause a “mixed state”.
Recall that mixed states are combinations of manic and depressed symptoms
occurring at the same time. In the view of most experts, antidepressants can
bring on mixed states (although this is not firmly established).
The point here is that mixed states can cause anxiety
and agitation, which can interfere with cognitive ability (note study # 4 below,
in particular). In the story you describe, it would be difficult to determine
to what degree, if any, Lexapro was contributing to the problem through this
mechanism. However, when you first begin to look at potential culprits, lining
them up to decide which ones to investigate most thoroughly, and in what order,
in my opinion this is one more culprit to place in the line.
Having lined them all up, you then have to decide how
much you are willing to go through to identify the role that each of the
potential medication culprits might be playing. As you systematically remove
one medication at a time, by tapering it carefully (*further comment below), you
are obviously at risk of getting worse if that medication was actually doing
something useful. Ironically, it can be doing something useful and interfering
with your cognitive ability at the same time, so this whole evaluation can be
tricky. Meanwhile, you will be aware all the while that, at the end of your
investigations, you may conclude that the primary culprit is the illness
*Obviously, in determining how to approach all of
this, you'll have to discuss your options very carefully and thoroughly with
your psychiatrist. I hope it is obvious: you should never take any steps, and
figuring out something like this, on your own.
One more thought: study # 5 below correlates
antipsychotic treatment with cognitive impairment. However, in a correlation
like this, you can't tell if people with more severe illness, who require
ongoing antipsychotic treatment, have more memory and IQ decreases because of
the antipsychotic -- or because they have a more severe illness.
Instead, the easiest way to tell when a particular
medication might be the basis for decreases in intellectual function is to have
noticed dramatic decreases in cognitive ability shortly after the medication was
introduced. In the absence of such an observation, in my experience, it is far
more likely to end up concluding that the illness is the problem, not the
medication -- even when we try to establish that for sure by tapering off some
As you can see, this is quite a complex process. Good
luck with that.
[The following studies were included in Ms. J’s
question. They illustrate that problems with cognitive function such as memory
and decision-making are associated with bipolar illness itself, but medications
are implicated as well.]
Significant deficits in spatial working memory, visual sequencing and scanning,
verbal fluency and abstract problem solving, particularly when a memory
component was involved. In spatial delayed response tasks, performance suggested
deficits in short-term memory encoding and/or storage, rather than capacity
limitations in spatial working memory. Earlier age at onset of illness and
antipsychotic medication usage were associated with poorer performance on
speeded information-processing tasks.
Psychotic bipolar disorder was associated with differential impairment on tasks
requiring frontal/executive processing, suggesting that psychotic symptoms may
have correlates partially independent of those in bipolar I disorder generally;
deficits in attention, psycho-motor speed, and memory appear to be part of the
broader bipolar disorder deficits.
Psychosocial functioning was impaired for all groups, but a correlation
significantly with neuro-psychological performance occurred in depressed and
The mixed/manic bipolar patients demonstrated robust deficits in episodic and
working memory, spatial attention, and problem solving. In contrast, depressed
bipolar and nonbipolar patients had impairments only in episodic memory.
Current antipsychotic meds, duration of illness, and family history of affective
disorder were the most significant predictors of IQ and memory function in BD I.
Published April, 2008