Lamictal has the possibility of causing cognitive deficits as a side effect. What is thoroughly understood to lead to cognitive deficits is excessive drinking, insufficient sleep, poor diet, lack of exercise, and destabilizing into mania or depression - such actions lead to the atrophy or physical damage of brain cells, even neuronal cell death and neurodegeneration. Medications like Lamictal are known to be neuroprotective.

So, before you decide to go off your mood stabilizer I think it would be prudent to be completely honest about which things most affect your intellectual capacities.

Furthermore, withdrawal from psychotropics can be extremely difficult for some individuals to the point of being completely disabling both physically and mentally. If you were to discontinue Lamictal it would be critical to stop drinking during the withdrawal period (which when safely done requires months). Failure to do so increases the risk of neuronal cell death.

I really think you need to have a detailed discussion about this with your pdoc, however unpleasant that may be.