<prompt> Which is not a side effect of lamotrigineDiplopiaDizzinessDecreased cognitionRash  <response>: C Decreased cognition Side effectsare sleepiness, dizziness, diplopia, ataxia and vomiting. In some comparative trials lamotrigine has been found to be better tolerated than carbamazepine or phenytoin. Negative effect on cognitive function is not reported. Rash may be a severe reaction requiring withdrawal. 