 Patients who did not become seizure free on valproate will be identified by neurologists in the participating hospitals. When these patients are willing to participate, they are randomized to one of three drugs: carbamazepine, lamotrigine and levetiracetam. In phase 1 of the project they keep on using valproate. The randomized second-line drugs will be titrated to a first dose level and the effectiveness of the combinations will be evaluated. When seizures persist and adverse effects allow it, the add-on drug is titrated to a second dose level and again the effectiveness of the combination is evaluated. When seizures still continue and adverse effects allow it, the add-on drug is titrated to a third and final dose level. When a patient does not become seizure free on a combination on that final level or adverse effects have prevented a dose increase to a higher level, that combination has failed in phase 1. When the patients does become seizure free on his or her combination, the combination is deemed a success for that patient. A patient will proceed to phase 2, when he or she has at least experienced a 50 seizure reduction. 