My psychiatrist didn't ask me to split doses. Also he asked me to increase the dosage only 25 mg a week. As the rare side effects can be pretty serious I think it is important to follow your psychiatrists instructions.Thank you for your reply. Now I take Lamotrigine 200 mg/day. So can I go to 300 mg/day in split doses? e.g. 200 mg in the morning and 100 mg in the evening?