With your consent, a genetics sample, consisting of three (3) additional blood tubes (totaling approximately six teaspoonfuls) will also be collected for a genetic analysis. The genetics sample will be identified with a subject number that corresponds to your other samples. We will use this sample to determine the genetic sequence of DNA that you have that is responsible for encoding proteins that are responsible for breaking down or transporting medications like lamotrigine so that they can be eliminated from your body. You can choose to participate in the main study without taking part in the genetics portion of the study. If you withdraw from the main study, the genetics sample will be discarded with the rest of the samples. if you choose to participate in the genetics portion of the study, we will store the genetics sample indefinitely, however, no testing other than for specific DNA sequences will be done unless we have contact you and received permission to do so.