Genetic testing for saliva is a new tool that analyzes certain genes in DNA to determine how quickly a person's body metabolizes certain medications used to treat ADHD. These tests can be expensive and there is still uncertainty about their effectiveness. It is recommended to consult with a pharmacist to analyze the situation in more detail and communicate with a doctor if necessary. If considering genetic testing, it typically takes 1 to 3 weeks from the receipt of the sample for results to be obtained. For a more accurate timeline, it is best to contact the testing company directly.