"If so, are there particular strains or types of products I should look for?"
Cannabis has been known to improve concentration and focus. Many patients have successfully used cannabis to treat symptoms of ADD and ADHD. Keep in mind that this effect is strain and dose specific. Some strains will increase concentration and focus while others strains will interrupt concentration and focus. Sour Diesel is a popular strain used to focus but there are many others available. It is best to keep the dosing low, to about a few milligrams. Marijuana affects everyone differently so strain, dosage and route of administration should be discussed with your provider.