It depends on what the treatment is for.  IRS Pub. 502 states that:

Medical expenses are the costs of diagnosis, cure, mitigation, treatment, or prevention of disease, and the costs for treatments affecting any part or function of the body. These expenses include payments for legal medical services rendered by physicians, surgeons, dentists, and other medical practitioners . They include the costs of equipment, supplies, and diagnostic devices needed for these purposes. Medical care expenses must be primarily to alleviate or prevent a physical or mental defect or illness. They don't include expenses that are merely beneficial to general health, such as vitamins or a vacation.

• Stop Smoking - You can include in medical expenses amounts you pay for a program to stop smoking. However, you can't include medical expenses amounts you pay for drugs that don't require a prescription, such as nicotine gum or patches, that are designed to help stop smoking

• Lose weight - You can include in medical expenses amounts you pay to lose weight if it is a treatment for a specific disease diagnosed by a physician (such as obesity, hypertension, or heart disease). This includes fees you pay for membership in a weight reduction group as well as fees for attendance at periodic meetings.