A method for treating a disorder of the central nervous system includes administering to the respiratory tract of a patient a drug which is delivered to the pulmonary system, for instance to the alveoli or the deep lung. The drug is administered at a dose which is at least about two-fold less than the dose required by oral administration. Particles that include the drug can be employed. Preferred particles have a tap density of less than about 0.4 g/cm3. In addition to the medicament, the particles can include other materials such as, for example, phospholipids, amino acids, combinations thereof and others.
