The present invention discloses a method of treating agitation or the signs of agitation in a subject comprising the sublingual administration of an effective amount of an alpha-2 adrenergic agonist, more particularly Dexmedetomidine, or a pharmaceutically acceptable salt thereof. The method is particularly suitable for the treatment of agitation associated with neurodegenerative and/or neuropsychiatric diseases. The present invention also discloses the sublingual administration of an alpha-2 adrenergic agonist, more particularly Dexmedetomidine or a pharmaceutically acceptable salt thereof at a dose that is effective to treat agitation or the signs of agitation in a subject, but does not cause significant sedation.
