Medications used to treat psychiatric disorders are commonly referred to as psychotropic drugs. These drugs are commonly described by their major clinical application, for example, antidepressants, antipsychotics, mood stabilizers, anxiolytics, hypnotics, cognitive enhancers, and stimulants. A problem with this approach is that these drugs have multiple indicators. For example, selective serotonin reuptake inhibitors (SSRls) are both antidepressants and anxiolytics, and the serotonin-dopamine antagonists (SDAs) are both anxiolytics and mood stabilizers.