- Speech-language pathology
- St. John's wort
- Stanford-Binet Intelligence Scale
- Stereotypic movement disorder
- Stigma
- Stress
- Stroke
- Stuttering
- Substance abuse and related disorders
- Substance Abuse Subtle Screening Inventory
- Substance-induced anxiety disorder
- Substance-induced psychotic disorder
- Suicide
- Support groups
- Systematic desensitization
