- Catatonic disorders
- Chamomile
- Child Depression Inventory
- Childhood disintegrative disorder
- Children's Apperception Test
- Chloral hydrate
- Chlordiazepoxide
- Chlorpromazine
- Circadian rhythm sleep disorder
- Citalopram
- Clinical Assessment Scales for the Elderly
- Clomipramine
- Clonazepam
- Clonidine
- Clorazepate
- Clozapine
- Cocaine and related disorders
- Cognistat
- Cognitive problem-solving skills training
- Cognitive remediation
- Cognitive retraining
- Cognitive-behavioral therapy
- Communication skills and disorders
- Community mental health
- Compliance
- Compulsion
- Computed tomography
- Conduct disorder
- Conners' Rating Scales-Revised
- Conversion disorder
