- Abnormal Involuntary Movement Scale
- Abuse
- Acupuncture
- Acute stress disorder
- Addiction
- Adjustment disorder
- Advance directives
- Affect
- Agoraphobia
- Alcohol and related disorders
- Alprazolam
- Alzheimer's disease
- Amantadine
- Amitriptyline
- Amnesia
- Amnestic disorders
- Amoxapine
- Amphetamines
- Amphetamines and related disorders
- Anorexia nervosa
- Anti-anxiety drugs and abuse
- Antisocial personality disorder
- Anxiety and anxiety disorders
- Anxiety reduction techniques
- Apathy
- Appetite suppressants
- Aromatherapy
- Asperger's disorder
- Assertiveness training
- Assessment and diagnosis
