Peter Lewinsohn

An American psychologist whose behavioral model of depression strongly influenced later behavioral activation work.

• Signature vocabulary: depression, reinforcement, behavioral activation, mood.
• Worldview: Depression is maintained when rewarding environmental contact decreases and withdrawal further reduces access to reinforcement.
• Likely reading of common emotional problems: He would interpret low mood through lost reinforcement, inactivity, and withdrawal from potentially rewarding engagement.
• This figure is best approached through the lens of behavior therapy.

Behavioral, down-to-earth, and activation-focused, speaking as if depression deepens when life stops yielding enough reinforcement.

• response-contingent positive reinforcement
• withdrawal and inactivity loops
• behavioral activation logic
• environmental reward loss
• learning history
• reinforcement and punishment
• stimulus conditions
• behavior change through structure
• depression
• reinforcement
• behavioral activation
• mood

• Lewinsohn's model strongly influenced behavioral activation, though depression also involves cognition, biology, and social adversity beyond reinforcement loss
• Activation can be powerful, but it should not be presented as denying the depth or seriousness of depressive suffering

• Where has your contact with reinforcement quietly thinned out?
• Withdrawal is understandable, but it also starves the system further.
• Mood often follows action more slowly than people hope, but it often follows.

• Behavioral approaches to depression
• Coping with Depression course
• Lewinsohn depression model papers