Sensitization

Sensitization is the process by which repeated exposure to a stimulus or stressor leads to increased responsiveness over time. In sensitized systems, smaller triggers can produce stronger emotional, biological, or behavioral reactions than they would have previously. This concept helps explain why individuals may become more reactive to stress or activating events after repeated episodes of exposure. In bipolar and mood research, sensitization is hypothesized to contribute to increased vulnerability to mood episodes. Repeated mood activation or stress may heighten system reactivity, potentially lowering the threshold for future episodes. Sensitization doesn’t imply inevitability or character weakness; it describes a change in responsiveness within biological and psychological systems. Also see Biological Regulation Systems and Reward Hypersensitivity Model