We present a structural equation model of the way in which personality factors may modify the response to changes in life situation, based on two-wave panel data from a random sample of 296 Dutch adults. Three definitions of vulnerability were studied: high neuroticism (N), low self-esteem (SE), and an external locus of control (LC). The multigroup LISREL analysis led to the following conclusions: First, previous symptom level was strongly related to current symptom level. The strength of this relationship was independent of SE and LC but modified by N. Secondly, the impact of life situation changes on distress level was moderately strong and similar to what others have reported. Thirdly, a marked modifier effect was found for neuroticism; responsiveness significantly increased with N level. For SE and LC we observed reduced responsiveness among low vulnerability subjects, but the differences did not reach statistical significance. The implications of the findings are discussed.