The diathesis-stress model's explanation for disorder onset emphasizes:

• A. A vulnerability interacts with a precipitating event to produce the disorder.
• B. Disorder arises solely from genetic factors.
• C. Disorder arises solely from environmental stress.
• D. Disorder is explained by personality alone.

Answer: (A)

A vulnerability interacts with a precipitating event to produce the disorder. The diathesis-stress model holds that people have a predisposition (diathesis)—which can be genetic, biological, or linked to early experiences—yet this alone doesn’t cause the illness. A stressor or triggering event must occur, pushing the individual over a threshold into symptom development. This explains why disorders don’t arise from genes or life stress alone; instead, it’s their interaction that matters: a person with greater vulnerability may develop the disorder after a relatively moderate stressor, while someone with lower vulnerability might not after a similar stressor, and a high-stress situation might not cause illness in someone with little vulnerability.