Have there been any scientific studies done that prove negative and hostile environments can affect how quickly our bodies are able to heal?

A recent report from Ohio State University evaluated whether or not emotional stress affected healing. Forty-two married couples participated in the research project in which they received small blisters on their skin (ouch!) and then engaged in either a loving, supportive conversation or an angry, hostile disagreement. The researchers measured the concentration of immunological chemicals in the blood and tracked how long it took for the wounds to heal. The results showed that one hostile interaction slowed healing by almost twenty-four hours. In other studies, medical scientists have demonstrated that in addition to high blood pressure, high cholesterol and smoking, hostility is an independent risk factor for heart attacks.