<qa>  What is the maximum daily time devoted to the study?Volunteers in this project will have their normal daily activities interrupted twice per day. However, each interruption for an EMA response should take only 3-5 minutes. One purpose of this study is to find out if this is too high of a burden for this population. The maximum total daily time devoted to the study should be a no more than 15 to 20 minutes, even with event-generated responses. Each weekly visit should take about 30 minutes, not including time spent in the waiting room. 