Often referred to as the "common cold of mental health," depression causes about 8 million doctors' appointments a year. More than half are with primary care physicians. A new study suggests those doctors may not be the best to treat the condition due to insurance issues, time constraints and other factors. The paper, published Monday in the March issue of Health Affairs, examines how primary care doctors treat depression. More often than not, according to the study, primary care practices fall short in teaching patients about managing their care and following up regularly to track their progress. That approach is considered most effective for treating chronic illnesses.