Should investors consider buying Walgreens at current depressed levels?It's been a difficult year for Walgreens Boots Alliance (WBA -0.64%), with the stock down about 60% during the past 12 months. The question for investors is whether this is a great buying opportunity or if there is more downside ahead.Let's take a closer look at why Walgreens stock has struggled and what the company can do to turn itself around.Reimbursement pressures and a poor acquisitionThe single biggest issue facing Walgreens is dru ...