I'm speaking within the framework of what is sensible, given the science. If you want the trip to have more lasting effect then according to the research you should have someone guiding you along. It kinda makes sense too. You can spend a trip looking at butterflies and admiring them taking with you from the experience a certain wonder for the beauty of nature. It might even help you with your depression somewhat but will not substitute professional guidance that will help you confront what is an underlying psychological issue actually causing the depression.