I read somewhere that apparently dropping acid once can bring out mental illness’ such as depression etc is this true?
There is no reliable scientific evidence out there on this topic due to the illegality of most proposed psychedelic research, but some users do caution against taking psychedelics if you have a family history of mental illness (especially schizophrenia). Psychedelics affect each consciousness differently depending on your unique personality and background, and it is definitely a good thing that you are doing research before trying them.
As far as depression is concerned, psychedelic use has only had positive effects on my mental health and cognitive ability in general. But, to experience these benefits you need to have the experience within the proper set and setting. I’ll refer you to the article in the first issue of the HE magazine (can’t remember the name) for an excellent, more detailed guide that could not realistically fit into this thread.
Also, a word of caution: psychedelics MUST be respected. It is nothing like smoking cannabis or drinking alcohol. Take a comfortable dose, limit the frequency of your use (extremely important for brain chemistry) and they can bring you great things.