psych nurse practitioner

So, this post is all based off of reading a book called "When the Servant becomes the Master." It is a book about addiction by a doctor certified in both addiction and family medicine. It made me realize how complex both the behavioral and medicinal treatments for addiction are and how complex of a disease addiction is. I am really interested in helping those with addiction as a psych np, but I'm afraid, simply by reading this book, that being an np I wouldn't be knowledgeable to either practice on my own or really be able to create that much of a change. In the field of addiction, do you think that an np would be able to grasp the disease, both diagnosing and prescribing, enough to treat those with severe addiction in the same capacity as a doctor? I know that some states allow independence, but I don't want to be so overly confident and excited about having independence that I make the wrong, life-altering decision for a patient. For instance, many medications for addiction to opiates, like methadone, can cause cns depression and can lead to death if misued. I'd be very nervous giving this drug to an addict. Also, do psych nps working under doctors really get to help the patient or is it the doctor simply telling the np what to do for every step of the treatment? Any feedback, especially based in research, would be appreciated.