Here is some general information about addiction. Understanding Internet porn addiction means understanding addiction mechanisms. 
All addictions involve hijacking of the same neurocircuitry, and run on the same neurochemicals. A basic physiological principle is that drugs do not create anything new or different; they simply increase or decrease normal brain functions. In essence, we already possess the machinery for addiction (mammalian bonding/love circuitry), and for binging (yummy food, mating season).
Top researchers agree that all addictions involve the same pathways and mechanisms. Here are a few FAQs from renowned addiction researcher Erik Nestler (Nestler Labs).
Q: How can you reverse the changes in your brain?
A: There is no evidence that changes in the brain associated with drug addiction are permanent. Rather, we believe that these changes can be reversed. It can take a long time, often many years. The reversal requires “unlearning” many of the bad habits (compulsions) associated with addiction in general.
Q: Do these changes occur naturally in your brain without the influence of a drug of abuse?
A: It is likely that similar brain changes occur in other pathological conditions which involve the excessive consumption of natural rewards.These include conditions such as pathological over-eating, pathological gambling, sex addictions, and so on.
Q: Are the different types of addictions related? How? (Drugs, gambling, etc)
A: There is increasing evidence from clinical studies that some of the same brain regions (brain reward pathways) are critically involved in mediating drug addictions and the so-called natural addictions.
This section on addiction in general contains both lay articles for the public, and research articles. If you are not an expert in addiction, I suggest starting with the lay articles to get a better understanding of addiction mechanisms. The letter “L” marks which ones they are.
;
