Our Gemara on the top of Amud Aleph states a powerful idea: Thoughts of transgression are worse than transgression itself, הִרְהוּרֵי עֲבֵירָה קָשׁוּ מֵעֲבֵירָה

Of course, literally and logically sin in action, is much worse. Is it worse to brood for 10 years about killing someone than actually killing someone? Obviously not. So what did our Sages intend? Let us try to understand this from a psychological perspective. 

Returning to the example of brooding and plotting murder for years, intuitively we can understand that a single murderous crime of passion is far worse in terms of damage to the victim. Yet, the person who was brooding and plotting for years, spent years of his or her life in a toxic mental state. This is what the Sages mean when they say that the thought of sin is worse than the sin.

Rav Chaim Volozhin (Nefesh HaChayyim Shaar One:4) notably compares the sin of impure thoughts to Titus’ act of bedding a prostitute in the Holy of Holies. Since one’s intellect is the holiest part of a human and the seat of divine contact with God and the world, the intellect is in ways even more sacred than the physical location of the Temple’s Holy of Holies. 

One of the hallmarks that distinguishes sex addiction from merely impulse control or poor morals is the amount of time spent “cruising” or “mongering”. These terms refer to a state of mind where the addict may spend hours searching for his or her desired fix. This can involve perusing porn sites, prostitution sites or so called “dating” apps. When in this state, the person may ignore personal or familial responsibilities, and endanger himself physically, vocationally or legally depending on the social and financial risks taken. There is a sexual thrill and high that comes from the cruising that may be greater than the act itself. Others may enter a dissociative trance losing track of time and not remembering much of what occurred.

The Sages did not have the label or term addiction, and perhaps the symptom pool and defense structure of ancient consciousness did not express conflicts and drives in identical ways to modern times. But we now can see a certain similarity and insight to this initially perplexing declaration of Chazal.  We see that sometimes, the Addictive Behavior IS the Addiction.