It depends. I suddenly stopped for two months and the only issue was difficulty sleeping for a few days. The depression is due to the lack of THC which your body depends on to feel good. The best medicine for that was riding my bike (literally felt the brain fog melt away during a nice long ride.)
Really, it depends on your life situation and why you use drugs. The root cause for using drugs is always the toughest thing to tackle. After that, quitting is easy. Fixing your life is the HARD part.
Yeah, my and my SO have very different experiences regarding this.
I’ve quit cold turkey several times with little problems - quit for several months or over a year, then used again for x months, then quit again, etc. (This went hand in hand with a certain seasonal job.) Apart from very slight ”I wouldn’t mind a smoke” kind of feelings it doesn’t have much of an effect of me.
My SO was miserable, depressed, craved cigarettes for months and months. For the longest time she was convinced that it isn’t possible for her to quit, since they cravings didn’t go away. (Until they did.)
There's at least some evidence that people have very different affinities to different drugs and their effects and addiction potential are just as individual.
Anecdotally, I can tell you with absolute certainty I could never become an alcoholic, I have no interest in drinking on any two consecutive days and it's usually several month between any alcohol consumption. Yet there have been alcoholics in my family. But when it comes to weed I will be continually stoned out of my mind as long as any weed is available.
It's a terrible side effect of the legal status of most drugs that we have neglected to study most of them to the extend that would be necessary to actually make progress (with the notable exception of tobacco)
Really, it depends on your life situation and why you use drugs. The root cause for using drugs is always the toughest thing to tackle. After that, quitting is easy. Fixing your life is the HARD part.