You can only be physically addicted to certain substances but you can be mentally addicted to anything.
You mean, you haven’t met someone with a mental addiction yet.
But — you are technically correct, indeed.
In ICD 10 the disorders that are commonly regarded as mental addictions are classified not as addiction, but as eating disorders, habit and impulse disorders and disorders of sexual preference. Don’t know whether I missed any.
BTW, Substance-related addiction is classified as mental and behaviour disorder due to psychoactive use. So, technically, “addiction” does not exist at all.
I’ve met people with behavioural disorders, sure, but not “mental addictions”, since an addiction requires a physical component.
I think you can broadly say that a genuine addiction starts because it’s pleasant, and then continues because stopping causes you to actively feel bad. E.g., you keep smoking because the withdrawal from nicotine is pretty shitty, and takes a week or so to get past (although the behavioural component to the addiction can take weeks or months). Masturbation and porn use doesn’t fall into that model at all; the consequences of not masturbating is that you don’t feel something pleasant, not that things start hurting.
It’s simply not in the same category as alcoholism, or addiction to nicotine, opiates, etc. People that call it that do so for for moral reasons, not because it’s a legitimate medical issue. If you speak to a psychologist that is trained in and specializes in sexual disorders–again, not one that’s using a religious/spiritual approach, but one that’s evidence-based–you are unlikely to find anyone that regards it as a legitimate disorder unless you’re doing things like masturbating at your desk at work 3-4 times/day, or needing to pull your car over on the way to work to compulsively masturbate.