Trading can be addictive, but that is not because it has lot in common with gambling. As a few member have already pointed out, just about anything can become addictive. It's not limited to gambling, and trading, or other money related activities.
Of course, addiction can happen in anything, it isn't only in gambling. I don't refuse the addiction in trading, I said it clearly. However, the addiction in gambling and trading aren't 100% the same. That's the point of my explanation before.
Someone who's addicted to trading isn't necessarily lacking understanding either. Even an expert can get hooked once they slowly lose control over their trading, feel the urge to open positions and chase that rush every time the market gets volatile...
If they understand it, they won't get addiction. People who spent a long time in trading, it doesn't always mean they are expert and understand enough trading. So, it is surely possible that they also can still get addiction in trading.
It's a self control problem, not just a matter of knowledge or experience.
Agree, it isn't only about knowledge and experience but it also can be about self-control (mentality).