Are there specific game mechanics that have a high correlation with addictions or with the characteristics of addictive behavior?
Should such mechanics be avoided or can they be used with other checks in place?
This article identifies the key gameplay elements (of Candy Crush Saga) that keep players engaged and excited for the next level. A few key quotes are:
This is essentially enticing a user with a quick reward (e.g. an easy to earn badge) to quickly get them hooked on the idea of earning more.
These could be rewards unlocked as they progress (e.g access to moderator tools on SE).
Relatively self-explanatory, but being compared to other users (particularly friends) can be a major motivator to maintain bragging rights.
This is an important one in terms of addiction; once you've drawn a user in with other methods, it can get to the point where they have to keep going or else feel they have wasted their time. Of course, with gamification there isn't an end level; you want your application to be used indefinitely.
With all the above said, I think the important thing is not what you implement, but rather, how you implement it. Try to avoid badges such as 200 consecutive logins, and use analytics to watch out for any addictive behaviour.
Like drugs, games activate the reward center of the brain, and this in turn releases dopamine, making you feel good. That's what causes any addiction.