Yeah. I put this in, due to popular demand, a mutagen-pack or two ago.
FWIW the addiction is primarily psychological. Anything that adds (or removes!) traits has 2 * the amount of traits it can handle addiction power. IIRC, if you roll less than the addiction power on a d100, take a level of addiction.
Addictions only become noticeable at level 3.
FWIW there’s a trait that specifically exists to amp up the effects of mutagen addiction.
Purifier is more addictive than mutagen. Serums are worse. 