It's addictive in the sense of what is causing you to consume it. The condition is referred to as pica, the eating of nonfood substances. Baby or talcum powder are dangerous in the sense that they can be easily ingested into the lungs causing respiratory problems, sometimes pneumonia. It would be advisable to consult a physician to determine the cause of your ailment.
I think it is addictive cause I started eating it every sense my 10th grade year of school and now I'm a senior. The only kind I eat is Wal*Marts Brand which is Equate Mild Baby Powder, OMG I love it with a passion. The only thing is that I think it might hurt me with my breathing cause i breathe heavier,but it's so addictive that I can't stop at the moment.