1. Shelves dedicated to anime or manga
All anime Junkies have one thing in common where they sit there with a wall dedicated full of anime and/or Manga. Ranging from the movies, the complete series of an anime and or all of the novels to their favorite animes. The same can be said about anime based video games as well. For example, I have a bookshelf dedicated to the fairy tail manga series.
2. Novelties and Nicknacks
You maybe a junkie if you have toys, pillows (and I'm talking about body length), jewelry, posters and other forms of material goodies. These material item takes up majority of your room. When Someone walks into the room it looks and feel like they just step into Japan. With useless figures, to the life size cutout of Hastune Miku on your wall. Having too much material possessions is a true sign of anime addiction.
3. Cosplay
Another sign of anime addicts consist of cosplaying. That art of cosplay is to dress up and act like your favorite fictional character from any source of creative outlet. (I.E. from books, movie, games etc...). People doing cosplay are showing their addiction in the form of dress up. I am talking about hand made costumes and not the ones found at party city or purchased online.
4. Being an otaku in public
Have you ever been to a grocery store with friends. And you start making anime reference. Have you ever did the "thousand year of death" on a stranger. Then you might be a junkie. Also, if your mad and your scream "BAKA"! Then start screaming random words in Japanese. Then you might be a addict.
5. Singing the theme song
Do you know the words to the theme song of your favorite anime to the point where you don't need the subtitles? Do you find yourself singing this theme song in the shower do you find yourself singing this theme song in the shower or washing dishes? When your parents aren't home and you put this theme song on full volume? Also, do you find yourself knowing the dance moves and dance like no one is looking? If you have said yes to any of these questions then these are tell tale signs that you are addicted to anime.
6. Going to conventions
Lastly, have you been to a convention like Comi-con, Otaku-con or any convention where people usually cosplay. I am talking about more than 3 times. Have bought VIP passes. Then, yeah, you might need rehab.