The functional definition of "addiction" is any substance (drugs, alcohol) or activity (sex, gambling) that has a negative impact on any of the following: Liver, lover, livelihood or the law.
If your C.R. activities harm your health ("liver") or cause problems with a spouse ("lover), if you're going into debt or risking loss of your job ("livelihood") or if you get caught stealing/embezzling to get the money you need to get to C.R. (the law"), you have a problem. All kidding aside. I in fact have pissed off my S.O. and have gone into debt to get down to San Jose to partake. I guess that means that functionally, I have a C.R. addiction.
OTOH, if you're just way into it, enthusiastic about your trips etc. it might just be a habit.

Aside from the four L's above, ask yourself the following:
1. Does post-trip depression/longing cause loss of sleep, appetite or causes mood changes?
2. Are you having trouble sleeping? BTW, this may be because of a persistent hard-on, which leaves no extra skin for eyelids...thus the eyes stay wide open.
3. Do you find yourself keying in on Spanish conversations around you? Do you watch Telemundo or Univision even if you don't speak Spanish, just to see some latina cleavage?
4. Have you renamed your savings account "my Costa Rica fund?"
5. Do you visit CRT, Club Hombre or any other mongering sites more than once per day?
6. Do you buy clothing with C.R. trips in mind, rather than choosing clothing suitable for your work?
7. Do you secretly envy Pacifica55, Bang Bang 57, BKTuna, Chi Trekker, LivinCR or any of the other guys who are now residents of SJ? More importantly, are you buying voodoo dolls of these gentlemen and then sticking the pins....well, you know where?
8. Have you added rice and black beans to your diet? Rice and red beans? Ceviche? Salsa Lisano?
9. Do gringas suddenly appear as hallucinations of flesh-colored Barney the Dinosaur? Or worse, Fred Flintstone? Or worse, Hilary Clinton?
10. Have you decided that the smells of high-sulphur diesel fuel and good cigars are very pleasant smells when inhaled in combination with cheap perfume?
If the answer to any of the Four L. questions, or any of the ten other points above is "yes," you may have a problem.
The only cure for this addiction is either castration (rather extreme, don't you think?) or better, buying a ticket back to C.R. as quickly as is humanly possible!
