My .02
Any regular use of any mood altering substance will cause dependency. Unfortunately there's no such thing as a "Non-addictive" dose of drug. If you are concerned about addiction it's best to stay away from any substances considered addictive especially since you've had past experience battling addiction.
I hear what you're saying that any mood altering substance will cause dependency, but not all cause addiction. Addiction to me is when the drug is mentally addictive. I regard dependency as experiencing withdrawals when you suddenly stop taking the drug. Anti-depressants are non-addictive, but they do make you dependent, as if you stop taking it, you're going to feel withdrawals. Reason for saying is this so you can see the point of view I'm coming from.
With a history of opioid addiction (I'm on buprenorphine now...12 mgs/day), I've been incredibly careful about not taking my prescribed-for-anxiety Ativan more than 1-2 mg every other day. Even with those low dosages, however, am I at risk of physical dependence? I haven't been able to find any studies about the minimum dosage/frequency needed for addiction. I'm certainly not psychologically addicted the way I've been to opioids and cocaine (thinking about it all the time, trying to come up with excuses to use it, etc). I do get anxiety 2-3x/week, though, and I think I've noticed some muscle cramping and other possible withdrawal-type symptoms if I go 3 or 4 days without. Is this possible? Any input would be appreciated.
There is no minimum dose as everyone is different. How many weeks have you been taking?
To regard the OP's question about a non-addictive dose of Ativan; there is no non-addictive dose of Ativan. Ativan can be mentally addictive, meaning that you can become mentally addicted off the smallest effective dose of Ativan. Since it provides some relief, you might really like it, and decide (you/or the other) you want that to be a part of your life. Addiction probably won't happen instantly, but it will most likely be gradual. Also, having an addictive personality could go one or 2 ways. The addictive side begins to like the Ativan, and if you let that voice control you, you can easily end up becoming addicted and dependent. Or you're lucky, you don't care for the recreational value and just use it on an "as needed" basis.
I don't have much experience with Ativan since my main DOC for benzos was xanax, klonopin, and valiums. If I take 2mg of xanax everyday for 2 weeks, I'm defenitely going to feel a withdrawal, although it most likely won't be too bad. The longer you're on it, the harder your withdrawal will be. Since you're taking 1-2mg every other day, that's equivalent to 0.5-1mg of xanax. Taking that every other day can definitely give you a minor withdrawal probably starting 36-48 hours after your last dose. Should be very minor though. I've been through some really nasty benzo withdrawals and know if I go back to xanax, it's just going to get worse and worse every time I relapse and go on a little binge of taking them for 2 weeks at like 2-4mg. Caused me about a month-long withdrawal with the worst part of it faded after the 3rd week. I was shocked the WDs were so bad as I only took them for 2 weeks. I mean some days I was taking 6mg of xanax, but this WD was up there with my last withdrawal which was coming off of 8-12mg for a month. That was absolutely miserable. Didn't come out of the fog for months. It really took about a year for me to start thinking clear. Still think I'm going through PAWS, which I hear can take up to 2 years for that to go away. Sorry for this rant, but I haven't posted in a long time.