I am really uncomfortable with this appearing in my EMR.
Be concerned, but don't be obsessed.
It does happen sometimes, and some of the peeking happens at HR, billing, employee health. I doubt all EMR systems log who sees your record at these non-provider departments. I think most people in your health system and most co-workers would find gossip about this to be disgusting and would be unlikely to continue it. However, if the gossip got more juicy (like if Seroquel was added as an adjunct), then chances of disclosure and gossip spreading would go up. So it might be more worth pursuing care outside the system if something changed.
Personally, I'm pretty private.
My house and car are not in my own name.
Once out of residency, I always opted to get all medical care outside my own system. If the only insurance offered by my employer was within the healthcare system where I work, I would be getting any care related to mental health outside that system - on a cash basis. But I would not withhold that info from applications for Long-term Care (LTC), Life Insurance, Long-term Disability (LTD).
BTW, VERY smart of you to be thinking about this. LTC and LTD health issues often bankrupt families, even doctors. Imagine your family living on the $ you would get from SSDI after you get a TBI. LTC, LTD rates are, of course, lowest when you are young and healthy.
Also, you are right that certain insurances can be significantly adversely affected by some health problems and medications, insurance like Life and Long-Term Care (nursing home, home health, hospice) and Long-Term Disability can all be negatively affected by certain conditions. However, if you hide the info from insurers and they figure it out - you may be blacklisted among insurance companies forever. If one insurance company rejects you, they can (and do) share that info with other companies - not your medical info, but that you were rejected, and probably that you were rejected for lying on your application. Also, if you lie to the insurance company and they don't catch it, but then 40 years later you submit a claim, they may review your application very thoroughly and could reject you at that time (40 years and a fortune of premiums later) for having lied on your application. That's right. Now that have MS, you are uninsured and cannot get insurance. You can't even get Medicaid until you sell your house and empty your bank accounts paying for medical care.
On the issue of long-term insurance, talk to someone who knows. Go talk to a reputable broker of LTC/LTD insurance and life insurance and discuss the issue - without filing an application. Ask how often in his/her experience this condition and these medications cause a rejection. Ask if the reason for the prescription changes anything about acceptance/rejection rates. For instance, does getting a Rx for and AD for depression look different to underwriters than getting it for anxiety, or for smoking cessation, or for attention problems. Then, of course, go talk to another broker for a second opinion.