Advice on antidepressants and ADHD medication. How do I get prescriptions for them here in Bangkok?

In Europe, I received regular monthly prescriptions which enabled me to get the necessary medication for my already diagnosed depression and ADHD issues. I moved to Thailand with several months worth of supplies. However eventually I will run out and that would be bad for me.

The medication I usually take for my depression is Zoloft, and I take Concerta for my ADHD.

I was thinking of finding a psychiatrist here in Thailand, then presenting them with my documentation from Europe which proves that I suffer from these conditions. Hopefully that would allow me to get the prescriptions I need so that I can buy the monthly medication I need.

Is this an option here in Bangkok? I don't want to have to go through a battery of tests again for a condition I've already been thoroughly diagnosed within Europe.

Also once I have already received the initial prescription here in Thailand, would I still have to visit the psychiatrist each and every month or can I make a phone call and pay a specific amount so that I can update my monthly prescription? This was how we do it in the country I live in Europe. You called once a month and they updated your prescription each month. I would rather avoid paying for costly consultations when all that's needed is my prescription to be updated.