Thank you for asking the question.
Anti-depressants are controlled under "schedule 3 poisons act", meaning, there is no restriction for any licensed doctor to prescribe these medicines.
There are however GPs who are more comfortable prescribing certain drugs compared to others. There are also some GPs who are better trained at recognising and treating mental health conditions.
There is unfortunately no way for the public to know at the moment, because only the government has a full listing of these clinics. I can tell you off hand that I am one of them. We are partnered with the government to provide subsidised psychiatric medications. Another one is Dr Alvin Lum and Dr Laurel Yip.
Certainly anti-depressants can cause loss in sexual interest in some patients. Keep in mind however then the condition that requires these medications also cause a loss in sexual interest. Your doctor would have considered the pros and cons properly before giving you the medication. If you have any issues with the medications, you should discuss with your doctor soon.
Take care.