Hello there. Sorry to hear of your father's difficulties. Antidepressants takes time to act. Sometimes even up to 6-8 weeks. Your doctor will need to regularly see your father to assess improvement and increase dose of medications as per his response as well as his ability to tolerate medications. Please note that the presence of other medical illnesses like
thyroid problems,
diabetes,
vitamin deficiencies, etc can have a bearing in the response too. It would be good to ensure any such medical issues are also taken care of. Have faith in your doctor and discus your concerns. Wishing your father the best.