It depends on what you mean by short term. I think for most medications to take effect, they need to be taken for several months before you wean off of them. They are not something you can take for just a few weeks or a month. I found it took several weeks of being on my medication to see improvement. I'm still learning about depression and medications, but from what I understand, it's different for everyone. Some people need to be on medication long term and others can take it for a while then wean off of it and be fine.
Are you also doing any therapy with your medication? That can be really helpful. I would recommend reading the book
The Feeling Good Handbook which talks about a therapy that can help you get out of your depression and keep it away. I started on my medication in January and along with therapy (and exercise) I have seen a dramatic improvement over the past 6 weeks.