Hi there
Like Lizzie had previously said, this if often a side affect of medications such as an anti-depresent. I know I've gone through this before while I was on medication too. If you haven't long been on this medication, it might be that once it 'kicks' into your system and starts to work properly, the side affects will slowly stop. However, it might be helpful for you to bring this up in your next appointment with your psychiatrist. This way, for now they can at least keep an on your mood etc and then make any decisions about your medication in regards to whether for now you need to stick with it and see how it goes or whether you need to try another one
Jessie