I am using Android Studio 0.5.8 currently so can't reproduce the issue as you said, But let me give you a way so that you don't need to restart Studio.
Prerequisite
You have to set your environmental variable to access adb commands anywhere through terminal
Reference link :https://sites.google.com/site/richgossweiler/home/android-development-notes/installing-the-android-sdk-on-windows
Try "adb devices" command somewhere to just make sure things are working fine.
Restart Android Studio if it is running .
you will see a Terminal tab inside Android Studio's bottom tab bar panel. open and run the following commands to restart the android debug bridge interface .
adb kill-server
adb start-server
let me know if it works for you.
enjoy the code with Android Studio.