Yes, provided it is correctly done. You can hang a picture of up to 10kg directly in the wall board using a fastener or a toggle bolt. Heavier objects (such as shelving, or a TV,) must be fixed through to the metal studs. These can be found using a magnet or by tapping, with the spacing normally being at 600mm centimetres. It is best to use a metal angle or bracket between two studs. Do not pre-drill the hole but instead use a type 17 drilling screw.