Hundreds of thousands of children, some as young as 5 years old, are used as child soldiers around the world. Children are vulnerable to manipulation and drawn into violence due to their emotional and physical immaturity. Girls make up a third or more of child soldiers in some countries, where they face risks of rape or being forced into marriages with commanders. Surviving child soldiers often suffer trauma, injury, abuse and psychological scarring that can lead to conditions like PTSD. Their brain development is also physically altered in areas related to emotion and memory.