The term 'angst-ridden and moody' can be summed up by the word 'EMO', which is a three letter acronym. EMO is an abbreviation for 'EMOTIONAL, ' and it is used to describe someone who is often overwhelmed with feelings of anxiety, depression, and sadness. This person may also be prone to mood swings and have difficulty controlling their emotions. They may also be seen as being overly sensitive or dramatic. In short, someone who is angst-ridden and moody can be described as an EMO.