Here you go - taken from the 
Mental Health Foundation website
Signs of depression can include
    * Feelings of sadness that don't go away
    * Persistent low mood or emotional numbness
    * Losing interest and pleasure in your usual activities
    * Crying for no apparent reason
    * Feelings of irritability
    * Excessive anxiety, agitation or worry
    * Changes in your sleeping or eating patterns
    * Loss of energy, lethargy, extreme tiredness or fatigue
    * Lack of motivation
    * Reduced interest in sex
    * Feeling worthless or hopeless
    * Feeling guilty for no reason
    * Poor concentration and forgetfulness
    * Suicidal thoughts.
If you think you might be depressed, go and have a chat to your GP. They can help in so many different ways.