There is a strong possibility that you're depressed, but you don't know it. You might feel tired, or just out of sorts more often than you use to. To find out if you might be suffering from depression, here are some signs and symptoms:
Insomnia and always tired
Changes in eating habits — more or less eating and drinking
Feeling ill frequently, many colds and coughs, generally 'low' physically
Lack of interest in things — hard to be motivated or unable to find pleasure in the world around you, feelings of hopelessness
Low mood over a period of time — longer than two weeks
Unable to make decisions, struggling to make your mind up over little things as well as big decisions
Loss of interest in or unable to participate in sex
Forgetful or a poor memory
Feeling emotional or 'wobbly,' for much of the time.
You want to withdraw and be on your own. Excessive sleeping or sleeping less than six hours.