Symptoms of Post Natal Depression (PND)
also known as Post Partum Depression

The severity of the illness depends on the number of symptoms, their intensity and the extent to which they impair normal functioning.

Mood Change - Low or fluctuating from high to low
Sleep Disturbance unrelated to baby's needs - sudden waking, bad dreams, early morning walking, inability to sleep even when the baby is asleep, over-sleeping
Appetite Disturbance - loss of appetite, forgetting to eat, over-eating
Chronic Exhaustion or Hyperactivity 
Crying or Wanting to cry 'without knowing why' 
Feeling unable to cope 
Irritability 
Sensitivity to noise 
Anxiety -hyperventilation, panic attacks, hot and cold flushes, heart palpitations, dizziness,
feeling as it 'you are not there'
Negative, Obsessive or Morbid thoughts 
Feeling life has no meaning 
Loss of Concentration 
Loss of Memory 
Loss of Sexual Interest 
Loss of Self Confidence and Self Esteem 
Unrealistic Feelings of Guilt, Inadequacy 
Fear of Being Alone 
Fear of Social Contact

Please see your doctor as soon as any of these symptoms appear, as management strategies can be discussed, and if not left too late. You wont end up in a psychiatric hospital like I did :-) They can be from other things such as thyroid problems or low iron levels, so it is important to get checked as soon as possible.