When he reached the age of three, this pattern reversed and he began sleeping excessively in the afternoons.
As he grew older, Helen and Paul began to notice other oddities in Tom's behaviour.
Her theory is that giving children antibiotics in the first year of their lives - or during pregnancy - damages the lining of the bowel, making it more porous.
This damage affects the way people with autism digest their food.
The devastating symptoms affected almost every area of his life.
At nursery as other children played he would sit alone, engrossed in his own thoughts and obsessively lining up his toys. Despite being told by doctors that her son's condition was incurable, Helen has found a treatment has improved Tom's condition beyond recognition.
These peptides are then broken down into smaller particles that can easily pass through the wall of the intestines.
Long car journeys with young children - full of endless questions, chatter and games of I Spy - leave many parents with a headache.
But until recently mum Helen Bennett positively longed for her little boy to behave just like that.
But he was immediately put on antibiotics to protect him from a virus he had picked up in the womb and as he grew his ill health continued.
'As a baby, he was always vomiting and seemed to pick up every virus that was going,' says Helen, 38. For the first two years of his life, he would only sleep for two or three minutes at a time before waking.