"I know people don't regard it as normal, but I don't care," says Vickie, 42, from Basingstoke, Hampshire.
ADHD's main symptoms are hyperactivity and impulsive behaviour, thought to be caused by underactivity of chemical neurotransmitters in the brain. Diagnoses have soared in recent years - the NHS estimates that between two and five per cent of school-age children suffer to some extent, although some experts believe the rise is due to other health complaints or a child's natural exuberance being misdiagnosed.
While there is no cure, the most common treatment is methylphenidate, a stimulant commonly known by the brand name Ritalin, which increases the activity of the neurotransmitters dopamine and noradrenaline. Figures last month showed that prescriptions for Ritalin have more than doubled in a decade, reaching almost one million last year.
Jessy, diagnosed with ADHD in February, has been taking Equasym XL, another brand of methylphenidate, since March, but Vickie maintains breastfeeding is essential in helping to calm him. There is no research to support her claim, although breast milk does contain naturally occurring chemicals that induce sleepiness.
Research also shows that nursing may protect against ADHD developing in the first place. In June 2013, a study by Tel Aviv University found that children who were bottle-fed at three months of age were three times more likely to have ADHD than those breastfed during the same period, but it is not known whether this was due to the breast milk or the bond formed between mother and baby.
Being breastfed since birth, however, did not prevent difficulties with Jessy. "As a baby he wouldn't sit still for longer than 15 minutes. If I put him in a car or buggy, he would scream," says Vickie, who quit her job as a financial crime auditor when Jessy was six months old and now works from home as a jeweller. "As he got older, he was so destructive we would be reduced to tears."
The only thing that calmed him was being close to his mother, and for the first six months Vickie breastfed him up to 18 times a day.
Last September, she enrolled him at nursery, where his behaviour led the manager to assign a member of staff to supervise him. This prompted Vickie to visit her GP. In February, Jessy was referred to a child psychologist who, with a psychiatrist, diagnosed him with severe ADHD. "The diagnosis was devastating, but at least we knew Jessy wasn't just being naughty," says Vickie.
The psychiatrist told Vickie she should stop breastfeeding. "But he couldn't tell me why, so I won't."
Some experts say she is right to stand her ground. Breastfeeding specialist Catherine Cooper, based in London, says: "Breastfeeding is a natural and progressive relationship between a mother and child and, if left to the child, weaning happens between two and a half to seven years of age. In other societies, this is seen as perfectly normal."
But Andrea Bilbow, chief executive of the National Attention Deficit Disorder Information and Support Service, is sceptical breastfeeding has any particular benefits to children with ADHD. "Breastfeeding will keep a child calm, but so will hugging them or giving them a dummy," she says.
Alison Roy, a child and adolescent psychotherapist with mental health services in Sussex, says: "It could be Jessy has worked out a reassuring, regular form of contact with his mother that has helped him to self-regulate his emotions. But children with ADHD still need to separate from their mothers, physically and psychologically, for the healthy development of their personality."
Vickie's partner, Joao Da Mata, 45, a television presenter on a horse-racing channel, is sanguine about his son's continued breastfeeding. "It has been the best thing for Jessy," he says.
Since being on medication Jessy has learnt to play with his cars for half an hour and to sit on the sofa for 20 minutes at a time. But Vickie says she will continue to breastfeed as long as it helps him.
"Jessy won't be breastfeeding when he's 18, but I have no intention of stopping until he's ready," she says. "All we want is to be able to lead a normal, happy family life, and if breastfeeding helps us to do that, I don't see why he should stop."