A generation of very young girls is being psychologically damaged by inappropriate "sexy" clothing, toys and images in the media that are corrupting childhood, leading psychologists warn today.

They say marketing takes unfair advantage of children's desire for affection and the need to conform, leading to eating disorders, low self-esteem and depression.

Their report echoes a warning by the Archbishop of Canterbury, Dr Rowan Williams, and follows a United Nations study last week saying that British children were the unhappiest and unhealthiest in the developed world.

The American Psychological Association's report says inappropriate marketing is leading to the sexualisation of children by a consumer society.

Apart from clothing for five- and six-year-olds, with old-fashioned frilly frocks replaced by mini skirts, plunging necklines and sequined crop tops, the report specifically criticises "Bratz dolls".

These outsell Barbie dolls in Britain by two to one and come dressed in miniskirts, fishnet stockings and feather boas.

Disney's Little Mermaid or Pocahontas "which have more cleavage, fewer clothes and are depicted as sexier than characters of yesteryear" are also picked out.

"The consequences of the sexualisation of girls in media today are very real and are likely to be a negative influence on girls' healthy development," said Eileen Zurbriggen, the APA's task force chairman. "As a society, we need to replace all these sexualised images with ones showing girls in positive settings. The goal should be to deliver messages to all adolescents — boys and girls — that lead to healthy sexual development."

Her comments were endorsed by Dr Jean Kilbourne, the co-author of a forthcoming book So Sexy, So Soon: The Sexualisation Of Childhood, who said clothing, toys and adverts were shaping a child's gender identity and values in the wrong way.

She saw a direct link between what was happening and the rise in under-age sex.

Dr Kilbourne told The Daily Telegraph: "You see these clothes everywhere, tight T-shirts for little girls saying 'so many boys, so little time', that sort of thing.

"Parents think it is clever but they cease to think that when their child becomes sexually active at 12. There is huge pressure on girls to look sexy and dress provocatively at a younger and younger age and boys are getting graphic sexualised messages. But parents can say 'no' and refuse to buy this stuff."

Recently Asda was condemned for marketing black lacy underwear to nine-year-old girls.

Last night Sue Palmer, the education consultant and author of Toxic Childhood, said: "The same mothers that dress their daughters up like tarts are probably the mothers going on demos against paedophiles. They don't make the connection between how they are dressing children and what they are so frightened of — paedophilia." A Bratz spokesman said its dolls were bought by over-eights. "The Bratz brand, which has remained number one in the UK market for 23 consecutive months focuses core values on friendship, hair play and a 'passion for fashion'."

The spokesman quoted Dr Bryan Young, a psychologist at Exeter University, as saying "parents may feel awkward but I don't think children see the dolls as sexy. They just think they're pretty".