Beautiful minds: Outsider art at the Wellcome Collection

The first major exhibition of Japanese Outsider art in the UK brings together 46 artists who live on the margins of society. It's remarkable, says Adrian Hamilton

Art has been employed as therapy for the mentally ill ever since psychiatry began. But if you think of it as a tool to exorcise the demons through self- expression that is not how the Japanese view it. For them it is a matter of occupational therapy, a means of work and concentration to soothe the troubled mind. You don't use art to work through issues but to ease them

You can see the difference in an exhibition of what the Western art world has come to term Outsider art in a remarkable exhibition at the Wellcome Collection. Where a similar show drawn from Western institutions might be expected to display works of contortion, anger and pain, the Wellcome display is quite the opposite. By the end of viewing the works from 46 artists living in or attending social welfare establishments across Japan, you feel quite cheerful. The overwhelming impression is not of the angst of the disturbed or constricted mind but the sheer pleasure that the act of creation has given the patients.

Although the exhibition has been given the somewhat pretentious title of Souzou, a Japanese word meaning both creation and imagination depending how it is written, the gallery quite rightly lets the pieces speak for themselves, without much explanation or reference to the mental problems of the patients. Instead, the curator, Shamita Sharmacharja, who has toured Japan's welfare institutions to pick the works, has grouped them by artist under a series of themes.

First off is that very Asian pursuit of building pictorial characters in which words are written into a form of pattern-making in itself. Using their own names or particular word associations, artists such as Mineo Ito and Toshiko Yamanishi pursue the forms obsessively into shapes and rhythms across the page. Concentration is the feature of most of these works. Whether it is with clay, textiles or pen and paper, there is the sense of the creative mind starting from a basic point, usually the material itself, and working it through to a conclusion.

Satoshi Morita's tapestries are made up from discarded thread ends, Shota Katsube makes figures out of the wire ties you use to do up bin liners, and Seiji Murata employs the offcuts of the paper from his place of work. Particularly effective are the pastels of Takashi Shuji, who commences with a dense block of monochrome and then thins and spreads it into the shapes of the everyday objects he sees around him. On the basis of this show at any rate it would seem that Japan's welfare facilities are a lot better supplied with craft equipment than the average institution here.

As the show opens up, so does the work. The abstract graphics in ink and crayon become bigger, the figurative art bolder. There's a marvellous sequence of pictures by Takako Shibata of her absent mother, in which the figure takes up ever more of the space and the eyes become more dramatic, while Nobuji Higa's nudes are both erotic and threatening. It is in the use of pen and ink, precisely graded and varied, that the works are most intense, but it is in ceramics that they become the most imaginative. There are some really splendidly childlike figures as well as cheerfully grotesque.

Theoretically, art such as this should – or so we like to pretend – come from inside without the intermediation of outside artistic influences. But this is Japan and it is not long before we are in the realm of manga comics, newspaper advertising and pop imagery, copied with splendid brio and often with a good deal of irony. The most compelling piece in the show comes towards the end. Titled by the artist: 3 Parks with a panoramic view. A 360 degree world of panoramic view – Ferris Wheel, clusters of building with magnetically-levitated trains, past present future, a suburban town with railroad bridges, a city under development with indigenous peoples and natural resources-.

A 10-metre long work in progress by the youngest artist in the exhibition, Norimitsu Kokubo (born 1995), it starts as a conventional map of a city marked with roads and blocks of building but then gradually becomes more descriptive and more fantastical as the teenager works along the unfolding sheet of paper, drawing the skyscrapers, inserting Ferris wheels and lakes and trains and buses. You can see the mind at work but also the delight as it develops. It's the same spirit that informs the animated films of Studio Ghibli.

Should we regard it as art? Europe with its modernist fascination with primitive art, would certainly have it so. Jean Dubuffet founded a whole movement after the Second World War called Art Brut, trumpeting the virtues of an art uncontaminated by training or culture. In recent years, there has been an increasing tendency in “encyclopedic”and Outsider shows to proclaim the expressions of the untrained as somehow more authentic and more meaningful than the Conceptual, Abstract and post-modern works of the trained.

The origin of this Wellcome exhibition lay, in fact, in two much smaller shows in the Netherlands and Paris and several of the artists have been taken up by commercial galleries in Europe. The ceramicist Shinichi Sawada, still only 30, has been picked for Massimiliano Gioni's Il Palazzo Enciclopedico at this year's Venice Biennale, while both the artist known as M.K., who takes the imagery of advertising and subverts it with words, and the self-reflective Marie Suzuki, who uses pen on paper, have been taken up by commercial galleries.

It rather defeats the point, however, if these works are taken out of the realm of their therapy and into the realm of commerce. The works of these artists retain their freshness precisely because they aren't self-consciously arty. But then nor are they primitive. The last thing any of these artists would want is to be regarded as deliberately naive. Indeed, it is their attachment to the formal qualities of craft that mark them out. But they are what they are without making them into something else.

Their wonder is not just the product but what it tells you of the creative marvel that is the human mind, even under stress. It gladdens the heart.

Souzou: Outsider Art from Japan, Wellcome Collection, London NW1 (020 7611 2222) to 30 June