Being a teenager is no fun. You are on a school trip to Venice with everybody having pizza for lunch and - was it the topping or something? - the world is turning very strange indeed.

It’s your 17th birthday and you find out that your relatives - none of whom has even sent a card before - are all coming to your party because they know that people in your family lose their sanity at 17.

You know you live in an insane, unjust world. Feeling a bit miserable, you go to an internet chatroom and the others persuade you to commit suicide.

You are a nice enough boy but you have this dream of kissing a shadow and you don’t know whether you want it to be a woman or a man.

All these somewhat unsettling scenarios are the bases for plays chosen by youth groups around Scotland for this week’s National Theatre Shell Connections regional festival (which ends tomorrow). However, Colin Bradie, whose Royal Lyceum Youth Theatre in Edinburgh chose Chatroom, is unfazed by the apparent doom and gloom of youth life.

“Although the themes are dark, the scripts are generally humorous and stylish. Anyway, at the Royal Lyceum, we like to let the young people read the plays and decide for themselves,” he says.

Shell Connections is one of the largest youth theatre festivals in the world and its format is bold and simple. Each year playwrights are commissioned to create hour-long plays for young people in the 11-19 age range: this year nine plays and a musical were written. Local groups apply to perform the play of their choice and then theatres across Britain and Ireland - 17 this year - stage a youth theatre festival of shortlisted productions. Each is seen by a Connections officer (Mr Bradie is one this year) and one production of each play is chosen to go to the National Theatre festival in July.

The Royal Lyceum is hosting Scotland’s festival and eight youth groups have been enjoying their hour in “the Big House”.

The poisoned-pizza eaters are the Shetland YT, the most northerly company, at the Connections festival for the fifth time.

“We might live on the islands but we are not insular in our vision,” says their director, John Haswell. “We like to feel part of the vibrant youth theatre movement.”

Haswell employed a professional acrobat to help train the cast for Lunch in Venice, by Nick Dear, teaching them skills that could be useful in later projects.

Gordonstoun School cast its advanced and scholarship drama students in its production of Samurai, a critique of consumerism by Geoff Case in the style of a Japanese parable.

The same play is the choice of the Tron Theatre’s Skills Workshop, a new Glasgow youth group appearing for the first time in the Connections festival and lucky enough to be going on to London in July. Lucky because merit alone does not earn the invitation: the organisers have to strike a balance between the plays, the regions and the age group of the players.

Balancing the choice of play is not simple. Chatroom, by Enda Walsh, is immensely popular all over Britain, and three Scottish youth theatres - Out of Eden (Inverness), Behind the Scenes (Buckhaven, Fife) and the Royal Lyceum - have chosen it. This is no bad thing, in Mr Bradie’s view. “Young people find it hugely exciting and stimulating to see how differently a script can be interpreted. It is maybe their first insight into the individuality and creativity of theatre.”

Like all the groups, the Royal Lyceum premi red its production earlier in the year, but Mr Bradie is breaking new ground in taking it on a short, local tour, playing in schools and offering workshops on the main themes of the play.

Youth theatre playing to young people, he feels, is a valuable segment of theatre mostly still to be explored.

The other youth theatres chosen for the Scottish regional festival are Borders YT, Ayr’s Borderline YT (playing 17 by Michael Gow) and, performing today, Glasgow’s Toonspeak YPT with Just by Ali Smith and Kildare YT, from Ireland, with Citizenship by Mark Ravenhill.

Connections, June 7-11, Royal Lyceum, Edinburgh, tel 0131 248 4848 www.lyceum.org.ukwww.shellconnections.org