Children brought up within a religious sect may suffer mental problems if they leave to live in the outside community, a researcher says.
Jill Mytton, a former member of a religious group called the Exclusive Brethren, questioned more than 200 other former members, asking them general questions about how they had coped with the change.
And although most still felt loyalty rather than resentment towards the movement, they were suffering from a variety of other psychological symptoms.
Foremost of these was a feeling of alienation from society, and a lack of interpersonal skills.
Former sect members found it hard to form relationships with other people, said Ms Mytton.
And up to 30% of those who had returned questionnaires would benefit from some form of counselling or other help, she said.
The research was presented at a British Psychological Society meeting in Liverpool on Saturday.
The Brethren movement has many different sub-groups, but Ms Mytton focused on a branch called the "Taylorites" of the Exclusive Brethren.
There are thought to be approximately 27,000 in the Taylorite branch of the Exclusive Brethren worldwide.
Its members' beliefs involve strict rules which separate members from the influence of modern society.
Families do not have televisions, radios or computers. Children are often schooled within the brethren community wherever possible.
Members who leave the sect may find that, as their entire social network was within its community, they have to start again from scratch.
Ms Mytton found it was those who lost contact in this way who fared worse in her psychological assessment.
She said: "Leaving is quite a traumatic event - you leave your whole family behind, all your social circle - even your whole way of thinking.
"You have to go out and join a society which you have been taught is wicked."
She said that former members often displayed mild obsessive compulsive symptoms.
She believes that these problems will be reproduced in any sect which involves strict rules with a degree of isolation from society in general.
The Exclusive Brethren say that the separation from society and its influences represent a release rather than imprisonment for its members.
In a rare letter to the Evangelical Times in response to critical articles, three members said: "Far from being enslaved in legalism, brethren families are happy and free in the fellowship, practising separation as a welcome protection from television, videos, cinemas, and corrupt literature."