Reciting the same prayer repeatedly in case they lack devotion, worrying endlessly whether they are clean enough for synagogue and fretting endlessly about their conduct to others — these are some of the problems seen by therapists who treat observant Jews suffering from obsessive compulsive disorder.

One woman confessed to an online forum that she takes four hours to prepare for her monthly immersion in the mikvah or ritual bath and, even upon return home, “can’t stop worrying” that she might have missed an aspect of her preparation.

Does following a religious system full of obligations, practices and rituals push people towards OCD?

“There is a whole body of research and the general consensus is no,” says Steven Friedman, an American psychiatrist with expertise in OCD and observant Jewry. Head of the phobia and anxieties disorders clinic at SUNY Downstate Medical Centre in New York, Friedman says: “It’s just that OCD tends to attack what is most important to people.”

So, while for many people OCD can translate into hygiene concerns, for observant Jews it is likely to manifest itself in religious matters — could the milky drink actually be in a meaty cup? Has a particular ritual been performed correctly?

Among male patients, Friedman says obsessions often relate to prayer and cleanliness for prayer — including post-toilet wiping, which can be extreme.

Among women, there can be sharp fear about whether somebody’s feelings have been hurt or about family purity laws.

Jewish-observant OCD sufferers frequently ask their rabbis endless questions regarding practice and it has been suggested to Friedman that 99 per cent of rabbis’ questions are asked by one per cent of their congregants. He says this statistic is an exaggeration but acknowledges it may point to a truth.

Recommended treatment for OCD among observant Jews is the same as for other populations — therapy (see opposite).

Religious figures are increasingly careful to draw a line between piety and obsession and often find sensitive words with which to reassure members of the community.

The online forum messaged by the woman who spends four hours preparing for the mikvah — a site run by the Jerusalem seminary Nishmat — had a clear response for her.

“We would like to emphasise that the laws of niddah [family purity], like the Torah itself, are designed for human beings in all their imperfection and not for angels,” wrote Nishmat’s staff, emphasising that unintentional transgressions are not as serious as wilful ones and wishing her “strength to be more trusting and forgiving of yourself”.

One of the best-known books on the subject is written by Avigdor Bonchek, a clinical psychologist and rabbi. He says OCD can cause people to distort the performance of mitzvot and the problem can tarnish their religious practice with pain and suffering.

“Under the guise of religious observance, countless Jews are held prey to obsessive compulsive disorder,” say the publishers of Religious Compulsions and Fears: A Guide to Treatment.

“And this book has what it takes to break out of the horrible cycle of entrapment.”

Bonchek turns to the Book of Proverbs to make the point that the obligations of the Torah are not meant to be psychological shackles but rather — citing a phrase sung in synagogue as the Torah is put in the ark — “ways of pleasantness”.