Four layers of curtains prevented Havva from ever seeing out of the window of the small apartment in an affluent neighbourhood of central Tehran that she once shared with her husband and young daughter. More importantly, as far as her husband was concerned, the thick folds of material ensured nobody could ever see in to catch sight of her — even though their apartment was on the second floor and overlooked only by a tall willow tree.

Not once in nine years of marriage was Havva allowed to pull those curtains back.

When I ask Havva gently what drove her to finally try to take her own life, she wrings her hands, revealing scars on her wrists. Over a period of four months she made numerous suicide attempts. The first were undoubtedly cries for help. The final time she thought she had ensured success by swallowing 140 tranquillisers and barricading herself in her home. But a last-minute call to a relative to say goodbye raised the alarm. Emergency services broke in, and she was rushed to hospital, where she remained on life support in a coma for several days. “There was no one incident that pushed me to do this, just very heavy pressure for a long time until I understood I couldn’t take it any longer,” says Havva, a strikingly beautiful 31-year-old who asks to be identified only by this pseudonym (meaning “Eve” in Farsi), since she comes from a rich and prominent Iranian family. “All my dreams were destroyed when I married at 17. There was no light, no hope in the way I was forced to live,” she says. She talks in a low voice of how she could never leave the house without her husband’s permission, nor make friends, work or resist him forcing himself on her several times a day. “But it is the traditional way. I thought that was all there was.”

Havva’s experience is far from unusual in modern-day Iran. Despite some advances in women’s rights over the past decade, and the fact that 60% of the country’s university graduates are now female, legally and socially women are still considered far inferior to men. In the words of the lawyer Shirin Ebadi, winner of the Nobel peace prize, “criminal laws adopted after the revolution took away a woman’s human identity and turned her into an incapable and mentally deranged second-class being”.

When Havva refers again to the curtains that she felt symbolised the crushing restrictions imposed on her by her marriage, the apartment feels claustrophobic and suffocating. It’s an all-too-common feeling in Iran today. As the country sits on the cusp of what many regard as the most significant presidential election since Ayatollah Ruhollah Khomeini deposed Reza Shah Pahlavi from his Peacock throne at the start of the Islamic revolution 30 years ago, denouncing westernisation and ordering every woman to cover herself with the chador, there is wide acknowledgment that Iran is sitting on a powder keg of barely suppressed fury at the stifling political, economic and social constraints its citizens have had to endure under the leadership of the current president, Mahmoud Ahmadinejad.

While deep discontent is felt at all levels of society, it is the women and young of Iran — 60% of Iran’s 70m population are under 30 — who are the most frustrated at the backward turn their country has taken in the past four years under Ahmadinejad’s fundamentalist administration. If this Friday’s presidential poll is truly open and democratic, which few believe it will be, their votes will be crucial in deciding the outcome, just as they were in propelling the reformist cleric Mohammad Khatami to power, twice, in landslide victories between 1997 and 2005. Khatami was prevented by a two-term limit from standing again in 2005, and it was then that Ahmadinejad, the ranting former mayor of Tehran and a religious zealot, took over the presidency. After throwing his clerical hat into the ring once more in the early stages of the current race, Khatami quickly withdrew, having reportedly been warned by the country’s ultra-conservative forces that he would suffer the same fate as Benazir Bhutto if he continued, leaving the opposition reformist camp fielding little-known candidates.

It was when Khatami was still in power that I last visited Iran, nearly 10 years ago. The light he let into this long-suppressed society by throwing open the country’s political curtains, if only partially, was refreshing. Though, even then, the conservative mullahs who opposed him, and who pull the real levers of power in Iran by controlling religious institutions that run parallel to and oversee every branch of government, saw to it that most of his reformist legislation was quashed. Hundreds of activists continued to be jailed and killed. But during his time in office, Khatami oversaw a brief flowering of civil society, advocated freedom of expression and promoted a series of legal reforms to the rights of women. These included giving women limited divorce rights, previously reserved only for men, and easing constraints on the Islamic dress code that had once made shedding the chador an offence punishable with prison and 74 lashes.

At that time there was an explosion of colour on the streets of the capital, with growing numbers of women throwing off the drab floor-length black cape in favour of knee-length coats and shoulder-length head coverings or bright headscarves. In the past four years, many women have gone back to wearing the chador, not out of piety, but out of self-protection as the country’s “morality police” are once more omnipresent, stopping, fining and arresting girls and women whose hijab is not “modest” enough, resulting in a police record potentially preventing them from getting a job or studying in future.

But during the easing of social constraints overseen by Khatami, Havva was finally able to divorce her husband. She has since acquired a psychology degree and supports herself and her 11-year-old daughter by working with an organisation that counsels young people on how to avoid depression. In recent years, the demand for such help has burgeoned beyond the capacity of Iran’s mental-healthcare professionals. Iran’s suicide rate, especially among women, is increasing, as is prostitution, alcoholism and gambling — though there are no reliable statistics on the prevalence of any of these as, officially, such problems do not exist.

The one serious social problem the government is unable to deny is drug abuse; Iran now has the highest rate of opiate addiction in the world. Ten years ago it was officially confirmed that there were 2m heroin and opium addicts in Iran, then equal to 2.8% of the adult population. This figure is thought by some to have now doubled.

“In a society where so much is prohibited, everything somehow becomes allowed,” says an Iranian expert on drug abuse. “As soon as a young person buys a forbidden pop CD or DVD of a western movie or banned alcohol on the black market, he or she comes into contact with an illegal underworld, and that is quickly exploited. I worry the moral decay in my country is increasing so rapidly that a point will be reached soon where it is very hard for us to turn back,” she adds. She, too, requests anonymity for fear of government reprisal for airing such pessimism.

In stark contrast to the cautious, but outspoken, optimism of some of those I met a decade ago, an atmosphere of extreme suspicion and paranoia now prevails in Iran. As I struggle on occasion to understand what people are trying to tell me, my interpreter explains that his countrymen have become used to talking in metaphors rather than saying clearly what they feel. “In Iran there is an expression that the walls have mice and the mice have ears,” says one young woman, meaning that Iran’s intelligence service is 70m strong — the country’s entire population.

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