One recent morning, three figures in white lab coats descended cautiously into a pitch-black netherworld beneath a crumbling bridge in the Afghan capital. They picked their way amid garbage and sprawled limbs, passing hundreds of huddled men whose gaunt, wary faces were briefly illuminated by the flare of matches and drug pipes.

The doctors were headed to a lone tent pitched nearby on the dry riverbed, where they knew a female addict named Marzia had been sleeping on her own. They approached quietly, saying they had come to help. From within came shouts of, "Go away, leave me alone!" Suddenly the young woman flung open the tent flap, cursing and hurling debris. Stumbling along the riverbed, she darted under the bridge and vanished into the protective company of fellow lost souls.

Drug addiction in Afghanistan, once mostly limited to men who spent years as laborers or war refugees in Iran, has exploded into a nationwide scourge that affects millions of people, including a growing number of women and children.

A drug-addicted woman who was admitted the day before sleeps on the floor where she fell in the detoxification ward last month at the National Center for the Treatment of Addiction for Women and Children in Kabul. The center, which opened several months ago, is one of the few such facilities for women in Afghanistan. (Andrew Quilty/For The Washington Post)

Over the past five years, programs of crop eradication and substitution have been largely abandoned as foreign funding has ended and insurgent attacks have increased. As a result, tens of thousands of farmers have returned to the lucrative business of growing opium poppies. Last year, 420,000 acres were devoted to poppies, and opium production rose 43 percent over 2015, to 4,800 tons, according to the U.N. Office on Drugs and Crime.

Most Afghan opium is sold for export to the heroin trade in Europe and Russia, with an estimated revenue value of nearly $1 billion. But the boom has also led to a sharp drop in domestic drug prices, while widespread unemployment and anxiety created by years of war have fueled demand for the cheap escape of drugs.

In 2010, U.N. experts estimated there were about 1 million regular drug users in Afghanistan, mostly using opium as "a kind of self-medication against the hardships of life." They warned that addiction was "following the same hyperbolic growth of opium production." By 2015, they reported, the number of addicts in the country had soared to 3 million - an astonishing 12 percent of the populace - and more of them were using heroin.

Today the problem has burst into the open, overwhelming police and public health agencies. Dirt-streaked men can be seen passed out on almost any sidewalk in Kabul, and the few treatment centers are constantly full.

Children of drug-addicted women with a nurse after a class at the rehab center. They are separated from their mothers for study and play. (Andrew Quilty/For The Washington Post)

The most startling aspect of the drug boom, though, is still largely hidden from sight. Tens of thousands of Afghan women, confined to their homes by tradition and often dependent on addicted men, are succumbing, too. This has created a growing phenomenon of drug-centered households where family relations, economic stability and social traditions can easily collapse.

"It is a silent tsunami, and if it is not controlled, in another few years it will be a disaster," said Shaista Hakim, a physician and drug rehabilitation specialist who works at the recently opened National Center for the Treatment of Addiction for Women and Children in Kabul.

During the Taliban era, when drugs were banned, "you could hardly find a woman using hashish, and even more rarely opium," Hakim said. But in the past five years, she said, the number of female addicts has tripled. "Every woman here has problems like mountains, layer on top of layer," she said. "They are so vulnerable, and their addiction involves the entire family, so we have to treat the entire family."

According to experts, most Afghan female addicts are introduced to drugs by their husbands or other male relatives. Daily routines collapse, and traditional Muslim norms - including women's expected role as modest, devoted wives and mothers - are upended by the frenzy of hunting for drugs and the haze of getting high.

  A woman recently admitted to the National Center for the Treatment of Addiction for Women and Children in Kabul is calmed by nurses and doctors after collapsing in a corridor during withdrawal from her opium addiction. She was brought to the facility by her 16-year-old daughter, who insisted she stay there until she recovered, saying,

Some women become prostitutes or thieves. Children are given opium to keep them quiet, sent out to beg, turned over to orphanages or sold into marriage to pay for drugs. At their most desperate, younger women gravitate to drug markets such as the infamous addicts' colony under the Pule Sukhta, or burned bridge, in southwest Kabul, where they can share a pipe, purchase a baggie of heroin for pennies and hide from the world.

"The addicted women feel safe there among the men, even though it's dangerous and some abuse them," said Hakim, who regularly visits the bridge area with her co-workers. "If they come with us, we can help them recover, but then they have to face the shame and gossip of being identified as an addict. For a woman in our society, that is worse."

The new rehabilitation center, run by the Ministry of Public Health but funded largely by the U.S. government, houses and treats women for 45-day stints of detoxification and therapy at no cost. The premises are locked and guarded; no women are allowed out, and no men are allowed in except for limited visits. Children are welcome to stay, but they are separated from their mothers for play and study, and some are also under treatment for addiction.

At the moment, 72 women and children are living at the center, a brightly decorated, four-story hive of activity. Some of the women were found by the medical intervention team at Pule Sukhta or picked up there by police and transferred to the center in lieu of arrest. Others have checked in voluntarily or been brought by relatives from other provinces. Almost all are uneducated; the center offers literacy classes as well as training in tailoring and hairdressing.

During a recent visit by a Washington Post reporter and photographer, the staff tried to keep things orderly, but emotions ran high and drama erupted often. Several women going through withdrawal pleaded to go home, swearing they would never touch drugs again. There were sounds of pounding on locked doors and babies wailing.

The only quiet area was a dorm room where two disheveled women who had just arrived from Pule Sukhta were sprawled in sleep.

Some patients were reluctant to tell their stories for fear of family gossip or public stigma. Others were proud of their progress and eager to explain the paths that had led them to drugs, as well as the hard choices they had made to escape them.

Their tangled tales had some common threads: addicted and jobless husbands, children taken away and sent to orphanages, conflicts with disapproving relatives, and lives of poverty and wartime hardship in which drugs offered short-term release but caused lingering damage.

"I want the world to know what I went through," said Shaimsa Khan, 26, who was about to complete her second 45-day stay. She said she had run away from her addicted husband and tried to kick drugs at the center. But after health authorities refused to return her young son, she relapsed and found herself drawn back to the addicts' colony.

"I was alone and had no one to protect me. It was better under the bridge than going off with a strange man," Khan said.

At lunchtime, the women and children crowded together on the floor, eating bowls of stew and bread. Suddenly there was a commotion at the front door. A gaunt woman had arrived, weeping and shrieking in protest. Her three children were with her: a slender, grim-faced girl of 16 and a distraught 9-year-old boy who took turns holding a year-old baby.

As the argument continued, it became clear that the mother had not brought her children; they had brought her. The daughter, Mahdia, who has never been to school, alternately scolded and soothed her mother while explaining the situation to the center staff. She said her mother's addiction was out of control, that she kept running away to find drugs, and that she had forced both Mahdia and her sister to marry older men so she could use the dowry money to buy drugs.

"She is our mother, but she has ruined our family," Mahdia said, balancing the baby on her hip. "She goes to the bridge, and if she doesn't find drugs she beats us, and she faints all the time. I want her to be healthy, not crazy. I want us to have a normal life."

The girl handed the baby to her brother and put her arms protectively around her weeping mother's shoulders, but her eyes were hard with resolve.

"It doesn't matter what she says. She must be kept her here until she recovers," Mahdia said. "There is no other way."