Without medication, patients are wondering what comes next.

By the time Michael Kenneally found himself pacing outside a CVS drugstore in Cambridge, Mass., this summer, he was on a first-name basis with the pharmacist. Kenneally, 48, had been told multiple times that his Adderall prescription couldn't be filled. For 25 days, he continued to check by phone and in person.

Kenneally had been on the medication to treat attention deficit hyperactivity disorder, or ADHD, for 25 years. "It's been so long for me that I've been on it that it's difficult to function without it," he said.

That day at the pharmacy was the first time he felt like a drug addict, though, he said. "What am I doing here?" he remembered thinking as he looped back and forth in front of the glass doors.

Though he was finally able to fill his prescription after switching to mail delivery, Kenneally wonders every month whether there will be another delay. In October, the Food and Drug Administration confirmed what he and many other patients had already observed: There is a nationwide shortage of Adderall.

The agency's site maintains that the shortage is continuing, although some manufacturers have the medication available. A spokesman from the FDA said on Tuesday that the agency expected supply issues to resolve in the next 30 to 60 days. Teva Pharmaceuticals, one of the major Adderall producers, had trouble hiring workers over a year ago, which caused manufacturing delays. A spokeswoman for Teva told the Times that those delays have been resolved, but that the company is now facing "a surge in demand," which is the predominant cause for back orders.

Rates of Adderall use in the United States have been rising for 20 years. The use of prescription stimulants to treat ADHD doubled from 2006 to 2016. Adult women, in particular, have used the medication in growing numbers. During the pandemic, more people may have sought out ADHD medication to cope with the stress, Margaret Sibley, an associate professor of psychiatry and behavioral sciences at the University of Washington School of Medicine, told the Times in May. Online therapy start-ups have also advertised their ability to diagnose ADHD — and prescribe drugs quickly.

Kenneally, who is a process technician at a biopharmaceutical company, worries about how he will work without medication. Deep-seated fatigue set in within just a few days of being off Adderall, he said.

"The people that depend on the medication for daily functioning, for going to work, for being a good mother, for going to class, are struggling," said Fairlee C. Fabrett, director of training and staff development for the child and adolescent division at McLean Hospital in Massachusetts. "This is not something to make light of."

After an initial withdrawal period subsides, typically after a week or two, people still have to confront what comes next, as they face an unknown stretch of time without Adderall.

"It plays mind games with you," said Meri Romedy Barbian, a senior at the University of Mississippi who missed class to drive nearly two hours to the only pharmacy she could find with Adderall. "You're like, 'Oh my gosh, am I really this reliant on the medicine?'"

Adderall withdrawal: A 'zombified' state

Thomas Mandat, 24, who was diagnosed with ADHD in the third grade, hasn't been able to fill his prescription for a month. In his first two weeks without medication, he was so exhausted he couldn't eat; he forced himself to choke down protein shakes.

On his third day without medication, he sat down at his desk at a financial services company in Las Vegas and felt as if his head were filled with sludge. He described feeling as if he were in a "zombified" state: "It's like if you sleep eight hours, but it feels like you only got three," he said.

Not every patient who suddenly goes off Adderall will experience withdrawal, Dr. Fabrett said. But those who do may grapple with mood swings, irritability, appetite suppression and, in severe cases, suicidal thoughts. They might also experience headaches, jitteriness, intense fatigue and gastrointestinal distress, said Dr. Anish Dube, chair of the American Psychiatric Association's Council on Children, Adolescents and Their Families.

Brigid Groves, senior director of practice and professional affairs at the American Pharmacists Association, said the chance that patients would experience withdrawal symptoms increases the longer they have been taking Adderall and the higher their doses.

But even patients on a low dose of Adderall can experience withdrawal, Dr. Dube said. Short-acting Adderall may also be more likely to induce withdrawal symptoms than the extended-release version of the medication, which stays in the body longer, he added.

ADHD rebound symptoms

In addition to withdrawal, Dr. Dube said the ADHD that prompted patients to start medication in the first place can become even more severe when they stop medication abruptly.

Snezhana Kostornova, 31, a psychology student in Miami who was on Adderall until two months ago, has been struggling with rebound symptoms. A few weeks ago, she turned on her bathroom sink to hand-wash clothes but got distracted when she went to get soap; she watered her plant; then she started browsing for curtains online until water sloshed over her feet. Kostornova said she is just trying to get through the Adderall shortage day by day. She sometimes wears earplugs when she leaves home because the noises outside can be overstimulating, a symptom of ADHD.

Kostornova isn't sure how to plan for her future without a clear timeline for when the shortage will end. She wonders if she should postpone grad school. Should she tell her professors that she has hit a wall? Responding to texts from family and friends feels draining without her medication — should she explain that to them? "You just think, how much can you do without having your deck of cards fall down?" she said.

Without Adderall, Edward DiNola, 35, a game programmer and designer in Orlando, has become almost nocturnal; his sleep schedule is piecemeal and unpredictable. After a week without medication, he went to bed one day at 7 in the morning. "It's a bit of a curse to not have control over your own energy," he said. He was diagnosed with ADHD in his early 30s and found that Adderall "is like glasses for my brain," he said. "It brings me into focus and gives me a little more control."

Having taken Adderall for the last 12 years, Natalie Rotstein, 24, who uses they/them pronouns, said that being unable to access it is "a safety concern." They have been tightly rationing their doses over the last month, scared that one day they won't be able to refill their prescription. They're scared of blowing through a red light while driving through Los Angeles; at their neuroscience research job, they worry about forgetting to warn patients to take off jewelry before going into the MRI machine, which can cause skin burns.

Piecing together temporary solutions

For those who do go through withdrawal, there aren't many solutions for handling the depression and fatigue that can come with an Adderall crash, Dr. Groves said. In the meantime, it's important for patients to maintain basic health habits: staying hydrated, eating nutritious foods, getting enough sleep.

Dr. Dube said that patients who cannot access their medications should call their doctors right away and make game plans. Some doctors might recommend switching to another ADHD drug such as Ritalin or Vyvanse. Not everyone will respond to every medication in the same way, though, and often patients have tried other brands and settled on Adderall because it has fewer side effects.

"Once you find your medication and you feel good with it, it's very hard to change," Dr. Fabrett said. "It's not fair that we're putting our patients in the position to make these decisions." She advises patients to think about what they need to get through the shortage — and whether trying a new medication is worth the risk of side effects.

Patients are trying whatever they can to maintain a semblance of balance. Taryn Shumaker, a 34-year-old in Georgia, has been splitting her pills into halves or quarters — "I feel like I'm preparing my doomsday bunker," she said.

Kenneally switched to extended-release Adderall, which he finds less effective but was told would be easier to find. He also rations his pills, going without medication sometimes on the weekends so that he has enough to get through work.

Pausing on Adderall isn't an uncommon practice, Dr. Groves said — some patients take "medication holidays," even when there is not a shortage, but they should only do so in consultation with their prescribers, she said. And only certain ADHD medications can be split in half, she said, so it's important to also check with a doctor before doing so.

You can also speak with your doctor about spreading out doses, Dr. Fabrett said, or taking a lower dose. Patients can explore nonmedication options like cognitive behavioral therapy or seek a coach for people with ADHD

It's important to remember that these are stopgap solutions though, a path for people to get from Point A to Point B, Dr. Fabrett said. "This is not going to be forever."