In the United Kingdom, for instance, a government-supported trial involving 475 people with early-stage dementia found that after cognitive rehab, most participants attained their goals, while those in a control group did not, and they maintained improvement at three months and at nine months.

“We can’t wait another 20 years for some magic pill,”

This approach may represent the future for the growing number of older adults around the world with dementia. Trials of drugs to prevent or treat dementia have failed over and over. Even if some future treatment demonstrated effectiveness, millions of people and their stressed family caregivers need help now.

Cognitive rehab has its limitations. “We never suggest this can reverse the effects of dementia,” Dr. Clare said. It will not raise participants’ scores on tests of mental ability.

The practice brings occupational and other therapists into the homes of dementia patients to learn which everyday activities they’re struggling with and which abilities they want to preserve or improve upon. Organizing a visit with a friend, perhaps. Keeping track of the day’s appointments and plans. Heating a prepared lunch without burning it.In weekly sessions over several months, the therapists devise individual strategies that can help, at least in the early and moderate stages of the disease. The therapists show patients how to compensate for memory problems and to practice new techniques.

Dr. Clare directed a recent trial of cognitive rehabilitation in England and Wales in which the patient was enrolled. Cognitive rehabilitation, which Dr. Clare has been researching for 20 years, evolved from methods used to help people with brain injuries.

The program’s services closely track people’s conditions using two standard questionnaires filled out each week of treatment — one for depression and one for anxiety — and log the findings in a government database (clients are anonymous in those reports).

She did, in time, improve, and is very grateful for the treatment. The same cannot be said with any certainty about the 40 percent of people who the data show were lost to the program after the initial assessment phone call. About two-thirds of them were not depressed or anxious enough to qualify for the therapy, or decided it wasn’t for them

For those outside England trying to improve access to mental health care, these problems pale in the face of untreated emotional problems, which are most common in young people.

Oliver’s condition was judged serious enough that he got in to see a therapist face to face fairly quickly, within a few weeks. He learned he had obsessive-compulsive disorder. People with O.C.D. have a consuming fear — of germs, say, or, in Oliver’s case, of misbehavior. They escalate that fear by repetitively trying to soothe it, for example by washing their hands or checking that they’ve done nothing wrong.

This so-called stepped care approach is similar to the triage most clinics traditionally do, only it is more rigorously standardized and monitored, saving the high-intensity, face-to-face treatments for more severe problems — a system intended to contain costs.

This first call is more than a scheduling exercise. It is an initiation of therapy, a partly scripted, hourlong evaluation to determine how safe the new client is, how desperate and why. The staff members, known as psychological well-being practitioners, decide in that initial call if low-intensity phone therapy is appropriate, or if the person should be moved up the ladder, to group or individual therapy.

Oliver might have gotten a drug and, possibly, some general psychological guidance and support. But he had never sought mental health treatment before, and he most likely would have gone years before getting any talk therapy because he had no idea it was available. The area where he lives had scores of practicing therapists but no centralized system for ensuring that people got scientifically backed approaches tailored to their specific problem.

It set up 35 clinics covering about a fifth of England and trained 1,000 working therapists, social workers, graduates in psychology and others. The program has continued to expand through three governments, both ideologically left and right leaning, with a current budget of about $500 million that is expected to double over the coming few years.

The enormous amount of data collected through the program has shown the importance of a quick response after a person’s initial call and of a triage-like screening system in deciding a course of treatment. It will potentially help researchers and policy makers around the world to determine which reforms can work — and which most likely will not.

Mental health professionals also say the program has gone a long way to shrink the stigma of psychotherapy in a nation culturally steeped in stoicism.

The demand in the first several years has been so strong it has strained the program’s resources. According to the latest figures, the program now screens nearly a million people a year, and the number of adults with common mental disorders who have recently received some mental health treatment has jumped to one in three from one in four and is expected to continue to grow.

Mental health care systems vary widely across the Western world, but none have gone nearly so far to provide open-ended access to talk therapies backed by hard evidence.

The rapidly growing initiative, which has gotten little publicity outside the country, offers virtually open-ended talk therapy free of charge at clinics throughout the country: in remote farming villages, industrial suburbs, isolated immigrant communities and high-end enclaves. The goal is to eventually create a system of primary care for mental health not just for England but for all of Britain.

England is in the midst of a unique national experiment, the world’s most ambitious effort to treat depression, anxiety and other common mental illnesses.

Numerous species have conspicuous, metabolically costly and physically burdensome sexual ornaments, as biologists call them. Think of the bright elastic throats of anole lizards, the Fabergé abdomens of peacock spiders and the curling, iridescent, ludicrously long feathers of birds-of-paradise. To reconcile such splendor with a utilitarian view of evolution, biologists have favored the idea that beauty in the animal kingdom is not mere decoration — it’s a code.

Yet even this remarkable exhibition is not sufficient to satisfy a female flame bowerbird. Should a female show initial interest, the male must react immediately. Staring at the female, his pupils swelling and shrinking like a heartbeat, he begins a dance best described as psychotically sultry. He bobs, flutters, puffs his chest. He crouches low and rises slowly, brandishing one wing in front of his head like a magician’s cape. Suddenly his whole body convulses like a windup alarm clock. If the female approves, she will copulate with him for two or three seconds. They will never meet again.

male flame bowerbird is a creature of incandescent beauty. The hue of his plumage transitions seamlessly from molten red to sunshine yellow. But that radiance is not enough to attract a mate.