A 14-year-old boy in Mexico had such an intense fear of growing up that he took extreme steps to hide or curb his growth, such as restricting his food intake and distorting his voice, according to a new report of his case.

The boy's phobia started when he was about 11 years old. He had learned that nutrients in food would cause him to grow — so he ate less, and lost more than 26 lbs. (about 12 kilograms), according to the report from the health workers who treated him.

In addition, he stooped over to hide his height, and distorted his voice so that he spoke in a higher pitch.

"Every time he notices a physical change that indicates that he is growing, he feels fear and anxiety, to the point that [he] has considered undergoing multiple surgeries to hide it," the researchers wrote in their report, published Dec. 21 in the journal Case Reports in Psychiatry. "He also believes that once he reaches [adulthood], he is more likely to get sick and die, all of which are very overwhelming." [What Really Scares People: Top 10 Phobias]

The boy's mother also treats him as if he were younger — for example, by singing him lullabies and choosing what he wears each day.

Although the boy saw a psychologist for a year, the therapy did not help, and he was referred to treatment at the Autonomous University of Nuevo León, in northern Mexico.

The researchers there diagnosed the boy with gerascophobia — an excessive fear of aging — a phobia that does not appear to be very common. Just two previous cases of gerascophobia have been reported, and both cases were in adults, according to the report.

Phobias often develop from a combination of biological, psychological and environmental factors, said Dr. Alan Manevitz, a clinical psychiatrist at Lenox Hill Hospital in New York, who did not treat the boy.

In this case, the boy experienced separation anxiety disorder (a condition in which children worry excessively when they are separated from loved ones or are in unfamiliar places) when he was 5, and he was sexually abused by a neighbor when he was 6. He was also bullied two to three times a week when he was in sixth grade. These experiences could have contributed to the development of gerascophobia, the researchers said.

Martin Antony, a professor of psychology at Ryerson University in Toronto, said he had not personally seen a case like this boy's, and he had not ever heard of a patient being diagnosed specifically with a fear of aging. Other experts, he said, might have diagnosed the boy not with a phobia, but rather another psychiatric condition — for example, body dysmorphic disorder, in which people are preoccupied with a physical characteristic that they perceive to be a defect.

"Somebody else might well diagnose this as a different problem than what the authors have," Antony said.

Dr. Luis Gonzalez Mendoza, director of pediatric endocrinology at Miami Children's Hospital, agreed. He said he thought the boy might have gender dysphoria, a condition in which a person does not identify with his or her biological gender. Patients with this disorder may fear going into puberty because they don't identify with the physical traits they are developing, Mendoza said.

Manevitz said that, for people with phobias, it is important to identify the underlying factors of the psychiatric condition, such as anxiety, panic attacks and body image problems. The boy's case was very complex, so it would require a multifaceted treatment, Manevitz said.

The boy was treated with the antidepressant fluoxetine, along with a form of psychotherapy, and family therapy.

His condition improved — he began to stand upright and speak in his natural tone of voice. His eating disorder also improved, and he gained 13 lbs. (6 kg).

"He is able to imagine the future, living on his own and working as an actor, and this is an idea he likes; however, he continues to express a fear of commitment and responsibilities that he feels will be required of him in adult life," the researchers said.

Doctors may consider a similar treatment for patients with comparable symptoms, the researchers said.

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