When development takes a different course

Transcript

SoheeA father is scrolling through videos on his phone and stops at one from six months ago. His son, then about fifteen months old, is waving bye-bye and saying ball. And he realizes, with a little jolt, that his son hasn't done either of those things in weeks.

RyanThat moment, noticing a skill that was there and now isn't, is exactly the kind of thing the Centers for Disease Control and Prevention, the CDC, wants families to act on right away. And it's our doorway into today's topic.

SoheeWelcome to EPPP Prep, the podcast. I'm Sohee.

RyanI'm Ryan. This is the last episode in our development domain: disorders and diseases that change the expected course of development across the lifespan. We're using CDC descriptions throughout, not diagnostic manual criteria, because this knowledge area is about how these conditions change the expected course of development: onset, early signs, causes, and what helps.

SoheeLet's start broad. The CDC defines developmental disabilities as a group of conditions due to an impairment in physical, learning, language, or behavior areas. They begin during the developmental period, may affect day-to-day functioning, and usually last throughout a person's lifetime.

RyanMost begin before birth, but some happen after birth because of injury, infection, or other factors. And causes are usually a complex mix: genetics, parental health and behaviors during pregnancy like smoking and drinking, complications at birth, infections, and exposure to high levels of environmental toxins like lead.

SoheeFor some, like fetal alcohol spectrum disorders, we know the cause. For most, the CDC says, we don't. And the CDC notes developmental disabilities occur among all racial, ethnic, and socioeconomic groups.

RyanA few causal links the CDC highlights. Some of the most common known causes of intellectual disability are fetal alcohol spectrum disorders, genetic and chromosomal conditions like Down syndrome and fragile X syndrome, and certain infections during pregnancy.

SoheeAnd low birthweight, premature birth, multiple birth, and infections during pregnancy are associated with increased risk for many developmental disabilities.

RyanNow autism spectrum disorder. The CDC describes it as a developmental disability caused by differences in the brain. People with autism often have problems with social communication and interaction, and restricted or repetitive behaviors or interests.

SoheeAnd the developmental timing is the key exam content. Autism begins before age three and can last throughout life, though symptoms may change. Some children show symptoms within the first twelve months. In others, symptoms may not appear until twenty-four months or later.

RyanAnd here's our father's video. The CDC says some children with autism gain new skills and meet milestones until around eighteen to twenty-four months, and then stop gaining new skills or lose skills they once had.

SoheeSome early signs on the CDC's list. Not responding to their name by nine months. Using few or no gestures by twelve months, like not waving goodbye. Not pointing to show you something interesting by eighteen months.

RyanAnd restricted or repetitive behaviors, like lining up toys and getting upset when the order changes, repeating words or phrases over and over, which is called echolalia, or getting upset by minor changes.

SoheeRisk factors the CDC lists: having a sibling with autism, certain genetic or chromosomal conditions such as fragile X syndrome or tuberous sclerosis, complications at birth, and being born to older parents. It's also over three times as common among boys as girls.

RyanAnd one thing that isn't a cause. The psychology textbook explains that large-scale epidemiological research has shown vaccines don't cause autism, and several of the original studies claiming a link were retracted. One retraction involved a lead researcher with a financial conflict of interest.

SoheeDiagnosis. There's no medical test, like a blood test. Doctors look at behavior and development. Autism can sometimes be detected at eighteen months or younger, and by age two, a diagnosis by an experienced professional can be considered reliable. Yet many people aren't diagnosed until much later.

RyanAnd the CDC's bottom line: research shows early intervention services can greatly improve a child's development.

SoheePause and think. Back to the father. His son lost words and gestures he used to have. Should the family wait to see if they come back?

RyanNo. A loss of skills is a reason to act now. Talk to the child's doctor and ask about developmental screening. And since the child is under three, the family can call the state's early intervention program for a free evaluation, without waiting for a doctor's referral or a diagnosis.

SoheeNext, ADHD, attention-deficit hyperactivity disorder. The CDC calls it one of the most common neurodevelopmental disorders of childhood. It's usually first diagnosed in childhood and often lasts into adulthood.

RyanChildren with ADHD may have trouble paying attention, controlling impulsive behaviors, or may be overly active. And the CDC describes three presentations: predominantly inattentive, predominantly hyperactive-impulsive, and combined.

SoheeDevelopmentally, symptoms can change over time, and might increase when the demands of daily life increase. And they can look different in adults.

RyanCauses are unknown, but genes play an important role. Other possible risk factors include exposure to lead during pregnancy or at a young age, alcohol and tobacco use during pregnancy, head injuries, and family environment.

SoheeTreatment. In most cases, ADHD is best treated with a combination of behavior therapy and medication. But for preschool children, ages four to five, behavior therapy, particularly training for parents, is recommended as the first line, before medication is tried. That's a classic exam point.

RyanFetal alcohol spectrum disorders, or FASDs. A group of conditions that can occur in a person exposed to alcohol before birth. Effects can be lifelong, including problems with behavior and learning, and physical problems. And they're preventable if a developing baby isn't exposed to alcohol.

SoheeSigns can include hyperactivity, difficulty with attention, poor memory, learning disabilities, and physical features like a smooth ridge between the nose and upper lip, called the philtrum. Fetal alcohol syndrome is the most involved end of the spectrum.

RyanAnd the CDC notes diagnosis is hard, because there's no medical test, and conditions like ADHD can have similar symptoms.

SoheeCerebral palsy, or CP. A group of disorders affecting a person's ability to move and keep balance and posture. The CDC calls it the most common motor disability in childhood. It's caused by abnormal brain development or damage to the developing brain.

RyanTwo developmental points. CP doesn't get worse over time, though symptoms can change across life. And the main early sign is a delay in reaching motor milestones, like rolling over, sitting, standing, or walking.

SoheeAlso worth knowing: people used to think CP was mainly caused by a lack of oxygen during birth. Scientists now think that causes only a small number of cases. Most CP, eighty-five to ninety percent, is congenital, meaning the brain difference or damage happened before or during birth.

RyanDown syndrome. A genetic condition in which a person has an extra copy of chromosome twenty-one. The CDC says it's the most common chromosomal condition diagnosed in the United States, and that it often brings developmental challenges, like being slower to learn to speak.

SoheeAbout ninety-five percent of people with Down syndrome have trisomy twenty-one, three separate copies in every cell. Risk rises with the mother's age, especially at thirty-five or older. But here's a subtle point. Most babies with Down syndrome are still born to mothers under thirty-five, simply because there are many more births among younger women.

RyanPause and think. A practice question says most babies with Down syndrome are born to mothers over thirty-five. True or false?

SoheeFalse. Risk per pregnancy rises with age, but the majority are born to mothers under thirty-five. That's a nice base-rate trap.

RyanAnd at the other end of life, dementia. The CDC defines it as a decline in mental ability that interferes with daily life, affecting memory, thinking, and behavior. Alzheimer's disease is the most common type, accounting for sixty to eighty percent of cases. Vascular dementia, from strokes or other blood-flow problems, is second.

SoheeAnd the developmental point is crucial. Though dementia mostly affects older adults, the CDC says it is not a part of normal aging. Also, some memory problems come from treatable conditions, like medication side effects, vitamin deficiency, or thyroid imbalance. So evaluation matters.

RyanRecap. Developmental disabilities begin in the developmental period, usually last a lifetime, and mostly have complex, multiple causes. Act early on any missed milestone or lost skill.

SoheeAutism: social communication differences and restricted or repetitive behaviors, beginning before three, sometimes with lost skills around eighteen to twenty-four months. Vaccines don't cause it, and early intervention helps.

RyanADHD: inattentive, hyperactive-impulsive, or combined; behavior therapy with parent training first for preschoolers. FASD is preventable. Cerebral palsy is the most common childhood motor disability and doesn't worsen. Down syndrome comes from an extra chromosome twenty-one. And dementia is not normal aging.

SoheeAnd that's the whole development domain. Thirteen episodes, from the first reflex to the last chapter of life. That's a lot of learning, and you did it.

RyanBe proud of that. Take a real break, then try a set of practice questions on development. Thanks for listening to EPPP Prep.

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