“ Estimating the prevalence of autism is difficult and controversial due to differences in the ways that cases are identified and defined, differences in study methods, and changes in diagnostic criteria. A recent study reported the prevalence of autism in 3-10 year-olds to be about 3.4 cases per 1000 children. [19] Autism and other ASDs develop in childhood and generally are diagnosed by age three. [20] Autism is about four times more common in boys than girls. Girls with the disorder, however, tend to have more severe symptoms and greater cognitive impairment. ”

“ AD is the most common cause of dementia among people age 65 and older. [22] Increasing age is the greatest risk factor for Alzheimer’s. In most people with AD, symptoms first appear after age 65. One in 10 individuals over 65 and nearly half of those over 85 are affected. [23] Rare, inherited forms of Alzheimer’s disease can strike individuals as early as their 30s and 40s. [24] From the time of diagnosis, people with AD survive about half as long as those of similar age without dementia. ”

“ Panic disorder typically develops in early adulthood (median age of onset is 24) , but the age of onset extends throughout adulthood. [5] About one in three people with panic disorder develops agoraphobia, a condition in which the individual becomes afraid of being in any place or situation where escape might be difficult or help unavailable in the event of a panic attack. ”