Autism: Causes and Increase in Cases in California

Autism: Causes and Increase in Cases in California

The current statistic in the autism community - that the incidence of new cases in California has risen from 1 in 500 to 1 in 125 in the past 5 years has caused people to take a further look into the causes of this striking increase. On one hand, a rise in autism diagnoses doesn't necessarily mean a corresponding rise in actual cases. Doctors may be inadvertently inflating the numbers by diagnosing the disorder more readily than in previous years. Another possible consideration is that the surveys given to parents may yield unreliable results as they may have misremembered or misinterpreted diagnoses when answering [16]. However, at the same time, there is real evidence that more children are actually suffering from autism. An average of 9 new autism cases come to the state's attention every day, the vast majority in children 13 and younger. This has caused statewide officials to take action in response to the increase. In San Francisco for example, schools have been overwhelmed with new cases, causing the school district to now have three specialists to deal with the autism curriculum, as opposed just a few years ago, when there was just one. Classes for autistic students have been developed from kindergarten through to high school. The school district has provided special training in autism for at least 50 speech therapists and teachers [17].

There is little agreement about what is driving the growth of autism cases in California. Some of the theories include mercury in vaccines, genetic variability, and environmental factors [18]. Here, in this paper, we will explain what autism really is, examine a few of the theories on what causes autism, and address what may be behind the increase from 1 in 500 to 1 in 125.

What is autism?

Autism is a general term used to describe a group of complex developmental brain disorders. Autism causes the child to experience the world from a different perspective than most other children. This disorder attacks neural development by impairing social interaction and communication, which leads to restrictive and repetitive conduct. Children who have autism are normally introverted and are unable to communicate without assistance from an adult. Most autistic children are normal in appearance, but will display puzzling and disturbing behavior patterns. There is a strong genetic basis for autism, but it is not apparent if it is from rare mutations or combined common genetic variants. There are theories that autism is caused from heavy metals, pesticides, and childhood vaccines. Recently there was information released stating that autism is not caused by vaccinations, but some beg to differ.

There are different types of autism: Asperger syndrome (AS), Rett syndrome, Autism spectrum disorder (ASD), and pervasive developmental disorders (PDD). Asperger syndrome is a developmental disorder, and is distinguished by a child's obsessive behavior with a single object or topic. Rett syndrome is a rare condition that generally affects females. With this condition, the child would develop normally, and then start to develop autistic-like behavior. ASD is usually diagnosed between ages three and four. This disorder impairs social and communication skills, repetitive and restrictive type of behavior, and is more common in males. Lastly, PDD is comparable to ASD however, children vary in abilities, intelligence, and behaviors. Parents will usually notice signs of autism within the first three years of their child's life. The signs typically develop gradually, but sometimes it can be normal development and then regress. There is no known cure but some individuals are seeking to find a cure. They also believe that autism should be classified as a difference and not disorder.

Causes of autism

The causes of autism are just as complex and mysterious as the disease itself. Most autism studies focus on vaccines (which include mercury levels), genetic defects, and environmental factors. There is no known definitive cause of autism [5] [12], yet we do know that autism tends to "run in the family" [13] and is understood that it is caused by abnormalities in brain structure and/or function.. There are, however, a number of factors that may collectively contribute to autism; these may consist of environmental, genetic predisposition, vaccine-induced, and illness factors, as postnatal factors. It is worth noting, that according to the National Autism Association, no specific "autism gene" has been found [5], [6], [12].

Vaccines and Mercury

Mercury and vaccines seem to be the most controversial suggested cause of autism. The debate has been going on for years, in regards to a study released in 1998 by Dr. Andrew Wakefield. Dr. Wakefield suggested that the combined vaccine MMR (measles, mumps, and rubella) may have been unsafe. After this study was released, the vaccinations performed in Britain plummeted and it subsequently had absolutely no effect on the rise in cases of autism. This theory and study focused on the mercury levels in thimerosal, a preservative used in vaccines. After Dr. Wakefield's study was released, vaccinations stopped using thimerosal as a preservative, which also had no effect on the rise of autism cases. To this day, there continues to be no specific evidence that vaccines cause autism, or even high levels of mercury. "Study after study has failed to show any link, and prominent scientific agencies have concluded that scarce research dollars should be spent investigating other possible causes of autism." 1

A study of mercury levels in children diagnosed with autism compared to children with normal developmental tendencies has also been conducted.

The CHARGE Study is a large, comprehensive, epidemiologic investigation designed to identify factors associated with autism and discover clues to its origins. CHARGE study participants include children between 24 and 60 months who are diagnosed with autism, as well as children with other developmental disorders and typically developing controls. 2

This study focused on the amount of fish these children ate, the amount of gum they chewed, and dental amalgams. The outcome of the study showed that the levels of mercury in children diagnosed with autism and the levels of those with normal developmental behavior to be the same. Dr. Hertz-Picciotto, a researcher at UC Davis M.I.N.D Institute, said:

Just as autism is complex, with great variation in severity and presentation, it is highly likely that its