To address the other side of the debate, let's focus again on the autism spectrum disorders (ASD). When the more generic "autism" was first officially diagnosed by Leo Kanner in 1943, the causative factor was chalked up to cold and unloving mothers. This theory was perpetuated until the 1960s and '70s when Bernard Rimland founded the Autism Society of America and the Autism Research Institute.
With his help -- and with the publication of the DSM-III -- the stigma previously associated with autism slowly started to lift. More parents felt comfortable coming forward and seeking psychological treatment for their children.
But it's still unclear whether the destigmatization of ASD accounts for the jump in cases, or if other factors that more recently entered the scene are causing an actual rise. Many people suspect there are contributing causes that have developed in the past few decades because the rate of diagnoses appears to be growing drastically.
Some researchers, however, suspect something else is going on, and point back to the DSM again. Asperger's syndrome was added to the list of mental illnesses in 1994 with the publication of DSM-IV -- an addition that correspondingly broadened autism into a spectrum disorder with many more levels of severity and symptoms. Since then, some studies have found that diagnoses of other conditions such as developmental language disorders concurrently decreased over the same period that ASD has appeared to be on the rise [source: Science-Based Medicine]. According to these studies, instead of an increase, it was simply a trade-off.
So while the exact cause of ASD remains tantalizingly out of reach, it's entirely possible that psychological labeling practices are to blame for the so-called explosive epidemic of these disorders. But at this point, very little has been entirely ruled out -- there could still be some instances of unnatural increases with as-yet-undetermined environmental or genetic causes. As for other childhood mental illnesses, it seems possible overdiagnosis or shifting diagnosis could be the issue as well, but that's probably a question that needs to be addressed on a case-by-case basis.