From a form of childhood schizophrenia to a spectrum of conditions, the characterization of autism in diagnostic manuals has a complicated history.

A 2013 initiative to find biological roots for mental health diagnoses still has broad appeal, but has not produced a dramatic shift in autism research.

Our concept of autism has evolved over the past 20 years, rendering redundant the diagnostic labels of Asperger syndrome and pervasive developmental disorder-not otherwise specified.

Five years after its latest revision, the manual used to diagnose autism is back under scrutiny, as evidence suggests it excludes some people on the spectrum.

Children with autism typically have four or five other conditions, such as attention deficit hyperactivity disorder, that can affect when they are diagnosed.

People on the spectrum often have subtle problems using language or making facial expressions. Pinpointing where those difficulties originate may help ease their social communication.

A diagnosis of social communication disorder only keeps people from a community and resources they desperately want and need.

We must diversify databases of reference DNA to improve our ability to interpret the consequences of genetic variation.

With a growing acknowledgement of self-awareness in people with autism, self-report questionnaires are gaining popularity in research and clinical practice.

A large dataset that catalogs the features of many brain conditions could transform the quest for biomarkers of autism.