Can you be diagnosed with pervasive developmental disorder by psychologist?

Yes: A child psychologist trained in the assessment of autism spectrum disorders can diagnose and treat pervasive developmental disorder.

Yes and other MD: Pervasive Developmental Disorder is part of a bigger spectrum of Developmental Disorders which include Autism. Classifications/coding is changing and most children will fall under Autism Spectrum Disorder. These are NOT diagnosed with lab work, MRI or EEG but direct observation of behaviors and screens or historical review of behaviors. Any MD or psychologist properly trained can diagnose.