"How can I handle tantrums with my child on the autism spectrum? How should I deal with 'meltdowns'? Should the two be treated differently? If so, how does one know the difference between the two? Sorry for all the questions... but this is all new to me. My son was recently diagnosed with autism spectrum disorder and I want to do the right thing here! Please help. Thank you." Autism Spectrum Disorders (ASD), also known as Pervasive Developmental Disorders (PDDs), cause severe and pervasive impairment in thinking, feeling, language, and the ability to relate to others. These disorders are usually first diagnosed in early childhood and range from a severe form, called autistic disorder, through pervasive development disorder not otherwise specified (PDD-NOS), to a much milder form, Asperger syndrome (now called "high functioning autism"). They also include two rare disorders, Rett syndrome and childhood disintegrative disorder. Some ASD kids are more