People with autism, as well as charities and advocates, have been spreading support and awareness of the condition using the hashtag #WorldAutismAwarenessDay.

Observed on April 2, World Autism Awareness Day falls close to the beginning of World Autism Awareness Week (April 1-7).

The National Autistic Society marked the day by releasing a video explaining the condition and the symptoms that autistic people may have.

People on the autistic spectrum also took to Twitter and Instagram to raise awareness of the day.

Greta Thunberg, the 16-year-old climate activist who started the first popular school strike for climate in August 2018, posted about her experiences to mark the day.

She said: “Proud to be on the spectrum!

“Without my diagnosis, I would never have started school striking. Because then I would have been like everyone else.

“Our societies need to change, and we need people who think outside the box and we need to start taking care of each other. And embrace our differences.”

Rosie, a 22-year-old autistic woman, said: “I can say that my condition makes a lot of things in life challenging/hard to cope with, but at the same time, I wouldn’t change who I am for anybody.”

Science fiction author Elizabeth May used the day as an opportunity to answer questions from people who are unfamiliar with autism.

She said: “I am not a burden. I don’t like when people who are neurotypical tell me about my own disability. I am also not a missing puzzle piece, nor is my disability a superpower, or intended to be ‘inspiring’ for people.”

May, who lives in Edinburgh, told Press Association: “I’m tweeting about World Autism Awareness Day because I think it’s important for people who are autistic to make their voices heard.

“There’s so much misinformation about autism, and a lot of literature and articles are written either by groups who speak about autistic people in dehumanising terms, or by the parents of autistic children. Where are the autistic people speaking for themselves?

“If there’s anything I want people to know, it’s that autism is a spectrum, and in that spectrum comes a wide range of experiences and different types of people. For more information about autism, the best place to go to is the autistic community. We’re out here living our lives.”

She also explained on Twitter that bringing along a trusted person or removing yourself from a stressful environment can be helpful for alleviating symptoms such as over-stimulation.

The National Autistic Society estimates that around 700,000 people are on the autism spectrum in the UK.

May explained that one of the ways young people with autism can cope with their diagnosis is through reaching out to the community.

‏She said: “Our culture is still struggling with autism acceptance… People look at you differently after finding out, and sometimes they say rude things, and all of that can feel isolating.

“Becoming part of the autistic community can help with that feeling of isolation, and it helps with learning to advocate for yourself and your needs.”