Autistic disorders are often diagnosed in childhood
Campaigners are calling for better support for people affected by autism in Scotland.
The National Autistic Society (NAS) has published a report which suggests that many people are missing out on benefits.
Little over half those surveyed said there were appropriate facilities in their area.
And there were calls for those working with sufferers to receive specific training.
Robert McKay, NAS's national co-ordinator for Scotland, said: "People with autism spectrum disorders continue to find themselves
doubly excluded, first as a result of their social and communications impairments and then because support services are not designed or equipped to effectively meet their needs.
"The Scottish Executive has started to address this exclusion, particularly for children, but more needs to be done.
Families affected by autism in Scotland need more and better support to help them access their full range of rights and entitlements
NAS national co-ordinator
"An urgent priority is autism awareness training and job-specific training in autism for all professionals working with this group.
"Families affected by autism in Scotland need more and better support to help them access their full range of rights and entitlements."
The MAS report was published on Sunday to mark Autism Awareness Week, which starts on Monday.
According to the report, more than a third of carers said they did not understand the benefits system and 53% had problems filling out claim forms.
Almost two thirds said they faced difficulties securing support from social services, while 35% were dissatisfied with the support they receive.
Many people said they were unable to find a social worker who they felt understood their needs.
Some 54% of those surveyed said they had appropriate play and leisure facilities in their area, while only 9% said they had been given social skills training.