Autism is a developmental disorder with an early onset and lifelong duration that impairs social interaction and communication, with the condition being repeatedly diagnosed. To gain scientific knowledge about autism, one must observe these patients, perform a series of investigations and examinations, and finally obtain a general title. The first stage of getting to know children diagnosed with autism is one of the most important conditions for studying their psychology and inner world. Therefore, studying the psychology of children diagnosed with autism is also considered a responsible task for psychologists. The article presents the results of assessing the level of anxiety, stress, depression, attention and memory indicators in children with autism, which is an actual problem in recent times, in different age groups. The studies were conducted at two different locations: the Special Support, Special Training and Rehabilitation Centre (Tatvan district of Bitlis, Turkey) and the Psychological Centre Psychosocial Rehabilitation and Development Centre “PRIM” (Baku, Azerbaijan). Conducting studies in two different regions will reveal whether there is a difference between patients diagnosed with autism. The study examined children diagnosed with autism aged 6-12 years of both sexes (44 in Turkey; 51 in Azerbaijan). The results obtained in the study were compared with normal test limits. Psychological testing was conducted on an individual basis, and for the comprehensive study, the same child was tested repeatedly, with a certain frequency and with special attention. Although more boys than girls were included in the confirmed cases, since the aim was not to study gender differences, care was taken to obtain generalisable results. The attempt to clarify a complex topic such as stress in a broad topic such as autism characterises a very complex situation. Therefore, we have endeavoured to obtain more accurate results through the use of comprehensive tests. The main objective of the research work is to obtain certain results by using comprehensive psychological research methods in determining the level of stress and anxiety in children diagnosed with autism and to study the main characteristics of autism by comparing them with psychological indicators considered within the normal range. The results of studies conducted in Turkey and Azerbaijan showed the presence of low levels of attention and memory processes, behavioural disorders, aggressive and depressive behaviour in all age groups against the background of increased arousal. Children diagnosed with autism exhibit similar symptoms regardless of their geographical location, indicating that this disease has common characteristics regardless of national, racial, religious, and regional peculiarities.