Does late diagnosis lead to trauma?

I think it can, and there are a few articles online that explore how autism relates to trauma and PTSD. Compared to neurotypical people, trauma in autistic people has different causes and plays out in different ways.

Some examples: 

• Exclusion, exploitation or mistreatment by peers, leading to social phobia and mistrust of others
• Isolation
• Forcing oneself to put up with loud noises and bright light
• Pressure and criticism from parents unaware of child's underlying limitations
• Not knowing how to manage one's stress
• Forcefully masking stress-relieving behaviours like stimming 
• Suicidal thoughts in children, with no ability to rationalise or identify the root of these thoughts

Although there is a little research on the topic, I think it deserves more. I would guess that the above examples are all risk factors for depression, stress, alcoholism, heart disease, and a whole host of other health problems.