Hi Ruth,

I can't speak to the autism side of that question, but otherwise yes, stress absolutely leads to elevated cortisol. Looking at your and my previous research papers, I believe we're both interested specifically in maternal stress. Similarly, maternal stress absolutely leads to elevated fetal cortisol exposure, and this project aimed at elucidating the mechanism by which that happens. Specifically, my projects have looked at maternal diet as the "stressor", which leads to a myriad of programming effects on offspring, seemingly mediated by cortisol. The reason we believe cortisol is a driving force in fetal programming is because of the parallelism shown with other studies of maternal stresses (including undernutrition, heat, smoking, endocrine disrupting chemicals, etc.), which all show similar programming effects, in tandem with elevated cortisol exposure. Considering cortisol's ability to signal centrally, induce cellular differentiation, alter brain development, etc., it is very reasonable for you to target cortisol in studies of brain development in your studies. I would hypothesize that maternal stress induced cortisol compromises brain connectivity and increases risks of cognitive disorders, including autism.

I was wondering whether high cortisol and Noradrenaline have a recursive effect on each other. In this case considering certain types of 'ADHD' that probably need stress handling

I assume your talking about neuronal noradrenaline opposed to circulating. In that case, I'm not certain of the relationship. I imagine that literature is well established, however.

Some studies show changes in the normal circadian patterns of cortisol in children with autism. Children with autism are thought to exhibit poorly regulated negative feedback from the HPA axis. Some children with autism have an abnormal daily rhythm and / or lack of cortisol suppression in response to dexamethasone, which is usually expected to elicit a severe negative feedback response. In children with autism, the negative feedback mechanism that regulates the HPA axis may be less effective, resulting in a prolonged increase in cortisol due to activation by a stress response.

ref: Article Enhanced Cortisol Response to Stress in Children in Autism