What is the relationship between rejection sensitive dysphoria and ADHD? I discovered something called Rejection Sensitive Dysphoria (RSD). If you google it, the first page will show pages that talk about it in relation to ADHD.

What is it about ADHD that causes "nearly everyone with" it to have RSD?

Someone might say that ADHD people would not be sensitive to rejection because they have too many thoughts unless they're hyperfocused on such rejection.

RSD sounds like something related to anxiety rather than attention deficiency or hyperactivity. So someone may suspect that RSD belongs to people with anxiety, depression, bipolar or people with a personality disorder like borderline or narcissistic rather than to people with ADHD. I really can't think of a connection between RSD and ADHD.
Upon closer examination, it appears that Rejection Sensitive Dysphoria is a term that was coined by Dr. William Dodson to describe the phenomenon of rejection sensitivity in ADHD sufferers. It does not appear to be a 'valid' term, in the sense that there is no DSM definition. In fact, it seems that Dodson himself is the only one to have used the term. Dodson specializes in adult ADHD, and so it makes sense that the only articles associated with the term would pertain to ADHD.

As for the phenomenon of rejection sensitivity itself, note the definition of dysphoria as follows: "a state of feeling unwell or unhappy; a feeling of emotional and mental discomfort as a symptom of discontentment, restlessness, dissatisfaction, malaise, depression, anxiety or indifference."

In a broader sense, these are issues associated with chemical imbalances -- as is ADHD. One could even describe ADHD as its own dysphoria. It is also quite common for other disorders to coexist alongside ADHD, particularly anxiety, depression, obsessive-compulsive disorder and bipolar disorder. This -- coupled with the fact that children with ADHD often find themselves socially isolated -- may be responsible for a higher prevalence of rejection sensitivity in those with the disorder.



The following is an edit by the OP, Jack Bauer.

Dodson likely did not coin the term RSD, but he might have been the first to use it with ADHD. It has been used in relation to borderline people: 1 2 3 4 5