Variant Connective Tissue

Researcher has shown that many people with chronic pain, chronic fatigue, hypermobility (like EDS), autism, ADHD, and dysautonomia (such as POTS) often experience more than one of these conditions. Scientists are now trying to understand why.

One possible explanation is connective tissue. Connective tissue is found throughout your body—in your joints, blood vessels, skin, digestive system, and even around nerves. In people with hypermobility or connective tissue disorders, this tissue works a little differently.

Because connective tissue supports the autonomic nervous system (the system that automatically controls things like heart rate, blood pressure, digestion, temperature, and breathing), differences in connective tissue may make this system less stable. This can contribute to dysautonomia.

Another piece of the puzzle is interoception, which is your brain’s ability to notice what’s happening inside your body—things like your heartbeat, breathing, hunger, pain, or temperature. Many autistic and ADHD individuals process these internal body signals differently. If the autonomic nervous system is already more reactive because of connective tissue differences, those internal signals may become even stronger or harder for the brain to regulate.

Research has found that adults with joint hypermobility are much more likely than the general population to have autistic or ADHD traits. In one study:

• Nearly half (47%) screened positive for autistic traits.

• About 1 in 5 (20%) screened positive for ADHD traits.

Researchers also found that people with chronic pain or chronic fatigue were significantly more likely to have autistic or ADHD traits. Importantly, joint hypermobility explained part of this relationship, suggesting that connective tissue differences may be one of the biological links connecting these conditions.

Even more interesting, the more features of connective tissue differences someone has, the more likely they are to report neurodivergent traits. This suggests these conditions may not simply occur together by chance—they may share some of the same underlying biology.

In simple terms:

If your body’s connective tissue is built a little differently, it affects not only how your joints move, but also how your autonomic nervous system functions and how your brain receives and processes signals from your body. That combination can increase the likelihood of hypermobility, dysautonomia, chronic pain, fatigue, autism, and ADHD occurring together.

Researchers are still studying exactly how these connections work, but growing evidence suggests these conditions are interconnected rather than completely separate diagnoses. Understanding those connections may help clinicians treat the whole person instead of addressing each condition in isolation.