What explains sensory sensitivity in some adults with ADHD?

Sensory sensitivity is very real in ADHD, even though it is not always highlighted in diagnostic criteria. From a neurobiological perspective, ADHD involves differences in how the brain filters and regulates incoming information. Dopamine and norepinephrine help the brain decide what to amplify and what to ignore. When that filtering system is inconsistent, sensory input like noise, light, textures, or movement can feel too loud, too sharp, or impossible to tune out. Many adults with ADHD are not more sensitive in the sensory organs themselves. The difference is in processing. The brain has a harder time dampening background input, so everything arrives at once and with equal intensity. This can lead to overwhelm, irritability, fatigue, or shutdown, especially in busy or unpredictable environments. Sensory sensitivity also interacts with emotional regulation. When the nervous system is already taxed by stress, fatigue, or cognitive effort, tolerance for sensory input drops further. What feels manageable on a calm day can feel unbearable on a depleted one. Clinically, we often see adults who were labeled as picky, dramatic, or anxious when in reality they were coping with unrecognized sensory overload. Many learn to mask or push through until burnout makes the sensitivity impossible to ignore. This does not mean something is wrong with you. It means your nervous system processes input differently. Supporting sensory needs through breaks, noise control, movement, or environment changes is not indulgent. It is regulation. Understanding this piece often brings a lot of self compassion and relief.