Diagnostic overshadowing occurs when symptoms that could indicate multiple conditions are automatically attributed to an existing diagnosis rather than prompting further evaluation. This can lead to missed or delayed identification of co-occurring conditions. For example, hypervigilance commonly associated with PTSD may be interpreted solely as trauma-related arousal, overshadowing the presence of ADHD-related restlessness.

This is especially common among Autistic and ADHD people. In AuDHD, the more visible traits of one neurotype can absorb clinical attention, leaving the other under-recognized. Co-occurring mental health conditions add further layers: autistic sensory overload may be labeled anxiety, ADHD restlessness attributed to PTSD, or impulsivity folded into a bipolar diagnosis while the underlying ADHD is never assessed.

Recognizing diagnostic overshadowing allows for a more accurate understanding of a person’s experiences. By widening the clinical frame, it creates space to see strengths and challenges that may have been missed under a single label. This broader view supports more appropriate supports, accommodations, and interventions, and can also help individuals develop a more grounded sense of self-compassion, recognizing that past struggles often reflected a mismatch in support, not a personal failing.