Underresponsive

Underresponsive, also described as hypo-responsive, refers to a pattern of sensory processing in which an individual shows diminished, slowed, or delayed responses to sensory input. It is not a standalone diagnosis but a descriptive term used in discussions of sensory processing disorder and various neurodevelopmental conditions. Individuals who are underresponsive may require stronger or longer stimulation to notice or react to their environment.

Common signs and symptoms include delayed or weak responses to auditory, visual, tactile, or movement cues; slow or minimal responses to spoken language or social cues; reduced awareness of touch or pain; and a tendency to appear disengaged or spacier than peers. Some may seek out intense sensory input to reach an alert or aroused state, while others may seem unaware of bodily signals or environmental changes. Signs can vary across contexts and may be more evident in new or complex situations.

Causes and associations are multifactorial. Underresponsivity can occur as part of sensory processing disorder and may co-occur with autism spectrum disorder, attention-deficit/hyperactivity disorder, developmental coordination disorder, or other neurodevelopmental or medical conditions. It can also appear in typical development during fatigue, illness, or stress. No single cause applies to all individuals.

Assessment typically involves occupational therapy evaluations and standardized measures, such as sensory processing questionnaires and observational checklists, supplemented by information from caregivers and teachers. Differential diagnosis is important to distinguish sensory patterns from attention, learning, or mood-related factors.

Management focuses on enhancing responsiveness and safety through environmental modification, structured routines, and targeted interventions. Approaches may include sensory integration-based activities, a personalized sensory diet, slow exposure to stimuli, and strategies for caregivers and educators to promote engagement and appropriate responses. Outcomes vary with age, support, and consistency.