Cognitive-Functional Intervention for Adults With ADHD (Cog-Fun-A): An Extreme Case Series Analysis

Adults with attention-deficit/hyperactivity disorder (ADHD) often experience executive dysfunction that disrupts daily routines, occupational performance, and quality of life. Occupation-based interventions such as Cognitive-Functional Intervention for Adults (Cog-Fun-A) aim to address these challenges, yet little is known about variability in engagement and outcomes. This brief report describes three contrasting cases drawn from a Cog-Fun-A pilot study. Participants completed pre-post assessments including the Behavior Rating Inventory of Executive Function-Adult Version, Canadian Occupational Performance Measure, Adult ADHD Quality of Life Scale, Self-Regulation Skills Interview, and Model of Human Occupation Screening Tool. Therapist session logs were analyzed using descriptive content analysis to construct within-case and cross-case profiles. Two participants demonstrated clinically meaningful improvements in occupational performance, satisfaction, quality of life, and self-regulation, whereas one showed minimal change. Patterns across cases suggested that motivation, attribution style, routine stability, and environmental supports may influence engagement and strategy use in metacognitive, occupation-based intervention.