Fifty-one youth athletes (n = 27 female, age = 14.53 years, SD = 1.85) presented to a local hospital outpatient concussion clinic on average 7.67 days postconcussion for standard medical assessment, including the self-report Sport-Concussion Assessment Tool-2 (Time 1). They completed follow-up symptom assessments at Time 2 (7.48 ± 1.24 days after Time 1) and Time 3 (7.63 ± 1.42 days after Time 2). We assessed the relations between theoretically relevant personal and situational variables, assessed at Time 2, and concussion symptom reports at Time 2 and Time 3. Using hierarchical regression, we also assessed relations between personal/situational factors and changes in symptom intensity from Time 1 to Time 2, Time 1 to Time 3, and Time 2 to Time 3, controlling for Time 1 postconcussion symptom intensity, age, gender, concussion history over the past 12 months, and the number of days since sustaining the current concussion. Controlling for these factors, the combined influence of the psychosocial factors predicted 43% of the variance in symptom expression at Time 3. Psychosocial factors also accounted for 27% of the variance in symptom change from Time 1 to Time 2, and 23% of the variance in symptom change from Time 1 to Time 3. Athletic identity, performance anxiety, and amotivation were the most consistent and influential person variables, each being related to more intense symptom reports and slower recovery. Results suggest the potential importance of psychological factors in concussion recovery.