My son has a retained Moro. His OT worked on reintegrating it (and his other retained infantile reflexes), and it is reduced now, but still present. At least now we've gotten to the point where the sound of plastic packaging being opened doesn't send whatever he has in his hands flying.
I think there is a definite association between retained reflexes, anxiety, and sensory integration issues, but I would be reluctant to say that some were causes and others effects. I think it is just as likely that they all simply reflections or manifestations of the same difference in the underlying neurology.
ETA: To my knowledge, the first time he ever fell asleep on his own without being physically held still was when he was 8 YEARS old.
