The reason for this is that many criteria traditionally used to identify reading disabled learners are not valid for the adult learner population. Discrepancy between reading level and aptitude. Mainstream social and educational background. Prior educational classifications are not useful either. In some cases, this may be an important consideration.
Psychological effects can be positive for some learners and negative for others.
For example, some may be relieved to know why they have had so much difficulty in learning to read. And, too, the label might be used as an excuse by either learners or their teachers.