Barbara,
Good start to the discussion. Since you are correlating two variables (beliefs and feelings) you’ll need a separate scale to measure each. If you take from the same scale, likely the variables are already correlated as that is part of scale development and then you would lose the gap. Another and better option is to separate your IV into groups (ADHD vs Non ADHD) and then use the Attitudes towards Mental Health Problems Scale to see if there are differences between these groups.
Please respond to this.