Appropriate analysis of data

In my study i have two groups (Patients and Healthy Controls)
In the experiment both groups do first a task [which is scored and ends up as a mean ranging from 1 to 6 (Pre Score)]. Then groups are randomised to either do an intervention or just fill in questionnaires (control). Then both groups are asked to do the same task [which is again scored and ends up as a mean ranging from 1 to 6] (Post Score)
[Pre Intervention score - Randomisation to either intervention or questionnaires (control)- Post intervention score]

What i want to find out is whether those who were in the intervention group did better (their Post score was greater than the Pre score) compared to those who did questionnaires (control) [if there was i significant difference between them].
Also i want to see if there is an analysis i can do in which i can include all groups: 1) Pre Score and Post Score 2) Intervention and Control 3) Patients and Healthy Controls.

Could you help me with which test is appropriate to use?