Dear Constantin,

The NKI enhanced dataset has the population you are looking for. http://fcon_1000.projects.nitrc.org/indi/enhanced/

They have hundreds of subjects covering a very wide age range, including the age of your subjects. 

However, I am concerned about what you are trying to do. There is quite a strong site bias in resting-state fMRI, and there is no way you will be able to tell if the differences between your controls and patient groups are related to the disease, or any details of the acquisition protocol. For any serious analysis I am afraid you would need data for controls acquired with the same protocol as your patients. 

I hope this helps,

Pierre Bellec