The simple answer is yes, even if it seems you are repeating yourself or appearing to say too much. If for example you only mention one condition for a question and the DWP doesn't accept it - then you've lost the opportunity to tell them about something else which also has an impact.
Don't assume the DWP will understand your condition/s and/or difficulties - you have to tell them and explain why. So if you can't cook a meal because of arthritis and chronic depression - you would need to explain how those two things effect your ability to cook.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems
