ESA:got sick notes for physical illness-Can I claim for my mental illness too

Hi, I've been unable to work and have been getting doctors notes for a physical illness but I also have a mental illness (which is going to be more long term problem), I'm about to pass the period where I will have to make a claim for UC/ESA (whatever it's called) and be assesed - will I need to get a sick note for the mental illess to claim for this or can I just enter the details of both the physical and mental conditions when I have to fill in the forms?

Thankyou

Thanks very much, I was just worried I wouldn't be able to mention the mental illness because I hadn't used it on the sick note. Thank you