I've noticed a few things and I'd like to discuss and have feedback on some of them here.
I've been through depression and Generalised Anxiety Disorder, these are two I guess I will have to deal with as long as this body is alive. Anyway, I've noticed a few links between IEs and these corresponding disorder.
Major Depressive Disorder: weakens Te, Se, Fe, Ne. Tends to strengthen Fi, Ni, Si, Ti. (these are considered on my observation of myself, which may not apply universally since I'm delta ST). Notice here all Introverted IEs have been strenghthened, and all Extrovert IEs have been weakened.

Anxiety disorder tends to weaken Fi, Ni. Basically I see Ni on egoblock people dealing better with Anxiety in general than Sensors and Ne on egoblock people (Add IJ temperament to this list). Si helps a lot with coping Anxiety, but then if it's paired with Te such as in delta ST, it becomes a battle between: relaxing and letting go and feeling at peace at ease which I relate to Si; and working and doing things and producing which I relate to Te.

Anxiety in myself also strenghtens Se to a point where I become very much bothering to others due to excess Se and lack of Fi. It also tends to weaken Feeling IEs in me. I become much colder, harsher and in a hurry for doing things, taking little consideration of others' will and often pushing them to my command. And then a panic episode happens - usually when I'm waking up from sleep. And it's like a warning - I must cool down or I'll go insane. Then Si comes into foreplay and it's a nice IE for me to deal with Anxiety. But then my tendency is to submerge myself in Si and then it becomes, after a week or so, depression. It's a vicious circle.

I wonder are these observations just from myself or could they be held as general rules for every type?