Mental dis-ease is essentially universal. In more benign forms it has been called existential angst, samsara, the blues.
At the other end of the spectrum, mental dis-ease manifests behaviors that are beyond socially tolerable.
"Q-shaman" is an excellent demonstration of the dis-ease problem as explained in the Upanishads.
We almost all and always confuse our 'true-identity' (our constant-conscious-beingness) with all the wrappers of our desires and choices. Our chosen wardrobe (so to speak), is a cloak of many colors woven from our desires and experiences.
So wrapping the self, and identifying as alternative-nonfact identities results in crips and bloods, Democrats and Republicans, criminals and clergy.
What we think "I am" changes over time, youth, grown-up, mature, aged; What we think "marks me" changes, fashion, friends, opinions, desires. Changes can be slow as with aging or day-to-day fast typical of emotions (I'm so pissed off right now).
The human condition is to say, "I am...", my very existential identity is this label or that; male, female, fat, thin, pretty, homely, dull, smart, introvert, extrovert, right and you're not.
Curiously, no matter how crazy one may be, one never seems to identify as insentient.
I personally know my self as sentient and existent. All else is opinion.
I do have many labels that complete the sentence "I am...", and while the labels apply to me at moments in time, I try not to identify with the labels; they are not ME.
I was a child, I was a student, husband, father, son (both parents now dead), a bus driver, kitchen manger. I have had many roles (role-identity) but they come and go. I, the conscious center of my being, is constant and unchanging.
Dressing up is OK. It is encouraged. Variety is the spice of life and we are all other peoples entertainment.
Strutting around identifying our very existence with our ill-fitting costumes is mental illness.
The cure is knowing the "Self" that does not require any 'identities.'
That said, drugs may be needed sometimes.