In cases like this, the usual cause is in the head of the "afflicted" person.
.. but the majority of them are just as someone else said-- "A few screws loose."
Exactly. Reminds me of the "Hip New Affliction":
Chronic Pain Syndrome 
A family member was "diagnosed" with this, so
I asked my Neurologist about it.
He said "Oh yes, it's diagnosed by:"Chronic Incompetent Physicians"
"Chronic Incompetent Diagnosticians"
"Chronic Incompetent Psychiatrists" 
Ken, AD6KA