Psychotic symptoms from methylphenidate can include hearing voices, visual hallucinations, urges to harm oneself, severe anxiety, mania, grandiosity, paranoid delusions, confusion, increased aggression, and irritability.
His writings were characterized as nonsensical, abounding in self-glorification and grandiosity, replete with histrionics and hysterical, incontinent outbursts.
Though sometimes inclined to indulge in grandiosity when writing for a full symphony orchestra, he was adept in using smaller forces to the maximum effect.