Excerpted from De proprietatibus rerum 7.5

Madness (amentia) is the same as mania (mania), according to Platearius [Practica brevis, II.6 (Venice edition)]. Mania, in turn, is an infection of the anterior section of the cerebrum, with loss of imagination, just as melancholy is an infection of the medial section of the cerebrum, with loss of reason, as Constantine says in his book, On melancholy. Melancholy, he says, is suspicion ruling the mind, brought on by fear and sadness. These emotions differ based on the various kinds of harm they do to [normal] functioning; in mania, it is the imagination which is principally damaged, while in the other [melancholy] it is the reason.

Original Latin

Et generantur hae passiones aliquando ex cibis melancholicis: aliquando ex potatione fortis vini, exurentis et incinerantis humores; aliquando ex animae passionibus, scilicet solicitudine, tristitia, nimio studio, timore; aliquando ex morsu rabidi canis sive alterius animalis venenosi; aliquando ex corruptione aeris pestiferi et infecti; aliquando ex malitia humoris corrupti, dominantis in corpore hominis ad talem infirmitatem praeparati.

Secundum autem diversas causas diversa sunt signa. Nam quidam clamant, saltant, se et alios vulnerant, et in latebris latitant, de quorum dispositione et differentia supra habitum est, libro 5, ubi agitur de cerebri passione.

Horum medicina est ut ligentur, ut a propria vel aliena cessent laesione, maxime sunt tales recreandi, et a solicitudinis et timoris causa et materia amovendi, et instrumentis musicis laetificandi, mediocriter exercitandi, et tandem si purgationes et electuaria non sufficiunt, arte chyrurgica sunt curandi.