On the metacognitive deficit:
“Evils of the soul escape most people; for this reason they are worse—they prevent those who suffer from sensing them”
τὰ δ᾿ ἐν ψυχῇ λανθάνει τοὺς πολλοὺς κακά, διὰ τοῦτ᾿ ἐστι καίω, προσαφαιρούμενα τὴν αὑτῶν τοῦ πάσχοντος αἴσθησιν
This and the following passage are from Plutarch’s On Whether Sickness of the Body or Mind Are Worse (Moralia 500 ff). The following (especially the last line of the first paragraph) appears to perpetuate the stigmatizing of mental illness. And it does: many behaviors we today would see as parafunctional and requiring therapy, ancient authors viewed as issues of will.
“Just as, therefore, the storm which keeps you from docking is more dangerous than the one that won’t let you sail, the storms of the soul are worse when they do not allow a person to control or put down his troubled thoughts—this person goes without a helmsman, without ballast in confusion and wandering, taking off in steep and opposite courses until suffering a harrowing shipwreck and crushing his life. This is why it is worse to suffer sickness of mind than the body: For those who are sick, merely suffer; the sick of mind suffer and harm others.
But why is it necessary to repeat the great number of afflictions? Current events remind me of them. Do you see this immense, mix up crowd which clings together and mixes around the seat of government and the market?”
Ὥσπερ οὖν ἐπισφαλέστερος χειμὼν τοῦ πλεῖν οὐκ ἐῶντος ὁ κωλύων καθορμίσασθαι, οὕτως οἱ κατὰ ψυχὴν χειμῶνες βαρύτεροι στείλασθαι τὸν ἄνθρωπον οὐκ ἐῶντες οὐδ᾿ ἐπιστῆσαι τεταραγμένον τὸν λογισμόν· ἀλλ᾿ ἀκυβέρνητος καὶ ἀνερμάτιστος ἐν ταραχῇ καὶ πλάνῃ δρόμοις λεχρίοις καὶ παραφόροις διατραχηλιζόμενος εἴς τι ναυάγιον φοβερὸν ἐξέπεσε καὶ συνέτριψε τὸν ἑαυτοῦ βίον. ὥστε καὶ ταύτῃ χεῖρον νοσεῖν ταῖς ψυχαῖς ἢ τοῖς σώμασιν· τοῖς μὲν γὰρ πάσχειν μόνον τοῖς δὲ καὶ πάσχειν καὶ ποιεῖν κακῶς συμβέβηκε.
Καὶ τί δεῖ τὰ πολλὰ λέγειν τῶν παθῶν; αὐτὸς ὁ καιρὸς ὑπόμνησίς ἐστιν. ὁρᾶτε τὸν πολὺν καὶ παμμιγῆ τοῦτον τὸν ἐνταῦθα συνηραγμένον καὶ κυκώμενον ὄχλον περὶ τὸ βῆμα καὶ τὴν ἀγοράν;