Solomon
Proverbs 12:25ESV·traditional attribution

Anxiety in a man’s heart weighs him down, but a good word makes him glad.

Matthew Henry Presbyterian @wholebiblehenry

Here is, 1. The cause and consequence of melancholy. It is heaviness in the heart; it is a load of care, and fear, and sorrow, upon the spirits, depressing them, and disabling them to exert themselves with any vigour on what is to be done or fortitude in what is to borne; it makes them stoop, prostrates and sinks them.

John Gill Reformed Baptist @doctorgill

Heaviness in the heart of man maketh it stoop,.... Either an anxious care and solicitude about living in the world, as the word (m) signifies; when it seizes a man's spirits, it depresses them, and keeps them down: or a fear and dread of adversity, or sorrow and grief, on account of some calamity and distress; when it gets into a man's heart, it sinks...

Geneva Bible Notes Reformed @genevanotes

Heaviness in the heart of man weigheth it down: but a good word maketh it glad. (k) That is, words of comfort, or a cheerful mind which is declared by his words, rejoices a man, as a covetous mind kills him.