This is the text from Maddening Darkness:
Magical darkness spreads from a point you choose within range to fill a 60—foot—radius sphere until the spell ends. The darkness spreads around corners. A creature with darkvision can’t see through this darkness. Nonmagical light, as well as light created by spells of 8th level or lower, can't illuminate the area. Shrieks, gibbering, and mad laughter can be heard within the sphere. Whenever a creature starts its turn in the sphere, it must make a Wisdom saving throw, taking 8d8 psychic damage on a failed save, or half as much damage on a successful one.
This is the text from Darkness:
Magical darkness spreads from a point you choose within range to f ill a 15-foot radius sphere for the duration. The darkness spreads around corners. A creature with darkvision can’t see through this darkness, and nonmagical light can’t illuminate it.
If the point you choose is on an object you are holding or one that isn’t being worn or carried, the darkness emanates from the object and moves with it. Completely covering the source of the darkness with an opaque object, such as a bowl or a helm, blocks the darkness.
If any of this spell’s area overlaps with an area of light created by a spell of 2nd level or lower, the spell that created the light is dispelled.
Maddening Darkness doesn't specify that you can cast the spell on an object, but it uses the same wordage "from a point you choose within range". Can you interpret this to mean that Maddening Darkness can also be cast on an object?