悩める

Etymology 1
From, as a regular shift to the conjugation pattern. Compare a similar shift for and.

First cited to 1563.

Verb

 * 1)   to vex, to annoy, to cause distress, to make someone suffer
 * 2)   to be vexed, to be bothered about something, to be distressed about something
 * 1)   to be vexed, to be bothered about something, to be distressed about something

Usage notes
Much like root verb, this derivative nayameru has been used with both transitive and intransitive senses. The transitive sense appears to be far more common.

Etymology 2
Ultimately from in the  of nayami + stative / resultative copula, in the  conjugation. See further sound-shift details at り.