vicious
downward, upward
deflationary, inflationary
wage-price
death (AmE,figurative)
The company has entered a death spiral.

create, trigger
There is a risk that the policy may trigger an inflationary spiral.

continue
The economy continued its downward spiral.

halt, stop

spiral of
to halt the vicious downward spiral of drug abuse

Spiral is used with these nouns:
curl, dive, galaxy, notebook, stair, staircase