  We derive electric dipole moment (EDM) constraints on possible new
macroscopic time reversal and parity violating (TVPV) spin-dependent forces.
These constraints are compared to those derived from direct searches in
fifth-force experiments and from combining laboratory searches with
astrophysical bounds on stellar energy loss. For axion-mediated TVPV
spin-dependent forces, EDM constraints dominate over fifth-force limits by
several orders of magnitude. However, we show that for a generic light scalar,
unrelated to the strong CP problem, present bounds from direct fifth- force
searches are more stringent than those inferred from EDM limits, for the
interaction ranges explored by fifth-force experiments. Thus, correlating
observations in EDM and fifth-force experiments could help distinguish axions
from more generic light scalar scenarios.
