If anger is fear in armour, then what works on fear is what works on anger: go towards the thing in small doses, stay a little longer each time, and let your body collect evidence.

What the research says

Across mixed anxiety and depressive diagnoses, difficulty tolerating uncertainty was elevated at the start of treatment, fell during it, and its reduction was associated with better outcomes, which supports working on a shared process rather than a label. Separately, in a cohort of 103 veterans, high anger at intake predicted poorer response to trauma treatment nine months later. Both are observational in part, so they point the direction rather than prove the route.

Strength of evidence: one line of research. A single study, or a theoretical account.