What the evidence says, including where it is thin
Two things, and the second one includes its own correction.
The first is why the marker at the top of this lesson is where it is. Personal debt is associated with suicidal thinking, and that finding is the reason a course about money has to handle risk at all rather than treating it as a lighter topic than the ones about mood.
The second is about treatment for the worry itself. Psychological treatment for generalised anxiety produces substantial improvement compared with control conditions. And the authors are clear that those effects shrink when the comparison is an active treatment rather than a waiting list, and that lower quality trials inflate them. We would rather publish the shrinkage than the headline. It is the honest version, and it is a more useful thing to know before you start.
What the research says
Meltzer H, Bebbington P, Brugha T, Jenkins R, McManus S, Dennis MS (2011). Personal debt and suicidal ideation. Psychological Medicine, 41(4), 771 to 778 doi
Personal debt was associated with suicidal thinking in a national survey population. This is the reason a course about money worry carries risk markers at the top of its final lesson rather than at the bottom.
Cuijpers P, Sijbrandij M, Koole S, Huibers M, Berking M, Andersson G (2014). Psychological treatment of generalized anxiety disorder: a meta-analysis. Clinical Psychology Review, 34(2), 130 to 140 doi
Psychological treatment produced substantial improvement in anxiety compared with control conditions. The authors flag that the effects are inflated by lower quality trials and by comparisons against waiting lists, and that they shrink when measured against an active comparison.