PsycInfo and PsycArticles have a Thesaurus to help you find the terms that are used consistently throughout. Ebsco's tutorial on using the Thesaurus is available here.
First, do your keyword search:
Once your results are displayed, you'll see these options on the lower left:
You can select one of these by clicking in the box and clicking "update"; this will search for the overlap between the new term(s) you select and your original term:
Or click "show more" to see the complete list. If you choose multiples it will join them with OR. But they will be joined to your original term with AND.