Therapy work? The data is very strong that therapy helps people. Equally, psychiatric medication also helps people. The data is also clear for many significant emotional problems when medications and therapy are combined the effect is even more powerful.
Work? Can these things improve a life? Of course - but not always. Issues like the teamwork or lack of it in therapy are important. Also does "work" = cure, improve, fix enough? Accurate diagnosis/understanding leads to knowing how to help better, what therapeutic approach to take. Medicine may help but is unlikely to cure - yet meds may make therapy more accessible for a patient or less severe.