I saved the best for last.
Without a doubt if you are following a well developed treatment plan with consistency and you either plateau in your progress or see no change then an assessment of potential infection or dysbiosis need to occur.
Infection involves a pathogen that has the potential to cause disease.
Dysbiosis is an imbalance of commensal bacteria that if certain strains overgrow can cause inflammation, biofilms and other local symptoms. These organisms are typically not pathogenic but can be the cause of disease and dysfunction.
In my line of questioning I am always checking for mould exposure, parasite infections, small intestinal bacterial overgrowth, commensal fungal overgrowth, intestinal pathogens, previous Ebstein Barr infections (often resulting in mono), Lyme disease, H. pylori and chronic sinusitis or recurrent sinus infections.
If a functional assessment confirms the presence of infection then this becomes the number one treatment target before moving forward typically looking at a least a 3 month period before symptoms resolve.