In 'diseases' and 'disorders' we usually think of clear and visible symptoms that disrupt physical or psychological well-being, such as fever, a stuffy nose, diarrhea, a broken arm, missing a limb after amputation, etc.

Nevertheless, many disease disorders are invisible to the environment.

Some diseases can be demonstrated by means of a blood test or medical imaging techniques, making these 'invisible diseases' tangible.

Other disorders do not remain or are difficult to objectify, which does not mean that they do not exist.

It is precisely these disorders that deserve the necessary scientific and clinical attention. Especially because, due to their invisibility, they can be extra handicapping.

Tinnitus, chronic pain, depression, burn-out syndrome, fibromyalgia, CFS, memory disorders, etc. can have a huge impact on the well-being of the person and his environment.

New neurological imaging techniques provide continuous evidence that these disorders arise and persist through a disturbance of the homeostatic effect (self-regulating action) of the brain.

The search for the common properties of these disorders provides us with a subdivision between thalamocortical dysrhythmia (e.g. pain, tinnitus, Parkinson's disease, depression, slow-wave epilepsy) and dysfunctions of the reward system (e.g.: addiction, OCD, personality disorders, etc.).

Further scientific research will undoubtedly lead to more and better subdivisions, so that better and more focused treatment methods can be applied.