Fig. 3.

Number of neurofeedback publications and registered trials per disorder group. A) Neurofeedback studies and publications. Certain studies (dark blue) were discussed in several publications and the difference is presented in lighter shade. Depression is the most investigated disorder in the field of fMRI neurofeedback, followed by addiction and neurodegenerative disorders. B) Registered clinical trials with and without published results. Clinical trials with published results are presented in light blue. The remaining registered trials (with no published results) are presented in a lighter shade. Note that one of the studies in the miscellaneous category published results from two registered clinical trials represented under Tourette’s syndrome and anxiety. Note. TS = Tourette’s syndrome; BPD = borderline personality disorder; ADHD = attention deficit hyperactivity disorder; PTSD = post-traumatic stress disorder. Neurodegenerative diseases (ND) include Alzheimer’s, Huntington’s, and Parkinson’s disease. Brain damage includes hemineglect, hemiparalysis and stroke. Anxiety includes contamination anxiety trait of obsessive–compulsive disorder, and arachnophobia. Addiction includes alcohol, nicotine, and cocaine dependence. Miscellaneous category includes publications that investigated more than one disorder. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)