Also known as neurotherapy or biofeedback, neurofeedback is a form of biofeedback which provides feedback in real time from the brain to help improve healthy brain function. Electrical activity from the brain is collected via sensors placed on the scalp using electroencephalography (EEG), with feedback presented using video displays or sound. The evidence supports neurofeedback as a treatment for many mental disorders including anxiety, depression and PTSD. It has been in practice for almost five decades. NFB is not invasive and does not use drugs. It is usually a multi-session option that takes around a month to complete. Approximately 80% of neurofeedback sessions produce positive and long-lasting results. This is impressive, especially when "mainstream" treatment options have failed.