The brain is special: it computes. Which computations the brain is able to perform is determined both by its biology but also by the history of computations the brain has performed. An inability by the brain to compute adaptive solutions to the problems it faces can therefore give rise to mental illness both through mechanisms akin to those in other areas of medicine, such as cellular dysfunctions, but also through the consequence of “ill-learning,” for instance, after traumatic events. This line is blurry: illness can obviously give rise to ill-learning and ill-learning to illness, eg, through substance abuse often seen after trauma.