Cognitive Disorders are a group of disorders that are caused by deficits in a person’s cognition. Cognition is the interplay between memory, emotion, language (both expressive, and receptive), processing of external stimuli (visions, sound, touch etc) and orientation.
Some mental illnesses can lead to cognitive deficits. For example, people with Schizophrenia can experience cognitive regression leading to a cognitive deficit that impairs day to day function.
Cognitive disorders can be temporary or permanent depending on the cause. Even if the disorder is permanent (e.g. dementia) the progression and course can sometimes be delayed leading to a better quality of life.