According to the Diagnostic and Statistical Manual of Mental Disorders released by the American Psychiatric Association, axis 1 and axis 2 are the first two groups of this classification. Axis 1 disorders are mental disorders without the inclusion of mental retardation or personality disorder. The various mental disorders that are grouped under axis 1 are Substance-Related Disorders, Schizophrenia, and Other Psychotic Disorders, cognitive disorders such as dementia, delirium, amnestic.
Others are eating disorders, dissociative disorders, anxiety disorders, sleep disorders, factitious disorders, etc. On the other hand, axis 2 houses all kinds of personality disorders and mental retardation. The various mental disorders that are grouped under axis 2 include Schizotypal Personality Disorder, Narcissistic Personality Disorder, Paranoid Personality Disorder, Obsessive-Compulsive Personality Disorder, Antisocial Personality Disorder, Histrionic Personality Disorder. While axis 1 disorders are correctable, though, with time, axis 2 disorders are very hard to correct. This is because most of them are conditions from childhood.