Where the boundaries are set determines how prevalent a disorder is 'discovered' to be in the population. These mental conditions appear to meet DSM's definition of mental disorder, yet they are not in the manual and are generally not considered as disorders. On this count, the DSM definition is too broad to be valid. But what is unexpectable is often a direct function of our knowledge and ability to accurately predict events, not merely an attribute of a syndrome. The unexpectable clause, if taken seriously, would exclude as disorders some of the conditions that are already included in the manual as disorders.
Depression is an expectable response to major loss.
Anti-social behavior can be an expectable response to socialization into a criminal subculture. PTSD has become the label for identifying the impact of adverse events on ordinary people. This means that normal response to catastrophic events often have been interpreted as mental disorders. In truth, we can do without the concept of neurosis. For there is no actual illness that exists as a tangible entity to which the term refers and the diagnosis has no valuable implications for prognosis or treatment.