Changes in personality are common in cases of traumatic brain injury involving the frontal lobes,[1] the most famous example of this is the case of Phineas Gage who survived having a tamping iron shot through his head in a railway construction accident.
Declines from premorbid levels of intelligence and other cognitive functions are observed in stroke,[2] traumatic brain injury,[3] and dementia[4] as well as in mental illnesses such as depression[5] and schizophrenia.
[6] Other usage in psychology include premorbid adjustment which has important implications for the prognosis of mental illness such as schizophrenia.
[7] Efforts are also being made to identify premorbid personality profiles for certain illness, such as schizophrenia to determine at risk populations.
[8] In the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR), paranoid, schizoid, and schizotypal personality disorders may be diagnosed as conditions premorbid to the onset of schizophrenia.