the ideal would be to test the personality before a big traumatic event happens (earth quake, Estonia catastrophe, tsunami and so on) and then to test it afterwards.The personality is likely to change after a trauma.
Here's a study using the CPI: Chronic trauma effects on personality traits in police officers.
doi: http://dx.doi.org/10.1002/jts.22089
By Leigh Wills, Jennifer; Schuldberg, David
Journal of Traumatic Stress, Mar 8 , 2016, No Pagination Specified.
The impact of cumulative occupational exposure to traumatic events (TEs), posttraumatic stress (PTS) symptoms, and work environment stress on personality traits over time was examined in 38 police officers from an urban agency. California Psychological Inventory (CPI) personality trait scores from prehire evaluations were compared with follow‐up CPI scores to test whether exposure to traumatic events was correlated with changes in traits from baseline to 5–10 years later. Measures of occupational TEs, PTS symptoms, and police work environment stress were administered. Mean trait scores declined on all CPI traits analyzed in the study. Trait change was evaluated using the Reliable Change Index; change in participants’ scores unlikely to occur by chance ranged from 11% to 63% in the traits examined. All participants reported substantial TE exposure. PTS symptoms were correlated with steeper decline in 4 of 5 traits, with effect sizes ranging from r = −.47 to r = −.67. Scores on measures of job‐related TEs were negatively correlated with only one CPI trait (empathy) at T2 (r = −.31), and were unrelated to slope of trait change. Work environment stress was significantly related to gender, with female officers reporting higher levels of operational (r = .45) and organizational (r = .54) stress. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
Personality changes are sure for there in Un fixed traits 40% responsible for training, learning, handling present situations/ task .. on the other hand fixed traits ( 60 % of persons mind) responsible for the major traits which can not be changed.
Writing samples over a period of time records all the personality traits changes, addition... It is like personality trait album ( similar to photo album of person).
Handwriting is instant pen picture of writing so it captures all the changes,, improvements in personality traits.
Based on your question regarding deep personality trait changes, I'd recommend that you read into the NEO-PI-R. As a measure it is very well accepted by personality psychologists and it draws on the five factor model of personality.
However I'd note that to my understanding it doesn't address personality change. You'd have to measure participants at multiple intervals in a longitudinal design in order to determine what the baselines were and if there were any significant changes. Assuming that you observed significant changes over time, there'd be no way of explaining why there were changes using just this measure though.