The psychological symptoms that may occur after stroke include depression, anger, aggression, anxiety, apathy, catastrophic reaction, psychosis and mania,1 of which the most common symptom is depression.2 1/3-2/3 of patients suffer from post-stroke depression, of which the main symptoms were reportedly loss of energy in 83% of patients, sleep disorder in 67%, increase of brooding in 60%, and hopelessness in 39%.3

Special attention is needed in post-stroke depression because it prevents patients from participating in active rehabilitation, resulting in the failure of rehabilitation.4 Studies show post-stroke depression attributes to the stroke itself, sequelae of stroke, risk factors of major depressive disorder, severe cognitive dysfunction and physical disability after stroke.5 Of the risk factors that predict major depressive disorder, women, family history, and past history are also reported major risk factors of post-stroke depression.6 Pre-morbid personality, in particular neuroticism, which is another risk factor of major depressive disorder, has received little attention.7,8 Relevant studies have been presented several times abroad, but there have been none in Korea.

This study was conducted to determine the correlation between pre-morbid personality and depression scales in stroke patients. Furthermore, its correlation with location of lesion, sex, functional ability, age, cause of stroke, duration of illness (months), presence of underlying disease, educational background, and history of medication for depression was also investigated.

According to the study of Robinson et al.12 in 1983 with DSM-III, post-stroke depression has 27% probability of leading to major depressive disorder and 20% to dysthymia. In the study by Astrom et al.13 in 1993, 25% of 73 patients were diagnosed with depression by DSM-III. Another study, the lowest prevalence rates were depressive disorder found in patients that studied in community settings where 14% of the patients were found to have major depression, while 9% had minor depression. In outpatient settings, which vary between 3 months and 3 or more years following stroke, the prevalence rate for major depression was 24.0%, and for minor depression was 23.9%.14 Suicide ideation or pessimism is less frequently seen than apathy, which often demotivates people, in depression.15,16

Lack of energy and depressive moods are one of the major symptoms of depression. In physical terms, cognitive dysfunction or psychological symptoms arouses, distracting people from living an ordinary life. The study conducted by Pyun and Kim17 revealed that a person's adaption of living everyday life was significantly higher when he did not suffer depression. Another study4 relating depression and the result of rehabilitation showed that depression discourages people from participating in active rehabilitation, reducing the probability of achieving the originally aimed goal of rehabilitation. Because depression is a chronic disorder, post-stroke depression is prone to occur at any time. This is problematic not only to the individual but also to the family, eventually expanding as a problem for the whole society. If post-stroke depression were predictable in advance, close observation and support may be given. Special treatment such as education of caregivers, psychological therapy and preventive medication can be also provided. Early detection and treatment of depression is important in the sense that it enables better comprehensive rehabilitation results of not only depression but also stroke.

The most widespread way to determine depression is DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition), but its drawback remains that quantitative analysis is impossible and it requires specialists. Aben et al.,18 reported that HRSD is most similar to DSM-IV and the highest sum of sensitivity and specificity, and that although BDI, HADS (Hospital Anxiety and Depression Scale), SCL-90, and HRSD differ in terms of sensitivity and specificity, they are all valid as screening tests. BDI is commonly used for its time-efficiency and a small number of questions that reduce confusion in patients.9

Depression among patients with stroke was studied in relation to its correlation with other factors. The study of Robinson et al.19 concluded that patients with damaged frontal lobe had higher possibilities of suffering post-stroke depression. Moreover, the study of Morris et al.20 agreed to this conclusion, reporting that patients with damaged left hemisphere, the frontal lobe and basal ganglia in particular, suffered more severe depression. The study of Carson et al.,21 however, suggested that the location of lesion and post-stroke depression did not correlate. The effect of gender on the diseases is also controversial. While Paolucci et al.22 maintained that patients with cerebrovascular disease are at a much higher risk, Kaji et al.23 found no statistical correlation. This study also failed in discovering any correlation of depression with the damaged part in cerebrum or gender.

Personality traits are integral and organized behaviors that characterize an individual. This refers to the reactions of an individual to diverse circumstances, specifically those with stability and consistency, making it appropriate for deduction. There are 5 classifications that show both personality traits common in most humans and differences among individuals. We conducted this study based on the Big Five Structure/Five Factor Model, which shows that the personality traits of individuals is divided largely into 5 factors.24-28

There are studies presented abroad showing that N (neuroticism), one of the 5 factors, is closely related to post-stroke depression,29-31 but there have been no studies like this in Korea. This is most likely because there are not many tests that can be used for practical medical purposes rather than mere evaluation of personality. NEO-PI10 was selected carefully among tests that fulfilled the following conditions: differentiates of the 5 personality traits, quantitative analysis is possible, has a comparatively short measuring time, is easy for those at low cognitive level to understand, and is confirmed after translated into Korean. In Korea, the translation modified into by Kang11 (N: neuroticism, E: extraversion, O: openness to experience, A: agreeableness, C: conscientiousness) (Appendix 1) was used.

NEO-PI was used in a variety of areas, studying borderline personality disorder and paranoid personality disorder had a positive correlation with neuroticism (N), schizotypal personality disorder positively correlated with neuroticism (N) and negatively correlation with extraversion (E).32 In addition, it was reported that anxiety and schizophrenia have a positive correlation with neuroticism (N), mania has a positive correlation with extraversion (E), paranoia and antisocial personality have a negative correlation with agreeableness (A).33

This is because neuroticism (N) is defined as a personality trait that accumulates negative emotions (fear, anger, frustration).10,29 High neuroticism (N) is generally associated with being emotionally anxious, displaying hostility towards others, and being sensitive to what others think.33 This contributes to making a response to the changed appearance after stroke the most depressed compared to other types of traits.

The limitations of this study included a small number of subjects which made generalization difficult. Also, there were relatively more patients with damage in the left cerebral hemisphere, which is the result of excluding patient subjects of severe cognitive and communication dysfunction. Premorbid personality was not determined by NEO-PI based on the supposition that some change would take place in the patient, but there lies the possibility that a disparity may exist between the caregivers witness and the patients real personality before stroke. It is helpful, however, in the sense that screening tests can be done when patients are hospitalized and there is active rehabilitation when neuroticism is identified through the test.

Through this study, we found that in predicting depression of patients with stroke, knowing pre-morbid personality measured with NEO-PI is more helpful than knowing age, sex, causes of stroke, location of lesion, duration of illness, presence of underlying disease, education background, usage of depression drugs, or physical viability. Furthermore, not only BDI evaluated directly by the patient but also HRSD evaluated by intimate caregivers showed the correlation between premorbid personality and post-stroke depression scale. This conclusion signifies that premorbid personality helps predict depression, and that psychological and emotional support can be designed in a more specific manner along with medical treatment. Therefore, this should be considered seriously when setting rehabilitation goals of patients with stroke.