Extended Abstract
1. Introduction
Increased life span and life expectancy is the consequences of the present era. Aging is a biological process that encompasses all living things, including humans [1]. One of the problems of aging period is the failure and weakness in interpersonal relations that lead to feelings of loneliness and experience of dissatisfaction with social relationships [4]. People who for some reason are unable to make a desirable relationship often experience increased anxiety, feelings of inadequacy, and isolation [7]. Maladaptive personality traits can also be related with interpersonal problems [10]. People with maladaptive personality experience problems in their interpersonal relations [11]. The inability to establish and maintain satisfying relationships with others leads to a sense of loneliness that is likely to cause a sense of deprivation which is the core of most emotional disorders [12].
2. Materials and Methods
This is a descriptive correlational study with cross-sectional design. This study was approved by the Welfare Organization of East Azerbaijan Province and Islamic Azad University of Tabriz in Iran. Study population consisted of all elderly people living in Tabriz, Iran in 2017. The sample size was 300 persons. By eliminating confounding data, 294 questionnaires were entered into statistical analysis. Inclusion criteria for samples were having age 60 years and over, ability to communicate, lack of acute physical problems, willingness and consent to participate in the study. Exclusion criteria were unwillingness to continue participation and returning incomplete questionnaires. A purposive sampling technique was used for recruiting participants. After obtaining informed consent from participants, questionnaires (the Personality Inventory for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Brief Form (PID-5-BF) [16] and the 32-item Inventory of Interpersonal Problems [18]) were completed by them. Collected data were analyzed in SPSS V. 32 software using descriptive (mean, standard deviation) and inferential statistics including Pearson correlation test for examining the relationship between variables, Kolmogorov-Smirnov test for testing the normality of data distribution, and multiple regression analysis to investigate the relationship between response variables and predictor variables).
3. Results
Participants were 48 men (16.3%) and 245 women (83.3%) aged 60-99 years (Mean age, 68±8.45). Most of them had low literacy (n=220, 74.8%); a few of them had college education (n=11, 3.7%). There was a significant relationship between maladaptive personality traits and interpersonal problems (P<0.05). The highest significant correlation was observed between detachment and being open (r=0.51), between antagonism and being open (r=0.48), between antagonism and being aggressive (r=0.45), between psychoticism and being supportive and involved (r=0.47), between psychoticism and being open (r=0.44), and between psychoticism and caring others (r=0.44). The lowest significant correlation was found between antagonism and being sociable (r=0.19), between detachment and caring others (r=0.19), and between disinhibition and caring others (r=0.19). As shown in Table 1, the calculated F value of stepwise regression analysis of interpersonal problems based on maladaptive personality dimensions was significant (P<0.01) and indicated that these variables explain interpersonal problems. Moreover, given beta coefficients and t values, the dimensions of psychoticism (β=0.54), antagonism (β=0.33), detachment (β=0.23), and disinhibition (β=0.12) had significant effect on interpersonal problems (P<0.01), but the dimension of negative affect showed no significant association with interpersonal problems. Psychoticism and antagonism were more powerful predictors of interpersonal problems.
4. Conclusion
Maladaptive personality traits had significant effect on interpersonal problems in elderly people where psychoticism and antagonism were more powerful predictors of interpersonal problems. Given that the population of the elderly is growing rapidly throughout the world, it is therefore imperative to improve mental health indicators as well. One of the symptoms of mental health is the existence of healthy interpersonal relations. Individuals with high levels of abnormal personality dimensions often prefer loneliness even in the presence of others. These people avoid social situations and activities. 

Ethical Considerations
Compliance with ethical guidelines
This study was approved by the Welfare Organization of East Azerbaijan Province and Islamic Azad University of Tabriz in Iran
Funding
 This study did not have any funds.
Authors' contributions
Both of authors contributed in all divisions of this research.
Conflicts of interest
According to the authors, there is no conflict of interest between them.
Acknowledgements
The authors would like to thank the Welfare Organization and nursing homes in Tabriz, Iran and all participants for their valuable cooperation and support.