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Aim and Background: The role of behavioral inhibition and activation systems as predisposing factors in readiness for emotional and behavioral problems in adolescents has been increasingly studied in recent years. The purpose of this study was to investigate the role of these two systems in predicting the development of psychopathology in adolescents. Methods and Materials: The study population included all male and female junior high school students of Tehran. Multistage cluster sampling (with classification) was used to select 303 students (160 girls and 143 boys) from schools in 1st, 2nd and 13th districts of Tehran. The type of research design was descriptive-correlational. Participants completed youth self report questionnaire (YSR) and behavioral inhibition and activation scale (BIS/BAS). Descriptive (mean and standard variation) and inferential (correlation coefficient and regression analysis) statistical methods were used for data analysis. Findings: The results showed behavioral inhibition systems to be positively related to anxiety and somatic problems and negatively related to symptoms of attention deficit/hyperactivity disorder. On the other hand, behavioral activation systems had a positive relationship with symptoms of conduct disorder and a negative relationship with affective problems. All relationships were statistically significant. Conclusions: Our results, in agreement with previous studies, revealed that biological factors underlying behavioral inhibition and activation systems can be considered as predictive factors for emotional and behavioral problems in adolescents.

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Aim and Background: The behavioral inhibition system (BIS) and the behavioral activation system (BAS) are considered as factors to verify the effects of personality significance on cortical activity. The present study explored the effects of the BIS and BAS on frontal asymmetry in response to affect stimuli. Methods and Materials: This study included 36 individuals (18 with high BAS sensitivity and 18 with high BIS sensitivity, 17 women). All subjects were introduced to neutral, happy, and sad conditions by the International Affective Pictures System (IAPS) and brain waves were recorded simultaneously. Finally, absolute power of alpha band (8-12 Hz) of the right and left frontal areas were calculated for each participant. Findings: A mixed repeated measurements analysis of variance (ANOVA) was used to analyze the absolute alpha power. Results revealed an increased response to neutral stimuli in BAS group within the left frontal area. However, no significant effects were found in the BIS group in this condition. In addition, an increased left frontal activity (alpha decreasing) in response to happy pictures was seen in the BAS group. On the other hand, an increased right frontal activity (alpha decreasing) in response to sad pictures was found in the BIS group. Conclusions: The results were consistent with the approach/withdrawal model and cerebral asymmetry. The role of the frontal region in positive and negative moods was also approved.

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Aim and Background: High prevalence of borderline personality disorder and its harmful social, health and economic consequences highlights the importance of studying this disorder and its underlying factors. The present study aimed to investigating behavioral-brain systems of individuals with borderline disorder and its discriminative aspects of these systems in patients and healthy controls. Methods and Materials: Thus 30 patients who admitted to Razi Hospital (Tabriz, Iran), completed the behavioral inhibition system (BIS), behavioral activation system (BAS) questionnaire by Carver and White (BIS/BAS scales). Control group consisted of 30 subjects without any mental disorder history. Findings: Results from multi-variant regression analysis showed that the two groups had statistically significant differences in BAS, BIS and sensation seeking scale (P < 0.01). Among these factors, sensation seeking scale with Wilks&rsquo; lambda = 0.42 and BAS with Wilks&rsquo; lambda = 0.53 had statistically significant role in discrimination between the two groups. Conclusions: Hyperactivity of BIS caused a permanent anxiety and negative emotions experienced by borderline patients and hyperactivity of BAS could be the underlying reason of impulsivity, which is the core component of borderline personality disorder. According to other studies in the field of bio-neural factors effects in development of borderline personality disorder, this study can help to improve our understanding of disorder and therefore help to improve developing accurate methods to predict the possibility of disorder. In addition, it will help us to develop methods for primary prevention and developing more effective therapy methods.

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Aim and Background: Understanding the predictors and vulnerabilities of bipolar disorder is very important because the prevalence and recurrence rate of this disease is high and even after treatment, patients still experience mild symptoms and functional impairments. Therefore, the present study aimed to investigate the mediating role of behavioral activation system–relevant cognitive styles in the relationship between traumatic childhood experiences with bipolar disorder syndrome in patients with bipolar disorder.
Methods and Materials: The present study was a descriptive correlational study. The statistical population consisted of all patients with bipolar disorder admitted to Shahid Hayinejad Hospital in Babol. The sample size was 379 people who were selected by available sampling method in a period of 18 months. In order to collect the research data have used  from the Child Trauma Questionnaire, Beck Depression Inventory- II,  Mania Self-Report Scale and 3 Questionnaires of behavioral activation system–relevant cognitive styles (Perfectionism / Performance Evaluation subscale of Dysfunctional Attitudes Scale, Self-Criticism subscale of Depression Experiences Scale, and Autonomy subscale of Autonomy - Community orientation Scale). The research data were analyzed using SPSS and LISREL software and structural equation modeling.
Findings: The results showed that traumatic childhood experiences have an effect on behavioral activation system–relevant cognitive styles and symptoms (depression and mania) of bipolar disorder (p <0.05). Behavioral activation system–relevant cognitive styles have an effect on symptoms (depression and mania) (p <0.05). In addition, the results showed that the behavioral activation system–relevant cognitive styles mediate the relationship between traumatic childhood experiences and symptoms (depression and mania) of bipolar disorder.
Conclusions: The results of the present study support the hypothesis behavioral activation system–relevant cognitive styles mediate the relationship between traumatic childhood experiences and symptoms (depression and mania) of bipolar disorder.