The Effects Of Pubertal Development On Adolescent Emotional Susceptibility

Puberty is a very important turning point in individuals' life river.In this special period,adolescents are faced with changes and stress from many aspects.For example,the physiological stress brought by the changes of hormone level and other physiological characteristics;the stress from their body image concerns;the gender role stress from social environment;the interpersonal stress in the process of interpersonal communication;the stress from the conflict with their parents;the academic stress from school and parents,etc.Under these stress,adolescents are prone to a variety of emotional disorders,such as anxiety,depression and so on.Epidemiological studies have consistently shown a prompt rise of emotional disorders in adolescents when they enter into puberty,and this phenomenon is particularly significant in girls.Thus,we can infer that puberty has an important impact on adolescents' emotional disorders.Various emotional disorders have impeded the social adaptation of adolescents,so it is necessary to investigate the causes and the underlying physiological basis.There is little research measuring all the stress mentioned above on adolescents in different pubertal status and different sexes.Also the standard they used for the classification of adolescents' pubertal status was not strict.Accordingly,we used the Pubertal Development Scale to measure adolescents' pubertal status.Then measured the stress in adolescents of different pubertal stages and different sexes in study one,and analyzed the stress they felt whether being different between groups.280 adolescents were selected in study one,including 130 pre-/early pubertal subjects(number of boys and girls both were 65)and 150 mid-/late pubertal subjects(number of boys and girls both were 75).All the subjects needed to finish the scales of emotion state(Beck Depression Inventory and State-Trait Anxiety Inventory),Negative Physical Self Scale,Gender Role Scale,Adolescent Interpersonal Stress Scale,Parent-Adolescent Conflict Questionnaire,Adolescent Academic Emotions Questionnaire.The results showed that the main effects of pubertal stage were significant(P<.05)in the emotion state score and all kinds of stress,and appeared as the scores of the mid-/late pubertal subjects were significantly higher than those of pre-/early pubertal subjects.This result was consistent with the prvious findings that adolescents are facing a rapid increase in the incidence of mood disorders from the start of puberty.However,this result is only an evidence in behavioral dimension,and it may be influenced by demand characteristics,such as social desirability.Also,the potential physiological basis of the rising mood disorders is still remains unclear,so it needs to carry out rigorous experimental manipulation to collect evidence of objectively physiological indexes.“Susceptibility” refers to individual's brain sensitivity to emotional stimuli.There is close relationship between emotional susceptibility and emotional disorder,the higher negative emotional susceptibility and lower positive emotional susceptibility are both likely to result in emotional disorder.We can explore the physiological basis of adolescents' mood disorder through their emotional susceptibility.Using the EMG method,Quevedo and colleagues(2009)found that puberty enhanced adolescents' defense motivation,which was proved to predict fear and anxiety.However,this study did not directly investigate the emotional susceptibility of adolescents,and the lack of behavioral and brain indexes still makes it difficult to explain the physiological basis of mood disorder.In addition,a related study in our lab showed that puberty enhanced the gamma activity in girls for negative pictures,and this result did not exist in boys.However,this study only used negative emotional stimuli,the positive emotional stimuli also should be included in our experiment because the lower positive emotional susceptibility also may result in emotional disorder.In study two,73 subjects(36 pre-/early pubertal subjects,including 19 boys;37 mid-/late pubertal subjects,including 18 boys)were selected for the ERP experiment.The deviant stimuli were emotional pictures of different valences,and the standard stimuli was the picture of a cup.Event-related potentials were recorded for highly emotional,mildly emotional,and neutral stimuli in positive and negative blocks,when 73 adolescents distinct in pubertal stages and sexes performed an implicit emotion task.Behavioral analysis showed higher positive mood ratings for pre-/early compared to mid-/late pubertal subjects,irrespective of sex and block.ERP analysis demonstrated increasing Late Positive Potential(LPP)amplitudes from neutral,MP to HP stimuli in pre-/early pubertal,but not in mid-/late pubertal adolescents.However,girls exhibited higher P3 a amplitudes during mid-/late relative to pre-/early puberty for negative stimuli irrespective of intensity;while this puberty effect was absent in boys.In addition,regardless of pubertal stage,girls exhibited a more pronounced LPP enhancement effect for HN stimuli,and a lower threshold of responding to negative stimuli in P3 b amplitudes compared to boys.These results indicated that puberty decreased the sensitivity of adolescents in both sexes to positive stimuli,and increased the sensitivity of girls to negative stimuli.In summary,puberty enhances the susceptibility to negative stress of adolescents,and decreased their susceptibility to positive stimuli.In the meantime,adolescent girls' negative bias has also significantly been enhanced with their development.These findings have revealed the reasons and physiological basis for the increase of emotional disorders in adolescents,and are help to following prevention and intervention job.Also they are important for adolescents' physical and mental health.