Antecedents of depression in children and adolescents.

Depression in children and adolescents is a growing health problem in the 21st century. There is growing evidence that depression poses a significant risk in the developmental trajectory of children and adolescents. It is important to identify the antecedents of depression in this vulnerable group of individuals so as to develop specific and effective preventable techniques and strategies. In this brief review, we have tried to highlight the specific antecedents of childhood and adolescence depression on which evidence is available in a structured manner. Antecedents identified in childhood and adolescent depression were categorized into biological factors, temperament, cognitive vulnerability, family factors, sociodemographic factors, academic factors, changing social milieu, school factors, and peer group influence along with the emergence of the recentproblem of excessive social networking use. Biological and psychosocial factors are equally important in the development of depression in this age group. Antecedents of childhood and adolescence depression can be targeted both to prevent and intervene depression in this population.

The existence of depressive illness in children was not known until 1970s as it was a thought that children are incapable of experiencing depression because of immature personality structures.[1] Similarly, adolescent depression was considered as developmental variation or difficulty, which they outgrow in due course of time. However, it is now widely accepted that depression is common in childhood[2] and in adolescence with several consequences if unrecognized and untreated. Current psychiatric diagnostic and classificatory systems (ICD-10/DSM-5) do not suggest any different criteria for the diagnosis of depression in children and adolescents.

Research in the last two decades had demonstrated that the manifestations of depression in children and adolescents are not always like adult depression. Studies were done in the area of neurobiology and psychosocial factors have revealed interesting leads to the fact that adult depression has its basis in experiences in childhood.[3] The onset of mood/anxiety disorders in children has been reported as early as 5 years.[4] However, if explored properly, one can also find behavior as depressive equivalents even in toddlers and infants such as inconsolable crying, refusal to feed, inadequate growth despite good nutrition, and no detectable medical comorbidity, irritability, restless behavior, etc.

There are several factors that contribute to or influence the occurrence of depression among children and adolescents, which could be considered as antecedents. In the present article, major established antecedents of childhood depression are highlighted and critically evaluated. The reason for studying antecedents is important because of these salient points listed below:

One of the most well-documented facts about depressive mood, syndromes, and disorders is that they often cooccur with other symptoms and disorders

Comorbidity of depression and anxiety disorders is estimated at 30%–70%[5]

The overlap between depression and conduct disorders is also high, estimated at 10%–35% in children and adolescents[6]

High incidence of personality disorders has been reported among depressed adolescent patients[7]

Eating disorders and substance abuse also frequently cooccur with depression.[89] At least in girls, poor body image may lead to eating disorders and then to depression

Risk of suicide-A high proportion of suicide attempters are depressed, at least after the attempt.[10] Depressed mood appears to be a strong predictor of suicidal ideation[11]

High rates of academic decline and problematic behaviors at school. Problems in peer relationships and teacher-student bond

Deficits in interpersonal functioning are thought to produce poor relationships between parent and child as well as between romantic partners[12]

Depression may make one vulnerable to medical illness

More somatization and abnormal illness behavior can also develop in depressed child/adolescent[13]

Immature development of personality and self-esteem along with poor coping skills.

FACTORS/ANTECEDENTS OF CHILD/ADOLESCENT DEPRESSION

Childhood and Adolescence is a phase of life characterized by change in every aspect of individual development as well as in every major social context.[14] The biological changes that occur in childhood and in puberty as well as the changes in the socioenvironmental milieu (related to the move from elementary to secondary school) play a significant role in one's psychological make-up. In the current literature review, a web-based search of all relevant literature was done. Search engines, such as PubMed, Google Scholar, APA PsycNET, etc., were used to extract the relevant articles. Keywords used were adolescents, children, depression, risk factors and antecedents. After obtaining essential literature, findings were analyzed, and prominent features were compiled for the review. The following factors can be considered as the antecedents of depression in children and adolescence.

Biological factors/genetic factors

Temperament

Cognitive vulnerability

Family factors

Sociodemographic factors

Academic stress

Changing social milieu

School factors

Peer group and social networking.

Biological factors/genetic factors

Family genetics

It's a well-known fact that affective disorders tend to run in families.[15] The lifetime risk for major depression in children of depressed patients has been estimated to range 15%–45%. The risk is more in cases where both parents had mood disorder associated with early onset and recurrences.[16] The genetic loading for childhood and adolescent depression has been found to be higher than that of adult-onset depression.[17] Studies have also shown that identical twins are more vulnerable to show concordance for depression than fraternal twins.[18] Earlier onset of depression is predictive of more frequent and severe depressive episodes.[19]

Molecular genetic studies

The promoter activity of the serotonin transporter (5-HTT) gene has been in the limelight recently in the molecular genetics studies on depression. More particularly, the short (S) allele in the 5-HTTLPR is associated with depression. Few studies had evaluated the above association in children and observed an excess of the SS-genotype and of the S-allele among depressed children. The family-based results suggested that the S-allele was preferentially transmitted to depressed children.[20]

Biomarkers

Research on the biomarkers in depressed adults had demonstrated that there is evidence of increased cortisol levels[21] and decreased brain-derived neurotropic factor (BDNF) levels. However, there are some contradictory reports such as low cortisol, no change in BDNF levels and decreased serum levels of polyunsaturated fatty acids and folate levels in depressed children and adolescents.[2223] This suggests that the hypothalamic-pituitary axis changes in children and adolescents during stress and depression may be slightly different when compared with adults.

Temperament

It has been postulated that the dimensions of temperament may have a predictive specificity for later psychopathology.[2425] Some researchers have also found out that those children who are fearful and subdued, had earlier very low threshold to become aroused in their infanthood, suggesting temperamental predictors of anxiety in children.[26] In addition, it has also been seen that children with internalizing disorders had low scores on adaptability and approach/withdrawal suggesting the link between behavioral inhibitions and internalizing disorders.[27] Further, a population-based longitudinal study on Cloninger's psychobiological temperamental model has revealed that there is an increased risk to development of depression in those children who had temperamental dimensions of shyness with strangers, sentimentality, and persistence.[28]

Recent studies on temperament and its association with major depressive episode (MDE) had demonstrated that a difficult temperament predicted greater frequency of lifetime MDEs and had also suggested that parental depression moderated the relationship between offspring difficult temperament and severity of MDEs. Those children with low rhythmicity and adaptability have been found to be associated with greater number of lifetime MDEs.[29] A positive association between maternal antenatal anxiety and negative infant temperamental traits has also been reported.[30] This area of research is ongoing and is expected to bring about new findings in the future.

Cognitive vulnerability

Cognitive vulnerability is an erroneous belief, cognitive bias, or pattern of thought that predisposes an individual to psychological problems.[31] The vulnerability exists before the symptoms of a psychological disorder appear and after the individual encounters a stressful experience, the cognitive vulnerability shapes a maladaptive response that increases the likelihood of a psychological disorder.[32] Studies have shown that adults and adolescents who have a cognitive vulnerability are more likely to develop depressive symptoms and disorders when they experience negative life events than are individuals who do not show this vulnerability.[33] On the other hand, adolescents show dramatic increases in cognitive ability and reasoning capacity.[34] Increased capacity to reflect on the developing self and the future is thought to play a role in the possibility of experiencing depressed mood.

Children may not have the cognitive capacities necessary for developing a stable cognitive schemas and longitudinal and cross-sectional analyses by age indicates that the vulnerability-stress interaction may only predict depression in children older than 11 years of age.[35] These studies suggest that it may be easier to alter a child's developing cognitive vulnerability before age 11. Many authors have further postulated that cognitively based interventions should be focused on this subgroup of children as intervening before they develop cognitive vulnerability and before depression rates begin to rise may be an optimal time to create resilience.[36]

Family factors

Family interactions in which there are conflicts, feelings of rejection, less expression of affect and more problems with communication have been related with childhood depression.[3738] Maladaptive parent-child interactions and marital conflicts have been linked with earlier onset and chronicity of depressive symptoms in children and adolescents.[39]

Parental divorce also appears to amplify behavioral disturbances and depression in adolescents.[40] Marital discord and economic hardship lead to higher incidence of depression in adolescents. Studies evaluating the relationship between stressful life events (bereavement, family disruption) and childhood depression have demonstrated shown a modest but significant relationship between the two.[41] Childhood maltreatment (physical, emotional and sexual abuse) and neglect poses a significant risk for the development of insecure attachment, poor emotional and behavioral self-regulatory skills, lowered cognitive functioning, poorer adaptation to school, and language delays.[42]

Sociodemographic factors

Social and economic factors along with psychosocial and genetic factors, also play a role in developing symptoms of mental ill-health in adolescents.[43] Social factors, such as low parental education, low occupational class, living in a single-parent home or having unemployed parents, are likely to increase mental distress and increase the risk of depressive symptoms among children even in societies with a strong welfare system.[44] Similarly, most of the existing studies on adolescent population have found at least one indicator of low SES (based on parent or family information), linked to the risk of depressive symptoms.[45]

Academic stress

In today's competitive society, one of the most commonly encountered stressors encountered by children and adolescents is stress due to studies. Nowadays' children try to compete more and try to excel in studies. Parents due to their high expectations, strictly monitor hours of study of their children and set unrealistic goals for them which further lead to stress and anxiety. Current generation parents usually perceive their children's academics as a matter of prestige and pride resulting in a comparison of their children's performance with others and thinking it could act as a motivating force for their own children to aim higher. However, it has been seen that many children are unable to cope with the increasing burden of studies and often feel overloaded with academic stress. Children are unable to express their problems and often land into emotional problems. In case of adolescents, there is a tendency to follow unhealthy coping strategies (like using substance-tobacco/cannabis smoking secretly) leading to various behavioral problems. The outcome of these stressful experiences has been linked with emotional problems (depression, anxiety, and dissociative disorders) and behavioral problems (externalizing disorders, aggression) of childhood and adolescents.[4647]

Changing social milieu

Rapid urbanization, industrialization and acculturation have brought about a tremendous change in the Indian family system. It has been noticed that children belonging to different socioeconomic status encounter different problems during their formative years of development. While the children from low socioeconomic status are vulnerable to physical abuse, child labor, and substance abuse, the children belonging to middle and upper socioeconomic status face different set of problems pertaining to either lack of adequate attention from their working parents or to high expectations by their parents in the growing competitive modern world. The demands of urban living and rapid industrialization are such that both parents tend to remain outside their home for a substantial period of the day.[48] It has also be seen that there has been decrease in social connectedness and shifting of emphasis from intrinsic goals such as social relationships, bonding and community participation to extrinsic goals such as money, status, etc., in children and adolescents leading to a rise in psychopathology.[4849] Studies have reported an increase in anxiety disorders among children and college students over the last decades[50] mostly in developed countries and developing countries undergoing rapid industrialization.[51]

With the advancement of media, science and technology, the needs of children and adolescents have also changed. The focus of the new generation children have been shifted to video games, i-pads, laptops, smartphones, mobiles, game-parlors and demand for outdoor unhealthy foods which was not the case 10–15 years before.[47] Hence to meet all these new demands of children, both the parents, have to work harder with a view of attaining economic independence and maintaining a higher standard of living which in turn has led to the deterioration in the quality of interpersonal interaction in the family.

School factors

The academic grades of both adolescent boys and girls appear to decrease when they have depression.[52] Studies have reported that young boys who were depressed and who engaged in minor delinquent activities had sharp grade declines.[53] Boys with no depressive episodes and no delinquent activities showed stable achievement over the course of adolescence. However, no such association has been demonstrated in girls.

School change frequently occurs during the adolescence period. Both boys and girls who went through puberty before or at the same time they moved from elementary to secondary school reported more depressed affect than adolescents who went through puberty after their school transition.[21]

Peer group and social networking

Peers play a major role in the life of children and adolescents. They form the immediate social environment after family with whom the child/adolescent can discuss freely his/her problems. Low peer popularity among adolescents is related to depression and depressive symptoms.[54] It has also been seen that less closeness with a best friend, less contact with friends, and more experiences of rejection contributed to increases over time in depressive affect.[55] Close peer relationships appear to be a protective factor for depression, particularly when parent relationships are impaired in some way.[56] Poor peer relationships constitute a risk factor for depression in early adolescence.[57]

Technological advances and social networking through the Internet (e.g., Facebook, Twitter, and cell phones (e.g., text messaging, Whatsapp) have become quite popular among the adolescent boys and girls and had resulted in creation of virtual peer network.[58] Maintaining social contacts through social networking sites is associated with greater social connectedness and well-being.[59] Subsequently, it has also been seen that children and adolescence indulging in excess use of Internet and social networking sites are more prone of developing mood symptoms[60] and greater usage predicts increases in depressive symptoms.[61] Studies have also highlighted the negative consequences of social networking usage in adolescents in the form of risky internet behaviors such as cyberbullying, unwanted exposure to pornography, and potentially revealing personal information to sexual predators.[62]

SUMMARY AND CONCLUSIONS

Several developmental pathways appear to conglomerate for depression during childhood and adolescence. Environmental events through disruption in the social fabric of a child/adolescent's life may trigger biological dysregulation. Depression might result from a series of events and processes, including genetic susceptibility, biological insults, temperament and other individual characteristics, environmental events, developmental changes, and coping responses available to the individual. Antecedents of childhood and adolescence depression can be targeted both to prevent and intervene depression in this population.

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Conflicts of interest

There are no conflicts of interest.