Depression Literature Review

Introduction

Adolescence is a fundamental stage for self-development that involves numerous emotional, biological, and sociological changes for students. While many students successfully navigate this stage without major psychological disorders, adolescence can be a stage of increased vulnerability. In 2009, nearly 30% of adolescents had moderate to severe depressive symptoms, many of which have the possibility to develop into severe depression in adulthood (Falci & McNeely, 2009). After a student beings a depressed trajectory, the likelihood that the individual will continue along this course increases due to self-withdrawal tendencies, minimizing social support networks (Petersen et al., 1993). This literature review will examine predictors and trends in research of adolescents with depressive symptoms.

Prior Symptoms

The majority of research studies concluded that prior depressive symptoms were a consistent predictor of later depressive symptoms in adolescents and in adulthood. Researchers established that prior depressive symptoms explained as much as 80%-90% of the reliable variance in data, leaving a small margin of influence by other predictors on current levels of depression (Cole, Girgus, Paul, and Nolen-Hoeksema, 2006). Two longitudinal studies were completed with differing sample sizes; Study 1 included 708 participants; Study 2 included 508 participants. Researchers tested the hypothesis that results would support both the Stress  Depression model (SD) and Depression  Stress model (DS). Results indicated that depressive symptoms in adolescents were influenced by a stable trait factor and a less stable state factor (Cole et al., 2006, p. 40). Cole et al.'s (2006) established that the relation between stress and depression is reciprocal and noted that previous studies with a singular model being observed were incomplete without the inclusion of a second model (p. 40). Limitations of the study include exclusion of a third variable, such as parental depression, which could influence both the SD and DS models (Cole et al., 2006). Findings of the study implicate the need for further research utilizing a third variable and a reciprocal model of stress and depression.

Another study, the Oregon Adolescent Depression Project, using a prospective design and a randomly selected sample of 1,710 adolescents (14-18 years of age), assessed whether past occurrences of depression were associated with current depressive disorders. Results included that a history of depression does represent an elevated risk for developing depressive disorder (Lewinsohn, Roberts, Seeley, Rohde, Gotlib, and Hops, 1994). Lewinsohn et al.'s study maintained that previous depression in adolescence can also predict a variety of negative life events in adulthood (1994). Limitations of the study include the lack of subgroups to evaluate comorbidity, fair levels of reliability of psychosocial measures, and inclusion of participants with both major depressive and dysthymic disorder. Strengths of the study include a large representative community sample size and the generalizability of results. Overall implications include a small margin of influence by other predictors and prior depression as a predictor.

Parent-Adolescent Relationships

Another predictor of depressive symptoms in adolescence is a parent experiencing depressive disorder. The majority of community and clinical study samples indicated that depression is inversely related to the level of support received from family members (Sheeber, Davis, Leve, Hops, and Tildesley, 2007, p. 144). Specifically, father-adolescent relationships in families with depression reported lower levels of support and higher levels of conflict when compared to the control group (Sheeber et al., 2007, p. 151-152). Sheeber et al. (2007) maintained that the negative effect of conflictual father-adolescent relations appeared stronger than mother-adolescent relations. Limitations of the study include its cross-sectional design and the difficulty in determining the extent to which high/low levels of parent-adolescent conflict were associated with depressive symptoms. Despite limitations, these results suggest that family-based practitioners could tailor interventions for students with these relationship characteristics.

A second longitudinal study collected multi-method data and examined patterns of behavioral interaction among adolescents' relationships with parents and peers. Community samples of 143 adolescents were assessed using observational and peer-report methods. Participants were assessed at age 13 and again for a followed-up 1 year later. Allen et al. (2006) observed difficulty in adolescents in attaining autonomy and frequently exhibited relationships with peers that were "withdrawn, angry, or demonstrated a dependent pattern of behavior" (p. 55). The study hypotheses were confirmed and dysfunctional interaction patterns with parents and peers were found over time as predicted (Allen et al., 2006, p. 55). Limitations of the study include a narrow developmental period focus, the exclusion of fathers in the study, and the inability to establish causal relations from results. The findings indicated that targeting specific behavior patterns of adolescents with depressive symptoms in psychosocial interventions may be beneficial.

Self-Esteem

Low self-esteem (negative self-evaluation) was a predictor for developmental difficulties in adolescence and negative outcomes in adulthood. In a thesis on depressive disorder and self-focused negative evaluation, Lall states that negative self-evaluation is a fundamental element of depression (1990). Lall (1990) maintained that when individuals display self-focused attention, without meeting internal performance standards, negative self-evaluations become likely (p. 2). While the thesis project failed to demonstrate differing levels of self-focused attention, variations in standards and evaluations of participants were analyzed. Findings indicate that depressed participants evaluated themselves more negatively than did non-depressed participants (Lall, 1990, p. 25). Additional research exploring the effects of negative self-evaluation could be beneficial, as research on negative self-evaluation was not extensive.

Alternative studies established that negative self-evaluation and low self-esteem was a predictor of poor mental health. Researchers conducted a prospective longitudinal study over an 11-year time span and controlled for shared method variance. Self-esteem was measured in 978 participants at ages 11, 13, and 15 using a Self-Esteem Scale. Trzesniewski (2006) established that low self-esteem in adolescent may be a predictor of negative consequences during