Characteristics of adolescent girls with depressive symptoms in a so-called "normal" sample

Abstract

Objective: Forty-four percent of adolescent girls who had been screened for absence of psychiatric disorder reported depressive symptoms on a structured interview. Girls reporting symptoms were assigned to a depression group and compared to those who were free of depressive symptoms on behavioral and neuropsychological measures to determine if there were meaningful differences in cognition, behavior and motivation/self-perception between groups. Method: Adolescent girls were randomly selected from local schools to participate in a study of neuropsychological development in adolescence. Those who volunteered and whose parents reported them to be free of psychiatric disorders were enrolled and completed a battery of behavioral, neuropsychological and motivation/self-perception measures. Results: The depressed group showed more behavioral problems, evaluated themselves as less competent, showed more extrinsic motivational orientation, had lower IQ and differed on a measure of visual spatial perception. Conclusion: The frequency of subclinical depression is high in adolescent girls, even when parents report no psychiatric/emotional problems. The increase in problem behaviors and extrinsic motivation, as well as the decrease in feelings of self-worth suggest that this group may benefit from intervention. Poorer performance on a measure of visual spatial perception needs further investigation to confirm its association with depression and understand its relationship to depressive symptoms.

Introduction

As many as ten percent of adults have met DSM-III-R criteria for Major Depressive Disorder (MDD) within a given twelve-month period (Kessler et al., 1993). The disorder is also diagnosed with increasing frequency in adolescents, among whom prevalence rates for current MDD are estimated to range from 0.4 to 6.4 percent (Fleming and Offord, 1990). Females are at particular risk for the disorder; numerous studies document higher rates of depression in adolescent and adult females than males (for reviews see Weissman and Klerman, 1985Weissman et al., 1984). Leon et al. (1993), for instance, found a nearly doubled risk for MDD in females in recent decades, with first onset most common in late adolescence or early adulthood. Additionally, Lewinsohn et al. (1993)found a lifetime prevalence of 22.3% in adolescent females, age 14 to 18 years and 11.4% in adolescent boys. Female adolescents have been found to be at increased risk for more severe and prolonged depressive episodes than their male peers (McCauley et al., 1993).

Research suggests that prevention of adolescent MDD episodes is possible when populations at elevated risk for the disorder are targeted for psychosocial interventions (Beardslee et al., 1992, Clarke et al., 1995). Promising outcomes have been obtained in programs developed for children of depressed parents (Beardslee et al., 1992) and adolescents with subclinical depressive symptomatology (Clarke et al., 1995). Identification and treatment of individuals in the latter category is of particular importance, as more than 50% of first episodes of MDD occur in individuals who have had prior depressive symptoms (Horwath et al., 1994).

Little is known about subclinical depression in adolescents, however, despite estimated prevalence rates as high as 46% for boys and 59% for girls (Roberts et al., 1990). Most research regarding depression in this population has focused on behaviors and features associated with MDD (Kovacs et al., 1984McCauley et al., 1993Kashani et al., 1980Carlson and Cantwell, 1980Mitchell et al., 1988Puig-Antich and Rabinovich, 1986Deykin et al., 1987Harter, 1989Marton et al., 1993Ryan et al., 1987). Gotlib et al. (1995)compared false positive (subjects with depressive symptoms but not meeting criteria for major depression), with true-positives and true-negatives on measures of clinical and psychosocial functioning. False-positive and true-positive participants did not differ on most measures of psychosocial dysfunction.

Cognitive deficits, particularly in memory (Burt et al., 1995) and visuospatial/visuomotor skill (Cassens et al., 1990) have been well documented in adults with MDD. Less research, however, has examined cognitive correlates of MDD in younger populations and the majority of existing work has focused on preadolescent children rather than adolescents. Lewinsohn et al. (1994a)found no relationship between vocabulary level and depresssion in adolescents, which is consistent with findings of minimal associations between depression and verbal skill in children (Kaslow et al., 1983, Kaslow et al., 1984) and adults (Cassens et al., 1990). Several studies have revealed statistically significant, but modest correlations between severity of depression and IQ in preadolescent children (Lefkowitz and Tesiny, 1985, Tesiny et al., 1980), however, no significant differences in IQ have been revealed in comparisons of depressed and nondepressed children. MDD in children is associated with poorer performance on measures of attention, coordination and psychomotor speed (Kaslow et al., 1983Kaslow et al., 1984). Memory deficits are less evident than in depressed adults; in a study of inpatient and outpatient 9–12 year olds, Lauer et al. (1994)found immediate recall deficits on the Children's Auditory Verbal Learning Test in a severely depressed MDD/dysthymia group relative to less depressed MDD/dysthymia and non-depressed children. The less depressed group earned the highest scores on this measure, which led the researchers to hypothesize that memory impairment in childhood depression varies as a function of symptom severity with only the severely depressed exhibiting memory impairment. Thus, although verbal knowledge is preserved in depressed adolescents, little is known about other cognitive characteristics of MDD or subclinical depression in this age group.

Low self-esteem is a well-documented feature of MDD in adolescents (Harter, 1989, Marton et al., 1993, Ryan et al., 1987). Inpatient depressed adolescents have been found to differ significantly from normal adolescents on measures of self-perceived behavioral conduct and global self-worth. Additionally, the severity of depression correlated negatively with self-perception of social acceptance, romantic appeal, close friendships and global self-worth (King et al., 1993). In a normal sample of young adolescents, Renouf and Harter (1990)found a significant negative relationship between global self-worth and depressive affect.

Few studies have examined relationships between motivational orientation and depression, and we could find no research addressing such relationships in adolescents. Children with extrinsic motivational orientations (those who perform tasks for reasons external to the individual such as grades), however, have been found to experience more depressive symptomatology than those with an intrinsic motivational orientation (those who perform tasks for the inherent pleasure of mastery) (Boggiano and Barrett, 1992). In the same study, girls were found to be more extrinsically motivated than boys, and thus more vulnerable to feelings of helplessness and depression. Boggiano and Barrett (1992)also cite an unpublished study in which they found similar relationships between extrinsic motivation and depressive symptomatology in college students.

MDD in adolescence has been closely examined and characterized. A similarly thorough understanding of the features of subclinical depression is important for several reasons. First, because of the association between subclinical depressive symptomatology and future development of MDD, a thorough description of cognitive and behavioral features associated with subclinical depression in adolescence may aid in early identification of those at risk. Second, information about subclinical depression may help provide a better understanding of the nature of MDD as a syndrome, particularly whether it is of a continuous or dichotomous nature.

We have been engaged in a study of neuropsychological development in normal adolescent females. Potential participants were screened for the presence of psychopathology to eliminate the potential confound of neuropsychological deficits associated with depression. Individuals with no history of diagnosis with or treatment for a psychiatric disorder were enrolled in the study. Participants were subsequently administered a more thorough psychiatric interview and several self-report questionnaires to confirm the absence of disorders. During the evaluation process, we found that an unexpectedly large number of participants (44% of the total sample) reported current or past depressive symptoms. Of this subgroup, however, only two participants exhibited symptoms of sufficient severity to warrant referral for further evaluation or treatment. In light of the lack of research describing characteristics associated with subclinical depression and of cognition in depressive disorder in adolescence, we elected to study these participants' patterns of cognition, self-perception and motivation. Differences, if found, would hold important implications regarding the nature of depressive disorders, as well as for research on normal populations.