Music shifts frontal EEG in depressed adolescents - electroencephalography

Adolescence, Spring, 1998 by Tiffany Field, Alex Martinez, Thomas Nawrocki, Jeffrey Pickens, Nathan A. Fox, Saul Schanberg

Music reduces stress (Stratton, 1992) and anxiety levels (Mornhinweg, 1992), and even enhances performance on abstract/spatial reasoning tests (Rauscher, Shaw, & Ky, 1.993). According to some researchers these effects can be attributed to music's ability to alter mood states (Mornhinweg, 1992). Music has improved mood according to self-report (Kenealy, 1988), and heart rate and systolic blood pressure have also been shown to improve (Pignatello, Camp, Elder, Thomas, & Rasar, 1989). In addition, music techniques have altered 'behavior in depressed individuals (Hanser, 1990; Williams & Dorrow, 1983). The question for this study was whether music could alter electrophysiological and biochemical measures of depression, namely right frontal EEG activation and stress hormone (cortisol) levels.

Recent studies suggest that affective states are associated with EEG patterns in the frontal region of the brain (Fox, 1991; Fox & Davidson, 1987). Specifically, left frontal asymmetry has been associated with positive affect (approach emotions) or decreased negative affect, whereas right frontal asymmetry has been associated with negative affect (withdrawal emotions) or decreased positive affect (Ahern & Schwartz, 1985; Davidson, Ekman, Saron, Senulis, & Friesen, 1990). In addition, chronically depressed adults are noted to have right frontal activation even during remission of depressed behavior symptoms (Henriques & Davidson, 1990). Elevated cortisol has also been associated with depression, and relaxation interventions have been noted to decrease cortisol levels in depressed adolescents (Field, Morrow, Valdeon, Larson, Kuhn, & Schanberg, 1992).

The present study differed from previous research in that it assessed the effects of music on chronically depressed adolescents, particularly the effects on their right :frontal EEG activation and their cortisol levels. Improved mood was expected to be accompanied by shifts in frontal EEG asymmetry, from relative right frontal EEG activation to relative left frontal EEG activation, and by decreases in salivary cortisol levels.

METHOD

Sample

Chronically depressed adolescent females (N = 28) were recruited from an adolescent clinic based on their Beck Depression Inventory (BDI) scores and Diagnostic Interview Schedule (DIS) diagnoses (adolescents receiving medication were excluded). The BDI (Beck, Ward, Mendelson, Mach, & Erbaugh, 1961) has 21 items, scored on a four-point scale, indicating the presence/absence and severity of depressed feelings/behaviors/symptoms. The DIS is a standardized diagnostic interview that addresses specific symptoms as well as their chronology, duration, and associated impairments. It has a step structure that minimizes interviewing time. Answers are coded 0 (corresponding to no), 1 (somewhat or sometimes), and 2 (yes). Reliability and validity of the DIS have been found to 'be as good as or better than other structured diagnostic interviews (Costello, Edelbrock, & Costello, 1985). The interviews were conducted by one interviewer who had received training at a national DIS training workshop. For this study, only the Affective Disorder Module was used to assess depression.

The adolescent females in this study received a DIS diagnosis of dysthymia (not major depression disorder) with recurrent episodes, and all scored above 16 (the typical cutoff used in depression research) on the BDI (mean = 28.9). They were single, ranged in age from 14 to 19 years (mean = 16.8), and were African American (65%) or Hispanic (35%) and low socioeconomic status (Hollingshead mean = 4.4). They were randomly assigned to a music group or a control group that was simply asked to relax their minds and their muscles for the same time period that the experimental group listened to music.

Measures

Behavior Observation Scale (BOS) (Field, Morrow, Valdeon, Larson, Kuhn, & Schanberg, 1992). The females were videotaped for 20 minutes before, during, and after the sessions. They knew they were being videotaped, but presumably any videotaping effects, such as increasing positive affect, would affect all three segments and both groups. The videotaped behaviors were rated on the Behavior Observation Scale by two independent raters who were trained to .90 reliability by a rater who had conducted BOS observations in two previous studies, one providing relaxation therapy for depressed adolescent psychiatric patients (Platania-Solazzo, Field, Blank, Seligman, Kuhn, Schanberg, & Saab, 1992) and the other providing massage therapy for the same types of adolescents (Field et al, 1992). The BOS rates subjects' state, affect, activity level, vocalizations, anxiety, cooperation, and fidgeting/nervous behavior on a three-point scale (low, moderate. high). Interobserver reliabilities based on Kappa coefficients ranged from .72 to .87 (mean = .77).

Depression Adjective Checklist (DACL). The DACL is a 32-item adjective checklist describing mood states. It has been used with adolescent samples and has good psychometric properties. The DACL was administered before and after the music and control sessions.