Watson and Clark (1991) proposed the Tripartite Model of Anxiety and Depression to help explain the comorbidity between anxious and depressive symptoms and disorders.Anderson, E., & HOPE, D. (2008). A review of the tripartite model for understanding the link between anxiety and depression in youth. Clinical Psychology Review, 28(2), 275-287. doi:10.1016/j.cpr.2007.05.004 This model divides the symptoms of anxiety and depression into three groups: negative affect, positive affect and physiological hyperarousal.Clark, L., & Watson, D. (1991). Tripartite model of anxiety and depression: Psychometric evidence and taxonomic implications. Journal of Abnormal Psychology, 100(3), 316-336. doi:10.1037/0021-843X.100.3.316Brown, T., Chorpita, B., & Barlow, D. (1998). Structural relationships among dimensions of the DSM-IV anxiety and mood disorders and dimensions of negative affect, positive affect, and autonomic arousal. Journal of Abnormal Psychology, 107(2), 179-192. doi:10.1037/0021-843X.107.2.179 These three sets of symptoms help explain common and distinct aspects of depression and anxiety.
The ability to distinguish between anxiety and depression with this model may help increase diagnostic accuracy and help eliminate the complications that occur with comorbidity.Gaylord Harden, N., Elmore, C., Campbell, C., & Wethington, A. (2011). An examination of the tripartite model of depressive and anxiety symptoms in African American youth: Stressors and coping strategies as common and specific correlates. Journal of Clinical Child and Adolescent Psychology, 40(3), 360-374. doi:10.1080/15374416.2011.563467Kendall, P., Kortlander, E., Chansky, T., & Brady, E. (1992). Comorbidity of anxiety and depression in youth: Treatment implications. Journal of Consulting and Clinical Psychology, 60(6), 869-880. doi:10.1037/0022-006X.60.6.869 According to Clark, depressed patients have a comorbidity rate of 57% for any anxiety disorder.Mineka, S. (1998). Comorbidity of anxiety and unipolar mood disorders. Annual Review of Psychology, 49, 377. doi:10.1146/annurev.psych.49.1.377 Other studies in youth have revealed comorbidity rates of anxiety and depression as high as 70%.Zahn Waxler, C. (2000). Internalizing problems of childhood and adolescence: Prospects, pitfalls, and progress in understanding the development of anxiety and depression. Development and Psychopathology, 12(3), 443-466. doi:10.1017/S0954579400003102 There are many negative effects of anxiety-depression comorbidity.Brown, C. (1996). Treatment outcomes for primary care patients with major depression and lifetime anxiety disorders. The American Journal of Psychiatry, 153(10), 1293. doi:10.1176/ajp.153.10.1293 The negative effects of comorbidity include: chronicity, recovery and relapse rates, and higher suicide risk. Among youth samples, negative effects of anxiety-depression comorbidity include: increased substance abuse, more likely to attempt suicide, receive a diagnosis of conduct disorder, and are less likely to show favorable gains from treatment.
Factors Negative affect
Negative affect is the factor that is common to both anxiety and depression. Negative affect can be defined as, "the extent to which an individual feels upset or unpleasantly engaged, rather than peaceful". It involves negative mood states such as subjective distress, fear, disgust, scorn, and hostility.Watson, D., Clark, L., & Carey, G. (1988). Positive and negative affectivity and their relation to anxiety and depressive disorders. Journal of Abnormal Psychology, 97(3), 346-353. doi:10.1037/0021-843X.97.3.346 Mood states that are specific to depression include sadness and loneliness that have large factor loadings on negative affect. Some common symptoms of negative affect include: insomnia, restlessness, irritability, and poor concentration.
There is a substantial amount of empirical research on negative affect (NA) and its role in the tripartite model. For example, the Mood and Anxiety Symptom Questionnaire (MASQ) was administered to a sample of college students and a sample of psychiatric patients. The correlations between the specific anxiety scale (anxious arousal) in the MASQ and NA were moderate (rs= .41 and .47), supporting that NA is specific to anxiety disorders, congruent with the tripartite model. Another study consisted of a sample of children (ages 7–14) diagnosed with a principal anxiety disorder. The children completed the Positive and Negative Affect Scale for Children (PANAS-C). The results showed NA was significantly associated with measure of anxiety and depression. A study by Chorpita in 2002, was consistent with the tripartite model. In a large sample of school-aged children, NA was positively correlated with all anxiety and depression scales.
Physiological hyperarousal Physiological hyperarousal is defined by increased activity in the sympathetic nervous system, in response to threat.Gencoz, F. (2000). Physiological hyperarousal as a specific correlate of symptoms of anxiety among young psychiatric inpatients. Social Behavior and Personality, 28(4), 409. doi:10.2224/sbp.2000.28.4.409 Physiological hyperarousal is unique to anxiety disorders.Hughes, A., & Kendall, P. (2009). Psychometric properties of the positive and negative affect scale for children (PANAS-C) in children with anxiety disorders. Child Psychiatry Human Development, 40(3), 343-352. doi:10.1007/s10578-009-0130-4 Some symptoms of physiological hyperarousal include: shortness of breath, feeling dizzy or lightheaded, dry mouth, trembling or shaking, and sweaty palms.Watson, D., Clark, L., Weber, K., & Assenheimer, J. (1995). Testing a tripartite model: II. exploring the symptom structure of anxiety and depression in student, adult, and patient samples. Journal of Abnormal Psychology, 104(1), 15-25. doi:10.1037/0021-843X.104.1.15Laurent, J., Catanzaro, S., & Joiner, T. (2004). Development and preliminary validation of the physiological hyperarousal scale for children. Psychological Assessment, 16(4), 373-380. doi:10.1037/1040-3590.16.4.373
Compared to negative affect and positive affect, physiological hyperarousal has been studied less.Chorpita, B., Daleiden, E., Moffitt, C., Yim, L., & Umemoto, L. (2000). Assessment of tripartite factors of emotion in children and adolescents I: Structural validity and normative data of an affect and arousal scale. Journal of Psychopathology and Behavioral Assessment, 22(2), 141-160. doi:10.1023/A:1007584423617 Chorpita et al. (2000), proposed an affect and arousal scale in order to measure the tripartite factors of emotion in children and adolescents. In this study, physiological hyperarousal was positively correlated with negative affect but not positive affect. This supports the tripartite model hypothesis, that physiological hyperarousal will distinguish anxiety from depression, which is related to positive affect. Another study by Joiner et al. (1999), analyzed the construct validity of physiological hyperarousal. Data were collected from samples of psychotherapy outpatients, air force cadets, and undergraduate students. Confirmatory factor analyses showed that psychological hyperarousal is a reliable, replicable, valid, and discriminable construct.Joiner, T., Steer, R., Beck, A., Schmidt, N., Rudd, M. D., & Catanzaro, S. (1999). Physiological hyperarousal: Construct validity of a central aspect of the tripartite model of depression and anxiety. Journal of Abnormal Psychology, 108(2), 290-298. doi:10.1037/0021-843X.108.2.290
Positive affect
Positive affect is a dimension that reflects one's level of pleasurable engagement with their environment.Clark, D., Steer, R., & Beck, A. (1994). Common and specific dimensions of self-reported anxiety and depression: Implications for the cognitive and tripartite models. Journal of Abnormal Psychology, 103(4), 645-654. doi:10.1037/0021-843X.103.4.645 High positive affect is made up of enthusiasm, energy level, mental alertness, interest, joy, social dominance, adventurousness, and activeness. In contrast, a low level of positive affect, or absence of, is called anhedonia.Joiner, T., Catanzaro, S., & Laurent, J. (1996). Tripartite structure of positive and negative affect, depression, and anxiety in child and adolescent psychiatric inpatients. Journal of Abnormal Psychology, 105(3), 401-409. doi:10.1037/0021-843X.105.3.401 Anhedonia is described as the loss of interest or the inability to experience pleasure when experiencing things that used to be pleasurable.Ho, N., & Sommers, M. (2013). Anhedonia: A concept analysis. Archives of Psychiatric Nursing, 27(3), 121-129. doi:10.1016/j.apnu.2013.02.001 Low levels of positive affect in the Tripartite Model characterize depression. Signs of low positive affect include fatigue, loneliness, sadness, and lethargy. Positive affect is important because it is a construct used in order to differentiate depression from anxiety.Gençöz, T. (2002). Discriminant validity of low positive affect: Is it specific to depression? Personality and Individual Differences, 32(6), 991-999. doi:10.1016/S0191-8869(01)00103-9
Many studies were completed to evaluate the role of positive affect in the tripartite model. A sample of university students were administered the Positive and Negative Affective Schedule (PANAS), the Beck Depression Inventory (BDI), and the Beck Anxiety Inventory (BAI). The results of this study were congruent with low Positive Affect predicting depression. A longitudinal study was completed with a sample of students in grade 6 and later grade 9. The students completed the Baltimore How I Feel (BHIF), a measure of anxious and depressive symptoms. This study confirmed the PA aspect of the tripartite model.Lambert, S., McCreary, B., Joiner, T., Schmidt, N., & Ialongo, N. (2004). Structure of anxiety and depression in urban youth: An examination of the tripartite model. Journal of Consulting and Clinical Psychology, 72(5), 904-908. doi:10.1037/0022-006X.72.5.904 A study with a sample of inpatient children/adolescents was consistent with the tripartite model as well. Findings from a study in 2006 of a community sample of youth supported the tripartite in youth and further supported that anxiety and depression do represent unique syndromes in youth based on differences found in positive affect.Cannon, M., & Weems, C. (2006). Do anxiety and depression cluster into distinct groups?: A test of tripartite model predictions in a community sample of youth. Depression and Anxiety, 23(8), 453-460. doi:10.1002/da.20215 Many studies looked at samples of youth but studies were also done with older adult samples. A study consisting of psychiatric outpatients, ages 55–87, confirmed that positive affect was significantly more related to depression than anxiety symptoms.Cook, J., Orvaschel, H., Simco, E., Hersen, M., & Joiner, T. (2004). A test of the tripartite model of depression and anxiety in older adult psychiatric outpatients. Psychology and Aging, 19(3), 444-451. doi:10.1037/0882-7974.19.3.444
Measures PANAS