Cognitive Behavioral Therapy as Possible Treatment for Anxiety-Depression Comorbidity

According to the National Institute of Mental Health (NIMH), anxiety is the most common mental

illness in the United States, affecting 40 million adults, nearly 18% of the U.S. population. Additionally, the NIMH reported that 10.2 million adults are affected by symptoms of major depression. That being said, it is highly critical that work be done to identify the nature of these diseases and how best to help those suffering.

Dr. Stewart Shankman recently came to Loyola University Chicago to talk to neuroscience students about anxiety and depression. Dr. Shankman spoke about a recent study, A Psychological Investigation of Threat and Reward Sensitivity in Individuals With Panic Disorder and/or Major Depressive Disorder, in which Gorka et al. (2013) broke down the relationship between anxiety disorders, depressive disorders, and anxiety-depression comorbidity. It is generally thought that the main component of anxiety is a heightened sensitivity to predicted/unpredicted threats, and the major component of depression is a reduced sensitivity to reward. Threat anticipation associated with anxiety was measured via the NPU-threat paradigm in which participants were either not exposed to an aversive stimulus, exposed to a predicted adverse stimulus, or exposed to an unpredicted adverse stimulus. The operational definition of sensitivity to threat was startle response. The sensitivity to reward associated with depression was measured via a virtual slot task in which participants pressed a button that had the potential to result in the winning of money. The operational definition of sensitivity to reward was an asymmetrical frontal EEG reading. Four different groups of participants complete both of these tasks: panic disorder (PD) only, major depressive disorder (MDD) only, comorbid panic disorder and major depressive disorder, and control participants. Results showed that PD, regardless of MDD, was uniquely associated with a heightened startle response to both predicted and unpredicted adverse stimuli. Additionally, MDD, regardless of PD, was uniquely associated with frontal EEG asymmetry while the participants anticipated the possible money reward. Interestingly, the results did not suggest that anxiety-depression comorbidity is simply an amplification of these disorder specific characteristics. The paper concluded that anxiety-depression comorbidity may be better characterized as higher levels of general distress and negative temperament associated with anxiety and depression respectively.
These findings suggest that treatment of anxiety-depression comorbidity should not simply consist of anxiety treatment and depression treatment. In a recent study, Randomized Controlled Trial of Group Cognitive Behavioral Therapy for Comorbid Anxiety and Depression in Older Adults, Wuthrich and Rapee (2013) found group CBT as an effective means to treat anxiety-depression comorbidity. The group CBT utilized in the study consisted of various interventions such as psychoeducation, cognitive restructuring, and graded exposure. The graded exposure consisted of components typically used to treat anxiety and components typically used during activity scheduling to treat depression. This success of blending anxiety and depression interventions into a unique treatment for anxiety-depression comorbidity confirms Gorka et al. (2013)'s finding that comorbidity is not simply anxiety and depression that co-occur as two separate disorders. These studies draw important attention to the nature of anxiety and depression and how the millions of people suffering from these disorders can be helped.

Resources:

Shankman, S. A., Nelson, B. D., Sarapas, C., Robison-Andrew, E. J., Campbell, M. L., Altman, S. E., ... & Gorka, S. M. (2013). A psychophysiological investigation of threat and reward sensitivity in individuals with panic disorder and/or major depressive disorder. Journal of abnormal psychology, 122(2), 322.

Wuthrich, V. M., & Rapee, R. M. (2013). Randomised controlled trial of group cognitive behavioural therapy for comorbid anxiety and depression in older adults. Behaviour research and therapy, 51(12), 779-786.

http://www.nimh.nih.gov/health/statistics/prevalence/any-anxiety-disorder-among-adults.shtml

Picture: http://www.thesmarterbrain.net/break-the-link-between-depression-and-anxiety/