SAN FRANCISCO – Anhedonia is the symptom dimension that cuts most strongly across the diagnostic boundaries of anxiety and depression and contributes most to the characteristically poor quality of life in both, Emily C. Livermore reported at the annual conference of the Anxiety and Depression Association of America.
“Our results suggest that anhedonia may have a disproportionate impact on disability from depression and anxiety and may be an important target for tailoring treatment and assessing treatment outcomes,” declared Ms. Livermore, a doctoral student in clinical psychology at Stanford (Calif.) University.
She presented a study of 121 adults with anxiety or depressive symptoms. The study was conducted under the auspices of the National Institute of Mental Health’s Research Domain Criteria (RDoC) initiative. The RDoC program is intended to promote a new way of studying mental disorders based on dimensional psychological constructs independent of traditional psychiatric diagnoses, which in some circles are now dismissed as “silos.” In keeping with the RDoC goals, Ms. Livermore and her coinvestigators examined diagnosis-independent dimensions of symptoms and how they affected quality of life.
The investigators obtained a comprehensive picture of the participants’ symptoms and quality of life by having them complete the Penn State Worry Questionnaire, the Mood and Anxiety Symptoms Questionnaire, the Depression Anxiety Stress Scale, and the World Health Organization Quality of Life – Brief Version.
The investigators then mapped the symptoms and their interconnections in order to identify what they called transdiagnostic symptom factor dimensions. They found four of them, which they termed anhedonia, worry, tension, and anxious arousal, a dimension encompassing physical symptoms including shortness of breath and heart palpitations.
Next, using regression analyses, they examined the relationship between levels of those four symptom factor dimensions and the four quality of life domains captured in the WHO instrument, namely, physical, psychologic, environmental, and social quality of life. Study participants averaged unhealthily low quality of life scores on two of these domains – the psychological and social – as defined by scores more than one standard deviation below normative.
Of the four symptom dimensions, anhedonia stood out as having moderate to-strong negative associations with all four quality of life domains. The other three symptom dimensions showed no or only weak associations with the four quality of life domains, with the exception of anxious arousal, which displayed a moderate relationship with physical quality of life.
Ms. Livermore reported having no financial conflicts regarding the study, which was funded by the National Institute of Mental Health.