From the Guidelines
Anhedonia is primarily caused by depressive disorders, including major depressive disorder (MDD) and dysthymia.
Causes of Anhedonia
- Depressive disorders, such as MDD and dysthymia, are characterized by symptoms including anhedonia, which is a loss of interest or pleasure in activities 1
- Major depressive disorder (MDD) is a clinical syndrome lasting at least 2 weeks, during which the patient experiences either depressed mood or anhedonia, plus at least 5 other symptoms, including significant weight loss or gain, insomnia or hypersomnia, and psychomotor agitation or retardation 1
- Dysthymia is a chronic depressive disorder characterized by depressed mood on most days for at least 2 years, and may also include symptoms of anhedonia 1
- Melancholia is a severe form of MDD, characterized by loss of interest or pleasure in all, or almost all, activities, as well as other physical symptoms such as early morning awakening and significant anorexia or weight loss 1
- Anhedonia can be assessed using various measures, including the Patient Health Questionnaire for Depression (PHQ-9), which includes items assessing little interest or pleasure in doing things 1
From the Research
Causes of Anhedonia
The causes of anhedonia are complex and multifaceted, involving various biological, psychological, and social factors. Some of the key causes and contributing factors include:
- Biological and brain-related impairment, such as alterations in striatal and prefrontal areas, with dopamine being the most involved neurotransmitter 2
- Deficits in neural reward and aversion functions, including impairments in anticipatory pleasure and integration of reward-related information 3
- Dysregulation of the frontostriatal circuit and mesocortical and mesolimbic circuit systems 3
- Inflammation, which may have a reciprocal deleterious effect on depression and anhedonia 2
- Genetic components, with polygenic risk scores being a possible tool for predicting an individual's risk for developing anhedonia 2
Social and Psychological Factors
Social and psychological factors also play a significant role in the development and maintenance of anhedonia, including:
- Interpersonal relationships and social aspects of anhedonia, which can contribute to anhedonic symptoms 4
- Trait-level dispositional tendencies, state-level cross-sectional assessments, and symptom-based recent changes from baseline, which can all be used to indicate anhedonia 4
- Deficits in positive affect, including deficits in the anticipation, consumption, and learning of reward 5
Neurophysiological Bases
The neurophysiological bases of anhedonia are not yet fully understood, but research suggests that:
- Alterations in striatal and prefrontal areas are involved in anhedonia 2
- The habenula, insula, amygdala, and anterior cingulate cortex may be involved in the dysfunction of aversion processing in depression and schizophrenia 3
- Blunted activation of the ventral striatum to reward-related cues and reduced functional connectivity involving the ventral striatum may be associated with anhedonia 6