Anhedonia

Did You Know?

• Anhedonia was found to be a risk factor for suicidal behaviors in a 2023 meta-analysis.
• Sexual anhedonia in males is also known as ejaculatory anhedonia.
• The concept was formally coined by Théodule-Armand Ribot and later used by Paul Eugen Bleuler and Emil Kraepelin.

Causes

Neurobiological substrates implicated in anhedonia include the prefrontal cortex, orbitofrontal cortex, striatum, amygdala, anterior cingulate cortex, hypothalamus, and ventral tegmental area. Deficits in consummatory reward are associated with abnormalities in the ventral striatum and medial prefrontal cortex, while anticipatory reward deficits relate to hippocampal, dorsal ACC, and prefrontal regions. The neurotransmitter dopamine is central to the brain's reward system, and anhedonia may result from its breakdown. Akinetic mutism, caused by a lesion to the anterior cingulate cortex, is closely related to negative symptoms.

Occurrence

Anhedonia occurs in roughly 70% of people with major depressive disorder and is a core symptom, allowing diagnosis even without depressed mood. In schizophrenia, it is a negative symptom; people with schizophrenia retrospectively report fewer positive emotions but show intact consummatory pleasure when presented with rewarding stimuli. Neuroimaging in schizophrenia reveals reduced responsiveness during reward anticipation, and deficits in reinforcement learning appear when tasks require explicit learning. Anhedonia is common in dependence on alcohol, opioids, cannabinoids, and nicotine, and is a significant predictor of relapse.

Treatment

Traditional pharmacotherapies, including dopaminergic therapies, have been difficult to use for anhedonia in major depressive disorder. A 2024 network meta-analysis found that pro-dopaminergic strategies like bupropion produced small improvements, while non-dopaminergic antidepressants showed larger effects. Ketamine may exert anti-anhedonic effects in depressive episodes, with neuroimaging evidence linking changes in functional connectivity to symptom improvement. Minocycline reduced anhedonia-related outcomes in a 2019 meta-analysis. Amantadine has shown potential in preclinical studies by reversing reductions in sucrose preference and preserving dopamine levels.