Anhedonia is the inability to experience pleasure, the loss of interest or satisfaction in almost all activities. It is considered a lack of reactivity to normally pleasant stimuli. It is one of the clearest symptoms or indicators of depression, although it can be present in other disorders, such as some cases of dementia (Alzheimer’s), psychotic disorders, and schizoid personality disorder. The absence of dopamine in the brain causes anhedonia.
There are currently no effective treatments that specifically target anticipatory anhedonia, a major symptom of severe depression that is associated with poor outcomes. The present study investigated the efficacy of individualized repetitive transcranial magnetic stimulation (rTMS) targeting the nucleus accumbens (NAcc) network of the left dorsolateral prefrontal cortex (lDLPFC) on anticipatory anhedonia in depression.
This randomized, double-blind, sham-controlled clinical trial (NCT03991572) enrolled 56 depressed patients with symptoms of anhedonia. Each participant received 15 rTMS sessions once daily at 10 Hz and 100% motor threshold. The stimulation was located in the site of greatest connectivity IDLPFC-NAcc by functional magnetic resonance. The Hamilton Depression Rating Scale (HAMD) was used to measure depression severity, the Temporal Experience Pleasure Scale (TEPS) to measure anticipatory and consummatory anhedonia to specifically measure anticipatory/motivational anhedonia. Event-related potentials were recorded during the monetary incentive delay (MID) task to assess the electrophysiological correlates of reward anticipation and response.
Results: Patients in the Real group showed significant improvements in anticipatory anhedonia and general depressive symptoms after treatment compared to the Sham group. The Real group also demonstrated a more positive amplitude of cue-N2 and cue-P3 during MID reward tests after treatment. The change in cue-P3 after treatment was positively correlated with a better TEPS-anti score.
Xin Wang 1, Kongliang He 2, Tingting Chen 1, Bing Shi 1, Jie Yang 1, Wanyue Geng 3, Lei Zhang 1 4, Chunyan Zhu 1 4, Gongjun Ji 1 4, Yanghua Tian 4, Tongjian Bai 4, Yi Dong 2, Yuejia Luo 5, Kai Wang 1 4, Fengqiong Yu 1Affiliations expandPMID: 34157193
DOI: 10.1002/da.23188
