Striatal dopamine transporter availability in unmedicated bipolar disorder

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Dopamine transmission is crucial for brain function and implicated in bipolar disorder (BPD).
• The dopamine transporter (DAT) regulates dopamine levels and serves as a marker for presynaptic dopamine function.
• Limited neuroimaging studies exist on the dopamine system in BPD.

Purpose of the Study:

• To investigate differences in dopamine transporter (DAT) availability between individuals with BPD and healthy controls.
• To utilize positron emission tomography (PET) imaging to assess DAT availability in the brain.

Main Methods:

• PET imaging with [(11)C]CFT radiotracer was performed on 11 unmedicated BPD patients and 13 healthy controls.
• Structural MRI scans were acquired for all participants.
• Striatal binding potential (BP(ND)) was calculated using the multilinear reference tissue model.

Main Results:

• Significantly lower DAT availability was observed in the bilateral dorsal caudate of unmedicated BPD subjects compared to healthy controls.
• This indicates reduced presynaptic dopamine transporter function in individuals with BPD.

Conclusions:

• The findings support the hypothesis of dopaminergic system abnormalities in BPD.
• Reduced DAT availability may be linked to the neuropathology of bipolar disorder.
• Further research is needed to explore the relationship between DAT availability and disease phases in BPD.