Research paperA comparison of neurometabolites between remitted bipolar disorder and depressed bipolar disorder: A proton magnetic resonance spectroscopy study

- We compared neurometabolites between remitted and depressed bipolar disorder (BD) patients by using proton magnetic resonance spectroscopy.
- We computed correlation coefficients between abnormal neurometabolites and clinical data in BD patients.
- We chose prefrontal whiter matter (PWM), thalamus and putamen as the volume of interest to be measured neurometabolites.
- The higher PWM N-acetylaspartate/Creatine ratios were found in remitted BD and controls than depressed BD patients.
- The correlations between abnormal N-acetylaspartate/Creatine ratios and clinical data in BD patients were also found.

BackgroundRecent many studies found the abnormal neurometabolites in the acute bipolar disorder (BD). However, limited studies were to detect neurometabolites in remitted BD, comparison between acute and remitted BD is conductive to understand the outcome of neurometabolites. This study sought to investigate the differences in neurometabolites between remitted and depressed BD patients using proton magnetic resonance spectroscopy (1H-MRS).MethodsThree subject groups were enrolled: 22 remitted BD patients, 22 depressed BD patients and 24 healthy controls. All subjects underwent 1H-MRS to measure N-acetylaspartate (NAA), Choline (Cho), myo-Inositol (mI) and Creatine (Cr) of several bilateral areas potentially involved in BD: prefrontal whiter matter (PWM), thalamus and putamen. The neurometabolite ratios were compared among three groups. The correlations between abnormal neurometabolite ratios and clinical data were computed.ResultsThe lower bilateral PWM NAA/Cr ratios were found in depressed BD patients than remitted BD patients and healthy controls, no differences were found between the remitted BD patients and controls. For depressed BD patients, left PWM NAA/Cr ratios showed negative correlation with age of onset, right PWM NAA/Cr ratios showed positive correlation with duration of illness.ConclusionsOur findings suggest the abnormal neurometabolites in the prefrontal lobe whiter may occur in the depressed BD. The remitted BD may resemble healthy subjects in terms of neurometabolites. In addition, abnormal neurometabolites in prefrontal lobe whiter may correlate with the age of onset and illness length.