New diagnostic tests for bipolar disorder and unilateral depression utilizing high resolution MRI, PET and SPECT scans of the brain are being used to distinguish one disorder from the other versus people with no mental illness. I must emphasize that these techniques are in the investigative stage and should not be used clinically to diagnose these diseases. This particular psychiatrists are now utilizing MRI to help families diagnose loved ones.
Inclusion of patients in neuroimaging studies use the traditional clinical symptoms of depression and mania. For depression these include sadness, guilt, pessimism, emptiness, worthlessness, agitation, hopelessness, early morning awakening, obsessing, not wanting to get bed, gain or loss of weight, suicidal ideation, loss of interest in hobbies, difficulty functioning, difficulty making decisions and lack of concentration. For mania the indicators are rapid speech, racing thoughts, tangential thinking, irritability, risky behavior, spending spaces, poor financial choices, drive to pursue multiple projects at the same time, feelings of superiority, hypersexuality and needing little sleep or combinations thereof.
In studies by the University of Iowa in 2013 a new high resolution MRI showed differences in blood flow to the white matter in the frontal lobe (the part of the brain involved with higher cognitive function and emotion) and cerebellum. The latter was an unexpected finding as this lobe at the back and inferior part of the brain is commonly felt to be responsible for balance as in allowing people to recognize standing, sitting, leaving, etc. A later study by the same group showed that the changes seen in bipolar patients resolved on lithium.
Studies by the University of Michigan to evaluate metabolic function of brain cells have been evaluated by PET and SPECT scans. By injecting a radioactive labeled glucose intravenously differences can be seen in bipolar patients versus patients without any mental illness.
An ongoing trial sponsored by Stony Brook University in collaboration with the NIMH and The Dana Foundation is utilizing PET and functional MRI imaging. This study of bipolar disease, major depression and the effect of treatment is in progress and still recruiting volunteers. The start date was in August of 2012 and the completion date is May of 2016. The purpose of the study is to quantify serotonin binder protein 5-HTT in brain cells of bipolar patients during bipolar depression and after treatment with Lithiuim or Lamictal. The same methods will be used to see if a distinction can be made between bipolar depression and unipolar or major depression alone.
I have been treated for bipolar disease for almost forty-five years and I have never needed or been offered brain imaging. The diagnosis and treatment has been by clinical indicators and is still the gold standard.