How is bipolar diagnosed? Bipolar disease is a clinical diagnosis made on the basis of a series of diagnostic criteria, psychiatric evaluation, self-questionnaires, mood charts and individual retrospective evaluation at the onset of a first major depression episode. In the last three years the use of various brain imaging methods are now being added to distinguish bipolar disease and unipolar depression from healthy controls. These include high resolution MRI, functional MRI, PET scans and a variation of PET known SPECT scans to assess brain chemistry in bipolar disease, unipolar depression and bipolar depression.
The traditional clinical signs and symptoms the major depression side of bipolar disease are: feelings of sadness, guilt, pessimism, emptiness, worthlessness, agitation, hopelessness, early morning awakening, obsessing, not wanting to get of bed, gain or loss of weight, suicidal ideation, loss of interest in hobbies, difficulty functioning, difficulty making decisions, fatigue and lack of concentration. Any five of these that last more than two weeks defines major depression.
How is Bipolar Diagnosed with Manic Behavior?
As far as manic behavior indicators are: rapid speech, racing thoughts, aggressive behavior, irritability, risky behavior, spending sprees, poor financial choices, drive to pursue multiple projects at the same time, needing to be the life of the party and hyper-sexual behavior.
Two variants of bipolar disease are bipolar I and bipolar II base on the severity of the manic component.
How is Bipolar Diagnosed with Brain Imaging?
Brain imaging may help as the diagnosis of bipolar disease may take years and may erroneously be diagnosed as ADD, ADHD, major depression alone or schizophrenia.
In two studies using MRI scans in 2013 one out of Mt. Sinai and the other out of Kings College London showed an accuracy of 72 percent and 73 percent respectively. In the first study 26 scans of bipolar patients and normal controls had a 73 percent accuracy compared to a clinical diagnosis. In the second study of 14 bipolar versus 14 control subjects the accuracy was 72 percent.
In another study out of the University of Iowa using a newer high resolution MRI showed differences in the white matter of the cerebrum (the majority of brain matter) and the cerebellum (towards the back and bottom). The study involved 15 patients with bipolar disease on Lithium and 25 controls of same sex and age. The bipolar subjects showed high signals in the cerebral white matter (the part involved with motor function and higher intellectual functions) and in the cerebellum which is largely involved with balance. The speculation is the abnormal brain cells have a different acidity or glucose concentration.
Prior studies with older MRI technology had concentrated on the frontal lobe where emotions are derived.
Provocative studies out of the University of Michigan in 2014 using PET scans have shown that people with bipolar disease I on treatment have a different density of cells that produce the three main neurotransmitters serotonin, norepinephrine and dopamine. Called monoamines they are involved in mood, stress, pleasure and cognitive function. By zeroing on parts of the brain where these cells are located they studied the PET scans of 16 treated patients with bipolar disease and 16 healthy controls… They used a weakly radioactive sugar tracer that when injected intravenously binds with monoamine producing cells. Bipolar patients had an average 31 percent 28 percent more binding sites in two specific parts of the brain (thalamus and ventral brain stem) respectively compared to control patients.
A clinical trial by the National Institutes of Health and Stony brook University is now enrolling patients for studies involving PET and MRI imaging of patients with bipolar and unipolar depression comparing metabolic activity of the neurotransmitter serotonin in Lithium and Lamictal treated patients.
There remains controversy about the usefulness of brain imaging as a diagnostic tool in bipolar disease and unipolar depression. These studies are, therefore, limited to clinical studies and should not be used in practice by psychiatrists. The clinical indicators of bipolar disease and major depression are still the gold standard.