Currently, doctors do not use brain images to diagnose bipolar disorder. However, as research advances, more evidence may help doctors use MRI scans or other imaging technology to accurately diagnose bipolar disorder.
A study completed in 2020 used a combination of structural and functional MRI imaging techniques to effectively identify patients with bipolar at an accuracy of 87.5%. A doctor might recommend a brain scan for someone with bipolar symptoms in order to identify and rule out other conditions.
Moderate quality evidence suggests increases in the cerebellum, bilateral middle frontal gyrus, right middle temporal gyrus, right inferior temporal gyrus, the right middle occipital gyrus, left putamen, and left posterior cingulate cortex of people with bipolar disorder.
SVM has also been used to accurately identify different mental disorders in functional MRI studies [41,42,43]. In terms of BPD, Redlich and colleagues previously used an SVM algorithm based on the whole-brain gray matter to distinguish between BPD and unipolar depression with an accuracy of almost 76% [44].
Brain scans alone cannot be used to diagnose a mental disorder, such as autism, anxiety, depression, schizophrenia, or bipolar disorder. In some cases, a brain scan might be used to rule out other medical illnesses, such as a tumor, that could cause symptoms similar to a mental disorder, such as depression.
MRI can be used to detect brain tumors, traumatic brain injury, developmental anomalies, multiple sclerosis, stroke, dementia, infection, and the causes of headache. Figure 1.
To diagnose bipolar disorder, a doctor performs a physical exam, asks about your symptoms, and recommends blood testing to determine if another condition, such as hypothyroidism, is causing your symptoms. If the doctor does not find an underlying cause of your symptoms, he or she performs a psychological evaluation.
The most common misdiagnosis of bipolar disorder is major depressive disorder (MDD). The symptoms of major depression last for at least two weeks and can include: persistent feelings of sadness or low mood.
Bipolar disorder is often diagnosed during late adolescence (teen years) or early adulthood. Sometimes, bipolar symptoms can appear in children. Although the symptoms may vary over time, bipolar disorder usually requires lifelong treatment.
No two people with bipolar disorder share the same thoughts or experiences, but there are some common thought patterns among most folks who have it. This includes cyclical thinking, manic and/or depressive episodes, suicidal ideation, and psychosis.
Chemical imbalance in the brain
There is some evidence that bipolar disorder may be associated with chemical imbalances in the brain. The chemicals responsible for controlling the brain's functions are called neurotransmitters, and include noradrenaline, serotonin and dopamine.
It's common in children and adolescents, but it usually doesn't get diagnosed until adulthood—it can take up to ten years from the time a person experiences symptoms to the time they actually get diagnosed! So no, not everyone who has bipolar disorder knows they have it.
Only a mental health professional like a psychiatrist can give you a bipolar disorder diagnosis – not your GP. However, if you're experiencing bipolar moods and symptoms, discussing it with your GP can be a good first step. They can refer you to a psychiatrist, who will be able to assess you.
Bipolar disorder
Bipolar is one of the most frequently misdiagnosed mental health issues. Somewhere between 1.4 and 6.4 percent of people worldwide are affected by bipolar disorder. However, it's hard to say which number is more accurate due to the frequency of wrongful diagnosis.
Bipolar disorder type II is especially difficult to diagnose accurately because of the difficulty in differentiation of this disorder from recurrent unipolar depression (recurrent depressive episodes) in depressed patients.
Many of the symptoms of a manic bipolar episode and ADHD may be similar, such as distractibility, restlessness, or impulsivity. So ADHD may go undiagnosed in a person with bipolar disorder, if a doctor mistakes ADHD symptoms for a manic episode.
Bipolar disorder can only be diagnosed after a full episode of mania or hypomania has occurred. Therefore, people whose bipolar disorder commences with an episode of depression and/or hypomanic symptoms that do not meet diagnostic threshold may be diagnosed initially with a depressive disorder.
If your GP thinks you may have bipolar disorder, they'll usually refer you to a psychiatrist, a doctor who specialises in mental health problems. If your illness puts you at risk of harming yourself, your GP will arrange an appointment immediately.
Dementia
While no diagnostic test alone can diagnose dementia, MRI scans are used for Alzheimer's or other dementias to track the change of the disease over time.
MRIs are more versatile, and doctors use them for examining many medical conditions. For example, x-rays are used more for examining broken bones, but they can also help detect diseased tissue. MRIs are better for evaluating soft tissues such as tendon and ligament injuries, brain tumors or spinal cord injuries.
White matter lesions (WMLs) are areas of abnormal myelination in the brain. These lesions are best visualized as hyperintensities on T2 weighted and FLAIR (Fluid-attenuated inversion recovery) sequences of magnetic resonance imaging. They are considered a marker of small vessel disease.
If imaging of the brain is needed in a patient with first-episode psychosis, an MRI should be preferred over a CT scan. This is because an MRI has much greater sensitivity for picking up brain pathology and because an MRI avoids exposure to ionizing radiation (Forbes and Stuckey, 2020).