Manic brain damage caused by antidepressants

Misdiagnosis: How the body makes the soul sick

In rare cases, specific antibodies are formed in the course of inflammation, which can activate or destroy receptors in the brain. These docking points for messenger substances are located in structures that are involved in the regulation of emotions, in mental images and hearing experiences. This can lead to a variety of psychiatric symptoms: mood swings, psychoses, hallucinations or what is known as catatonia, a state of motor tension in which the patient falls silent and switches back and forth between a rigid posture and overexcited behavior. One then speaks of limbic encephalitis, an inflammatory disease of the nervous system that can be rooted in cancer or an autoimmune disorder.

The origin of the psychological complaints is all the more difficult to identify as the tumor does not necessarily have to be located in the brain. A few years ago we found a tumor in one of the ovaries of Marie, a 22-year-old patient. This is often the case when it comes to a certain type of encephalitis called anti-NMDA encephalitis, named after the brain receptors that are attacked by antibodies. The patient actually came to the hospital because of a very severe depression. When the depression therapy didn't work, she was eventually referred to our department and we checked for abnormal antibodies in her brain water, the cerebrospinal fluid. This is how we found out that behind her symptoms was encephalitis. Surgery colleagues removed the tumor, and Marie was treated with immunosuppressive drugs, which often relieved symptoms and sometimes eliminated them completely. After a few weeks of therapy, her condition had improved enough that she could go home.

In the rare Niemann-Pick disease type C, an average of ten years elapse between the first psychiatric symptoms and the diagnosis of the organic cause

Other rare organopsychiatric disorders arise when certain molecules accumulate in the brain and disrupt its functions. This happens, among other things, with Niemann-Pick type C disease, which affects around one in 120,000 people. The psychiatric picture is similar to that of schizophrenia: thoughts and behaviors appear confused, the patient suffers from hallucinations and withdraws. On average, ten years elapse between the first psychiatric symptoms and the diagnosis of the organic cause. In the meantime, those affected are often given psychotropic drugs, but these remain largely ineffective.

So there are numerous organic causes that can cause psychiatric symptoms. Conversely, physical symptoms sometimes also have a psychiatric cause. In the case of neurological symptoms, one speaks of a conversion disorder; once referred to as hysteria. For example, the patient shows motor disorders such as paralysis or perception disorders such as sudden blindness or deafness. He can also have epileptic seizures, but without electroencephalography showing the usual abnormalities in the brain. Because of the variety of manifestations, the frequency of conversion disorders is difficult to estimate. According to some surveys, around four percent of patients who see a doctor for movement disorders are affected.

Although this pathology may seem fictitious, it is still very real - the symptoms are by no means merely imagined or made up. Recently, several studies using functional magnetic resonance imaging have shown that it is associated with some abnormalities in brain function. "Conversion disorders can be viewed as a kind of global brain disease," said Ismaël Conejero and his colleagues at the University of Montpellier, who in 2017 compiled the relevant findings in an article. These are functional disorders in neural networks that plan conscious movements and convey the feeling of initiating one's own actions. In addition, the researchers found unexpected connections between brain regions that are responsible for emotions and the networks involved in sensory perception and motor skills.

How do misdiagnoses occur?

In most cases, doctors make their diagnosis on the basis of an interview guide, which they do not use systematically, but rather according to their experiences and beliefs. This allows you to come to a decision more quickly, even without having to have complete information and without having checked a large number of possible diagnoses. But the risk of a misdiagnosis increases: for example, because they have a wrong idea of ​​the disease and fail to recognize when the symptoms deviate from the prototype. Or because they attach too much importance to certain symptoms: According to a US study, doctors consider delusions and hallucinations to be more important indicators of schizophrenia than disordered language or so-called negative symptoms such as apathy and social withdrawal - although the latter are more characteristic. The intuitive heuristics often lead to a psychiatric diagnosis with just a few clues. So many organic causes are overlooked. This is all the more problematic as there are no tests in psychiatry to confirm such a diagnosis. If a person is diagnosed as depressed, there is no biological marker that can be detected in a blood test or in a brain scan and that confirms or refutes the diagnosis. Many laboratories are looking for such markers.

Nonetheless, conversion disorder is often misdiagnosed because it is sometimes difficult to distinguish from a fake illness. But also because medical professionals tend to diagnose a conversion disorder if they cannot find an organic cause. Especially when it comes to women (who are certainly more often affected) or if there is a histrionic personality disorder, characterized by excessive emotions and a constant search for attention. However, recent studies show that the latter is not often associated with conversion disorders by accident.