American scientists have identified two types of schizophrenia by the structural peculiarities of the brain of patients. The first type is characterized by the usual diseases by reducing the volume of gray matter, and the second — increase of the basal nuclei and internal capsule. Yet it is not clear exactly how the two types are symptomatically, but in the future it may help in the diagnosis of schizophrenia, write the researchers in the journal Brain.
Initially, schizophrenia was divided into several types depending on the symptoms. For example, ICD and Diagnostic and statistical manual of mental disorders (DSM) has been identified with paranoid schizophrenia, in which hallucinations occur, disorganized, which is characterized by the manifestation of infantilism, catatonic and other. In the latest versions of both manuals all subtypes of schizophrenia were deleted: now in ICD-11, for example, schizophrenia is divided into episodic and continuous.
Despite the fact that the division of schizophrenia into subtypes according to the symptoms found to be invalid, the disease can still be categorized: for example, structural and functional features of the brain. Davatzikos Christos (Christos Davatzikos) at the University of Pennsylvania and his colleagues decided to focus on the anatomical differences in the brains of patients with schizophrenia. They used MRI scans of 307 patients with schizophrenia and 364 healthy people without mental disorders.
The data obtained, the researchers analyzed using an algorithm that automatically allocates subtypes of disease based on structural differences in a clinical sample, given the data obtained for healthy people: previously it has been used to study Alzheimer’s disease. The algorithm takes into account the volume of gray and white matter, and cerebrospinal fluid in the brain.
It turned out that patients can be divided into two types depending on structural differences of their brain. For the first type was characterized by a smaller volume of gray matter in many brain areas including the thalamus, nucleus accumbens and parts of the frontal lobes. The brain of the second type was distinguished by the large basal nuclei (clusters of gray matter) and internal capsule (accumulation of white matter).
Interestingly, two subtypes did not differ, sex and age of patients, duration of illness, psychiatric symptoms (both positive and negative), and also what the dosage of antipsychotic drugs the patient is taking. The volume of the gray matter of the brain significantly (p = 0.016) correlated with disease duration in patients with schizophrenia the first type: the smaller the size, the longer it proceeded the disease.
The smaller volume of gray matter in certain areas of the brain — are not uncommon for schizophrenia feature that, according to new data, also points to the fact that it may change with the course of the disease. Interestingly, however, the second type for which the decrease in the volume of gray matter could be detected. The authors note that it is not known what features of the disease are associated with such differences (this requires more research), but I hope that in the future the structural differences will be considered in the diagnosis.
Schizophrenia is one of the most mysterious mental illnesses: it is still unknown what causes it, and treatment is confined to relief of symptoms. To read more about what scientists have learned about schizophrenia over the last several decades, you can in our article “the thief of minds”.