Schizophrenia might not be the one-size-fits-all diagnosis it was long assumed to be. 

For the first time, researchers have pinpointed two different types of schizophrenia based on the shape and structure of the brain. Not only could this provide some insights into the nature of the psychiatric disorder, it could also explain why people's responses to treatment and medication can vary so massively.

Reported in the journal Brain today, scientists from the University of Pennsylvania School of Medicine scanned the brains of over 300 people with schizophrenia, as well as over 360 healthy controls for the sake of comparison. 

By looking at volumes of the brain’s gray matter, the researchers were able to identify “two distinct neuroanatomical subtypes of schizophrenia.” Known as Subtype 1, around 60 percent of the patients were found to have lower volumes of gray matter throughout the brain when compared to healthy people. The remaining 40 percent had volumes of gray matter similar to the brains of people without schizophrenia, which the researchers dubbed Subtype 2.

“Numerous other studies have shown that people with schizophrenia have significantly smaller volumes of brain tissue than healthy controls. However, for at least a third of patients we looked at, this was not the case at all – their brains were almost completely normal," principal investigator Christos Davatzikos, PhD, from the Perelman School of Medicine at the University of Pennsylvania, said in a statement.

"In the future, we're not going to be saying, 'This patient has schizophrenia,' We're going to be saying, 'This patient has this subtype' or 'this abnormal pattern,' rather than having a wide umbrella under which everyone is categorized."

Scientists have suggested there could be multiple types of schizophrenia for a couple of years, but this is some of the sturdiest evidence yet. 

Schizophrenia is a mental illness characterized by relapsing episodes of psychosis. Symptoms can vary widely between patients, but the condition typically presents with hallucinations, hearing voices, paranoid thoughts, disorganized thinking, and delusions.

Although it can be effectively treated with medications, it can often prove difficult to find the right treatment. Some people respond well to certain medications, while others will not respond well at all, often with little explanation. Perhaps, the researchers suggest, the different subtypes of schizophrenia could be responsible for these different responses. If that's the case, the researchers hope their work could be used to guide us towards more effective, personalized treatments for the condition. 

"The treatments for schizophrenia work really well in a minority of people, pretty well in most people, and hardly at all in a minority of people. We mostly can't predict that outcome, so it becomes a matter of trial and error," study co-senior author Daniel Wolf, MD, PhD, an associate professor of psychiatry at Penn. "Now that we are starting to understand the biology behind this disorder, then we will hopefully one day have more informed, personalized approaches to treatment."