Doctors who specialize in mental health used to divide schizophrenia into five subtypes. The diagnosis depended on one main kind of symptom when the doctor first examined you.
But the severity of symptoms can change or overlap. Your subtype might not stay the same, or it could be difficult for a doctor to classify. And that caused problems treating people, so the system using subtypes has fallen out of favor.
There is no test that can make a schizophrenia diagnosis. People with schizophrenia usually come to the attention of a mental health professional after others see them acting strangely.
Doctors make a diagnosis through interviews with the patient, as well as with friends and family members.
Psychiatrists have the most experience with diagnosing schizophrenia. A psychiatrist or other licensed mental health professional should be involved in making a schizophrenia diagnosis whenever possible.
Instead, in 2013, the standard book that mental health experts use, called The Diagnostic and Statistical Manual of Mental Disorders, changed how schizophrenia is classified.
This illness is now considered a spectrum disorder, like autism is. It's a group of related mental disorders that share some symptoms. They're like variations on a theme in music. They affect your sense of what's real. They change how you think, feel, and act.
The main disorder is schizophrenia. It includes all the previous subtypes: catatonic, disorganized, paranoid, residual, and undifferentiated.
It's a psychosis -- what seems real to you isn't. It can look like:
Delusions: Mistaken but firmly held beliefs that are easy to prove wrong, like thinking you have superpowers, are another famous person, or people are out to get you
Disorganized speech: Using words and sentences that don't make sense to others
Strange behavior: Acting in an odd or repetitive way, like walking in circles or writing all the time, or sitting perfectly still and quiet for hours on end
Withdrawn and lifeless: Showing no feelings or motivation, or lacking interest in normal daily activities
To be diagnosed with schizophrenia, you have to have at least two of these symptoms for at least 6 months. One of them must be hallucinations, delusions, or disorganized speech. A single voice that offers ongoing comments about your thoughts and actions, or voices that talk to each other, is enough.
There could have been times when you didn't have any symptoms, but the first one would have started at least 6 months ago. And you must have had them for at least a month continuously.
You may have different symptoms at different times, and they may get worse or better -- and it's still schizophrenia.
Doctors may still categorize your schizophrenia according to its predominant symptom, to make a diagnosis clearer. But rather than saying you have "paranoid schizophrenia," they would say you have "schizophrenia with paranoia."