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Symptoms of Schizophrenia & Criteria for Diagnosis

Learn about the symptoms of schizophrenia and the criteria for diagnosis from psychiatrist Jeanie Tse in this Howcast video.


Hi. I'm Jeanie Tse, and I'm here to tell you about the symptoms of schizophrenia and the criteria for diagnosis. There are five main symptom areas in schizophrenia that we look at.

One is delusions, which are fixed false beliefs that are not shared by other people in the culture. So, those can include paranoid delusions that other people are trying to harm you or that there's a plot against you. Or, grandiose delusions, where you feel that you are more important than perhaps you are, that you have a mission to accomplish or things like that.

There are many kinds of delusions and there are different kinds of hallucinations, which is the second symptom area, as well. So, hallucinations are problems of perception where you might think that someone is speaking to you, when no one is in fact speaking to you. Or, you might see things that other people don't see.

So, those are hallucinations. There's disorganized thought and disorganized behavior as well, which affect how you communicate with others, how you are understood, and as well your ability to take care of yourself and organize your activities.

The fifth symptom area of schizophrenia is negative symptoms, and so people who have negative symptoms may have a very flat affect. So, no smiles, no crying, just looking flat. They may not have a lot of motivation to do things. Their thinking may be slowed or even largely absent, and so they don't enjoy things as much as they used to.

So, those are the main five symptom areas of schizophrenia. But to have the diagnosis of schizophrenia, these things have to be present for at least one month and there has to be at least six months where there's a decline in the usual areas of functioning. So, somebody may have been able to work and take care of their family and over six months that starts to deteriorate.

So, those and sort or excluding that substance use or that medical condition could be causing these symptoms are what is needed to make a diagnosis. We make this diagnosis by doing a clinical interview, so interviewing the person and also finding out from people who know them what has been going on so that we can corroborate that history.

There are no brain tests or blood tests that reliably tell us whether someone has schizophrenia. So, it's really that human interaction, trying to find out what that person is experiencing that tells us whether they have schizophrenia or not.

Of note, the DSM-5, the Diagnostic and Statistical Manual that we use in psychiatry to make diagnosis, has just been revised, and so it's just come out in May of this year. There are some changes to the diagnosis.

Largely, the criteria I've just talked about haven't changed. But, there used to be a lot of subtypes of schizophrenia, including paranoid type, disorganized type, and those have been eliminated because they didn't seem to hold up in the research as being separate. In fact, schizophrenia is probably a heterogeneous condition. It's probably a mix of many different kinds of disorders. But the subtypes that we were using before don't seem to be accurate.

We should also note that schizoaffective disorder is a very closely related condition to schizophrenia. So, it's basically schizophrenia with the addition of mood episodes on top of it, including depressive episodes where, obviously, you feel sad or depressed and may have troubles with sleep, with appetite, with enjoying things, and even suicidal thinking.

Or, manic episodes on top of schizophrenia, which include an elevated mood, increased energy, lack of sleep, inflated self-esteem and increased activity, and sometimes reckless behaviors. So, those symptoms, if they are present in the presence of schizophrenia, qualify you for schizoaffective disorder.

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