Schizophrenia - causes, symptoms, diagnosis, treatment & pathology

Sharing buttons:

Schizo means split, and phrenia, in this case refers to the mind. Even though schizophrenia

can be interpreted to mean “splitting of the mind”, it does not refer to a split

personality, like some media sources might portray, but rather schizophrenia describes

a scattered or fragmented pattern of thinking. Schizophrenia’s actually a syndrome, meaning

there’re all sorts of symptoms that might be associated with it and different patients

might experience different symptoms, although the symptoms can be broadly categorized into

three major areas: positive symptoms, negative symptoms, and cognitive symptoms.

Alright taking a step back, most human symptoms from any illness are extreme versions of a

normal physiologic process (for example everyone has a heartbeat and tachycardia is a fast

heartbeat, everyone has a normal body temperature, but during a fever that temperature is higher).

In schizophrenia, patients have positive symptoms which aren’t positive in the sense that

they’re helpful, but positive in the sense that they’re some new feature that doesn’t

have some “normal” or physiologic counterpart. These are the psychotic symptoms, so delusions,

hallucinations, disorganized speech, and disorganized or catatonic behavior; none of which occur


Delusions are false beliefs that the patient might feel very strongly about, so much so

that they won’t change their mind, even if you give them evidence against it. There

are all sorts of different delusions, like, for example, a delusion of control, where

somebody thinks that some outside force or person or thing is controlling their actions.

They could also be delusions of reference, where someone might think that insignificant

remarks are directed at them, like a newscaster is speaking directly to them through the TV.

Hallucinations are a second type of positive symptom, and can be any kind of sensation

that’s not actually there, including visual but also including auditory sensations, like

hearing voices or commands. A third type is disorganized speech An example being something

like a “word salad”, which seems like just a random jumbling of words or phrases,

like “pencil dog hat coffee blue”. Disorganized behavior on the other hand could be like if

they exhibit bizarre or silly behavior that’s out of context and doesn’t seem to have

much of a purpose, like for example wearing multiple layers of jackets on a hot summer

day. Also sometimes the behavior is described as “catatonic”, which has to do with their

movements, posture, and responsiveness. So like they might be super resistant to moving,

or be in an unresponsive stupor.

Negative symptoms, are like when there’s this reduction or removal of normal processes,

and this is like a decrease in emotions they can express, or a loss of interest in things

they once found interesting. One type of a negative symptom is called flat affect, where

they don’t respond with an emotion or reaction that would seem appropriate, like if they

saw something very unexpected like a small monkey playing in their living room, they

might simply sit and watch idly as if nothing was happening. Another type is alogia, or

poverty of speech, which is a lack of content in speech, so like if somebody asked them

“do you have any children?”, they might respond with “yes”, instead of “yes,

one boy and two girls”. A third type of negative symptom is avolition, which is this

decrease in motivation to complete certain goals, so someone might stay at home for long

periods of time, without trying to reach out to friends or find work.

Cognitive symptoms include things like not being able to remember things, learn new things,

or understand others easily. These symptoms are more subtle though, and more difficult

to notice and might only be detected if they have really specific tests performed. An example

might be somebody not being able to keep track of several things at once, like a phone number

and an address.

People with schizophrenia seem to cycle through three phases, typically in order. During the

prodromal phase, patients might become withdrawn and spend most of their time alone, and often

this seems similar to other mental disorders like depression or anxiety disorders. During

the active phase, patients experience more severe symptoms like delusions, hallucinations,

disorganized speech, disorganized behavior, or catatonic behavior. Following an active

phase, patients often enter into a residual phase, where they might exhibit cognitive

symptoms like not being able to concentrate or becoming withdrawn again, as with the prodromal


For an official diagnosis of schizophrenia, patients need to be diagnosed with two of

the following symptoms—Delusions, hallucinations, disorganized speech, disorganized behavior

or catatonic behavior, or negative symptoms, and at least one of them has to be either

delusions, hallucinations, or disorganized speech, So basically they couldn’t have

just disorganized behavior and negative symptoms. Even though some patients have cognitive symptoms

as well, they aren’t specifically needed for a diagnosis. Also though, for a diagnosis,

signs of these disturbances must be ongoing for at least 6 months, meaning they’re likely

in one phase or another for 6 months, but there must be at least one month of active-phase

symptoms. And finally, those symptoms can’t be attributable to another condition, like

substance abuse.

Now that we’ve diagnosed it...why does it even happen in the first place? What causes

schizophrenia? Well we don’t really know, since it seems like the signs and symptoms

of schizophrenia are pretty unique to humans, or at least they’re hard to imagine or notice

in animal models like mice or rats. One clue is that the majority of antipsychotic medications

that improve schizophrenia symptoms block the dopamine receptor D2, which reduces dopamine

levels in neurons. This suggests that maybe schizophrenia has something to do with increased

levels of dopamine. These medications, though, are neither universally nor completely effective,

and don’t work for everyone with schizophrenia, which adds to the confusion and means there’s

probably more to it than just the D2 receptors. Interestingly, one of the most effective antipsychotic

drugs, clozapine, is a weak D2 antagonist, suggesting that other neurotransmitter systems

like norepinephrine, serotonin, and GABA are involved. Twin studies have shown support

for a genetic basis as well, even though there haven’t been any specific genes conclusively

linked to schizophrenia yet. Also, environmental factors, like early or prenatal exposure to

infection, and certain autoimmune disorders like celiac disease have been linked with

schizophrenia. Finally, another important set of clues involves the epidemiology, schizophrenia

seems to happen slightly more in men than women, with onset in the mid-twenties for

men but late-twenties for women; and the clinical signs of schizophrenia are often less severe.

Some studies suggest this difference might be due to an estrogen regulation of dopamine

systems. There doesn’t, however, seem to be any differences among race.

Now treating schizophrenia can be really tricky, and antipsychotic medications are often used,

but it’s super important to combine the efforts of several clinicians and health professionals,

including professionals in therapy or counseling, medicine, and psychopharmacology. Antipsychotics

can be very effective at reducing symptoms, but they often come a lot of additional considerations

to keep in mind, like cost and the potential for unwanted side effects like tolerance,

dependence, and withdrawal.