What is Psychosis?

Having a mental problem, also called a psychiatric condition, can be an extremely difficult experience. Conditions such as depression, phobias, or panic attacks can place a huge emotional load on people. Many of these conditions develop, or start to develop, during adolescence (see Figure 1A). Among psychiatric conditions, psychosis is often considered the most devastating. Some people prefer the term schizophrenia, while others prefer psychosis—we will use the latter [1]. It is estimated that, on average, about three out of 1,000 people experience this condition at any given moment.

When psychiatrists describe psychosis, they usually refer to three types of symptoms—cognitive problems, negative symptoms, and positive symptoms (see Figure 1B). Cognitive problems include symptoms such as problems with thinking. Reduced problem-solving abilities are one example of a problem with thinking. The negative domain defines traits or symptoms that are reduced among people who suffer from psychosis relative to people from the general population. Examples of the negative domain symptoms are: reduced motivation, incomprehensible (not understandable) speech, and social withdrawal. For example, a person experiencing negative symptoms might lose interest in meeting friends and prefer to spend all their time alone. The positive domain defines traits or symptoms that are enhanced among people who suffer from psychosis relative to people from the general population. Examples of the positive domain symptoms include symptoms such as hallucinations and delusions. A person who experiences delusions might falsely think that everybody is talking about them behind their back. Similarly, a person who experiences hallucinations might see things that do not exist. Hearing voices is the most common hallucination among people who suffer from psychosis.

Causes of Psychosis

Multiple factors contribute to the development of psychosis. What scientists call environmental factors can play an important role. Children who experience trauma have a higher chance of developing psychosis when they grow up. For example, paternal neglect or sexual abuse are forms of trauma that toddlers and kids might experience. Similarly, people who smoke marijuana (cannabis) have an increased risk of developing psychosis.

But this is not the whole story. Genes also contribute to an increased risk of developing psychosis. What does this mean? In each person’s cells, the genetic material holds the code for their development. The genetic material is built out of a long chain of subunits. In some places, the sequence of these subunits differs between different people. Common sequence differences include (i) differences in a single letter [see Figure 1C (i)]; (ii) insertion of several letters to the sequence of a minority group of the population [see Figure 1C (ii)]; and (iii) deletion of several letters of the sequence of a minority group of the population [see Figure 1C (iii)]. Each one of these differences on its own might contribute to a tiny risk of developing psychosis. Together, many genetic differences can lead to a substantially increased risk.

Biomarkers—Biological Signs of Psychosis

Genetic differences result in small differences between the brains of people who develop psychosis and those of healthy people. Scientists call these brain differences biomarkers. That is, “bio” (which refers to life or living things) and “markers”, which indicate something. So, biomarkers are markers or signs of a medical or non-medical condition that scientists aim to identify. For example, a biomarker can be differences in the concentration of molecules called neurotransmitters, which brain cells use for communication. Also, changes in the amount of gray matter in some brain areas, which is made from the cell bodies of brain cells called neurons, might be a biomarker for psychosis (see Figure 1D). Similarly, the integrity of the long axon (see Figure 1D) in some parts of the brain can be a biomarker for psychosis. An axon is the part of the neuron that connects one neuronal cell body to other neurons. Scientists call the bundles of long axons the white matter tracts. The changes in the biomarkers are tiny—it is almost impossible to use them to predict if someone will develop psychosis. Yet, they can be detected, on average, when scientists compare populations of people suffering from psychosis to populations of healthy volunteers.

Risk and Protection for Psychosis (the Brain)

But again, this is not the whole story. Obviously, people who have an increased risk for psychosis have relatives with whom they share a large amount of genetic data. What about the biomarkers in these relatives’ brains? Let us compare three groups: first, relatives of people who developed psychosis (for example, siblings); second, people who suffer from psychosis; and third, people from the general population. When scientists measure biomarkers of psychosis in these groups, the relatives’ brain biomarkers are, on average, intermediate between those of the two other groups. This phenomenon can be called the risk model (Figure 2A). According to this model, relatives of people who develop psychosis are also at risk (lower, but it still exists) of developing psychosis. So, why do most family members not develop psychosis? The model suggests these relatives do not develop psychosis because they have a lower risk.

But a different model exists that can be called the protective model. The protective model suggests that there are two factors: risk factors, like those in the risk model, and some protection mechanisms present in relatives’ brains (Figure 2B). In relatives’ brains, the protection mechanisms operate in an opposite direction to the risk factors. According to this hypothesis, the relatives will not develop psychosis since their brains are both at risk and under protection. In other words, in some cases, the biomarkers measured in the first group are more different from those detected in the other two groups. Consequently, these findings might suggest a protection mechanism. For example, in one study, siblings of people with psychosis had better integrity of white matter tracts in some areas of the brain, on average, than the other two groups [2]. Another study found a similar pattern in the white matter tracts of the language system [3]. It is easy to understand why this is important. We mentioned that incomprehensible speech is a key symptom of psychosis. If the siblings have a protective mechanism in their language system, the chances that they will develop psychosis go down.

Psychosis and Creativity

The story might be even more complicated! For many years, people thought that having the positive symptoms of psychosis, like hallucinations and delusions, might be related to creativity or even genius qualities. Aristotle, the famous Greek philosopher, once said: “No great mind has ever existed without a touch of madness”. This hypothesis sounds simple. The brains of most people work in a relatively strict manner. This is a good thing—otherwise, we would probably not be able to function the way we do. Yet, thinking about new options or being creative might require some level of “freeing” the mind from its standard limitations. However, a bit too much “freedom” in the brain’s thought process can lead to a breakdown and psychosis.

People often use the story of famous, highly creative people who experienced psychosis to support this hypothesis. You might have heard about the mathematician John Nash, who was undoubtedly a mathematical genius. He won the Nobel Prize in Economics. But he also suffered from psychosis. In reality, there is little scientific evidence supporting this hypothesis. Most people suffering from psychosis are not geniuses. Similarly, most geniuses do not suffer from psychosis. Nevertheless, some evidence suggests that people with an increased risk of developing psychosis might show a higher level of creativity. However, this usually occurs if they do not actually develop psychosis. For example, the genetic risk for psychosis among Icelandic people working in creative jobs was higher than that of the general population [4].

Voice Hearing and Protection for Psychosis (the Mind)

We can look at this relationship from a different point of view—that of the mind. When we say “the mind”, we mean the thoughts and internal feelings of the person who experiences them. As we mentioned, the most common type of hallucination is hearing voices. This is often thought to be related to mental illness. And indeed, it is a common symptom in certain psychiatric conditions such as psychosis. Surprisingly, however, many well-known, influential people have heard voices. For example, the famous Greek philosophers Pythagoras and Socrates heard voices. Socrates called his voice the daimonion (“the divine”). The daimonion used to warn Socrates if he was about to do something that was not in his best interest. In fact, quite some people regularly hear voices, and many appreciate their voices and do not want treatment for them. Why is this?

One study asked both patients with psychosis and healthy people who heard voices about those voices. The researchers found that both groups heard, on average, 8–11 distinct voices at the same loudness level. However, the people with psychosis heard voices that lasted much longer, on average, 40 min, while the voices healthy people heard lasted an average of 2–3 min. The patients also had less control over their voices. They could not make their voices go away. By contrast, healthy people usually can make their voices go away. The voices of the patients were also often unpleasant. By contrast, the voices of healthy people were not. Thus, psychosis patients heard long, unpleasant voices that they could not make go away. By contrast, the healthy people heard short, neutral, or pleasant voices that they could control.

It is easy to see how this makes a difference. The healthy people had almost no discomfort or disruption to their lives due to their voices, while the patient group did (Figure 3). Moreover, both voice-hearing groups endured more emotional abuse during childhood than healthy people who did not hear voices. Examples of emotional abuse can be parents constantly yelling at and bullying their kids. Both groups also experienced, on average, more sexual abuse as children. Because of this, some researchers think that hearing voices is a response to childhood trauma—hearing voices might be the brain’s coping mechanism. It is possible that hearing voices leads to more submissive and other protective behavior, which helped them in their childhood years to avoid experiencing more trauma [5]. This effect can work if the voices are relatively short, not unpleasant, and can be controlled. In that case, they can reduce stress and protect the mind. Consequently, when those children grow up, they will have a reduced probability of developing psychosis. But if voices are long, unpleasant, and cannot be controlled, this could increase stress and thus lead to psychosis.

Summary

In summary, psychosis is a serious mental condition influenced by both a person’s genes and environment. Still, not everyone at high risk develops it. It might be that some compensatory or protective mechanisms exist for people who are at risk of developing psychosis and do not develop it. However, this probably only occurs if the risk is not too high. These protection mechanisms exist both on the mind level (voice-hearing) and the brain level (biomarkers). Future studies will show if this is indeed the case.

Glossary

Psychosis: ↑ A psychiatric mental condition that affects people. People suffering from psychosis often suffer from delusions or hallucinations. Also called schizophrenia.

Cognitive: ↑ Relating to or involving intellectual activity (such as thinking, reasoning, or remembering).

Hallucinations: ↑ Images, voices, smells, or touch that are experienced without an external cause.

Delusion: ↑ A belief in something untrue, even when clear evidence or reasoning shows it is not real.

Biomarker: ↑ A measurable feature in the body that helps identify a specific condition. For example, the number of red blood cells or the levels of certain molecules in body fluids can serve as biomarkers.

Risk Model: ↑ A hypothesis concerning the development of psychosis that stresses the risk (especially genetic ones) of developing the condition.

Protective Model: ↑ A hypothesis concerning the development of psychosis that stresses both risk factors and protection mechanisms.

Voice Hearing: ↑ A case where someone hears voices or utterances in the absence of any speaker; Scientists and psychiatrists sometimes refer to the experience as auditory verbal hallucinations.

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

The authors would like to thank all the participants that took part in their studies (whether voice-hearers, people with mental problem, or people form the general population).

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