The dopamine hypothesis of schizophrenia is a scientific theory that suggests dopamine directly contributes to schizophrenia symptoms. Research on this theory and other causes of schizophrenia is ongoing.

Researchers do not yet know what precisely causes schizophrenia. Some research suggests a combination of several risk factors may make someone more likely to develop it.

Dopamine is a neurotransmitter, which is a chemical messenger and hormone that the brain makes. It plays an important role in many bodily functions.

Experts believe dopamine may play a key role in schizophrenia symptoms alongside other neurotransmitters. Therefore, having excess or not enough dopamine can cause different schizophrenia symptoms.

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Schizophrenia is a serious mental health condition that affects how a person thinks, feels, and behaves.

People with schizophrenia often experience symptoms of psychosis. These symptoms affect a person’s mind and make it appear as though they have some loss of contact with reality. They may also make it difficult for individuals to participate in usual daily activities.

Dopamine is a type of neurotransmitter, which are natural chemicals in the brain that help cells called neurons send and receive signals to each other.

Many current medication treatments for schizophrenia affect dopamine in the brain to help manage the condition’s symptoms.

Experts do not yet know what exactly causes schizophrenia. The dopamine hypothesis is one possible explanation for why people experience schizophrenia symptoms, including:

The dopamine hypothesis states that over- or under-active dopamine transmission in the brain may lead to these symptoms. Overactive dopamine transmission may lead to more positive symptoms, such as hallucinations or delusions. Conversely, underactive dopamine transmission may lead to more negative symptoms, such as flat affect and disorganization with thinking processes.

The dopamine hypothesis has been around for decades, and researchers are still studying it today.

In 2020, scientists reviewed how dopamine affects symptoms of psychosis from schizophrenia. They found that studies of clinical imaging support the dopamine hypothesis.

Another 2020 study investigated several sources of research into medication that affects dopamine in the brain. The study found that dopamine functions differently in people with schizophrenia.

However, other research has found that those with symptoms of psychosis respond to medication that does not affect dopamine.

Some research suggests the dopamine hypothesis does not completely explain how a person develops schizophrenia. A 2017 study suggests schizophrenia may occur due to complex interactions between several different neurotransmitter systems in the brain, in addition to dopamine.

In 2023, scientists also reviewed research into the function of dopamine in antipsychotic medications for schizophrenia. Antipsychotic medications help treat schizophrenia by blocking dopamine in the brain.

Researchers also noted that several other neurotransmitters may play a part in how a person experiences schizophrenia. However, they stated that experts do not yet fully understand how. More research may help understand the role that multiple neurotransmitters play in schizophrenia.

Experts believe dopamine may play a complex role in schizophrenia, while dopamine is a central factor in several aspects of a person’s behavior, as a neurotransmitter.

Researchers believe some parts of the brain may have links to various schizophrenia symptoms. These parts use dopamine as the main communicator. Therefore, experts believe having high or low dopamine levels may contribute to schizophrenia symptoms. However, other neurotransmitters may also play a role in the condition.

Healthcare professionals use antipsychotic drugs to help manage some symptoms of schizophrenia. These medications target dopamine levels.

A dopamine imbalance is having an over or underactive transmission of dopamine. Experts believe having an imbalance of dopamine in the brain may be one aspect that leads to different kinds of schizophrenia symptoms.

Having overactive dopamine transmission in certain parts of the brain can lead to positive symptoms of schizophrenia. These include:

  • hallucinations, which involve seeing or sensing things that are not there
  • delusions, which refers to having strong beliefs that are untrue or may seem irrational

Having too little dopamine in some parts of the brain can lead to negative symptoms of schizophrenia. It can also lead to problems with thinking. These both include:

  • a loss of motivation
  • a loss of interest or enjoyment in their daily activities
  • withdrawal from social life
  • difficulty showing emotions
  • difficulty functioning as they usually would
  • having trouble:
    • processing information to make decisions
    • using information immediately after learning it
    • trouble focusing, or paying attention
  • changes in certain thoughts and behaviors

However, dopamine is only one of several factors involved in causing schizophrenia symptoms. Other factors may include:

  • genetics
  • environment and life experiences
  • brain structure and function

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Schizophrenia is a mental health condition that affects how people’s behavior and how they think and feel.

Experts do not yet know the exact cause of schizophrenia.

The dopamine hypothesis of schizophrenia is a scientific theory. It suggests changes to dopamine in the brain may lead to schizophrenia symptoms.

However, researchers continue to investigate the exact cause of schizophrenia and the dopamine hypothesis of schizophrenia.

Dopamine is a neurotransmitter, a chemical that plays a role in how parts of the body communicate. Some medications for schizophrenia affect dopamine levels.

Increases in dopamine levels in certain parts of the brain may contribute to positive schizophrenia symptoms. Likewise, decreases in other parts may lead to negative symptoms and can affect a person’s thinking processes.

However, dopamine is one of several factors involved in schizophrenia symptoms. These include other neurotransmitters and several other factors.