What is schizophrenia? - Anees Bahji

Summary

Schizophrenia was identified more than a century ago, but its exact causes remain unknown. It is considered a syndrome: a group of related disorders with similar symptoms that may have different causes. Symptoms vary from person to person, and early changes—such as irritability, subtle shifts in personality, or unusual thoughts—can be difficult to recognize.

Symptoms

A first psychotic episode often occurs in late adolescence or early adulthood, typically earlier for men than for women. Symptoms fall into three broad categories:

• Positive symptoms: Experiences or behaviors not generally present in the broader population, including delusions, hallucinations, and disorganized speech or behavior.
• Negative symptoms: Reduced motivation, emotional expression, or speech.
• Cognitive symptoms: Difficulties with concentration, memory, and decision-making.

Schizophrenia does not mean having multiple personalities. Rather, its symptoms involve disruptions in thought processes.

Causes and risk factors

Schizophrenia likely arises from a combination of genetic and environmental factors, rather than a single cause.

• Genetics: Schizophrenia has strong genetic links. While about 1% of people are affected, children or siblings of someone with schizophrenia are described as ten times more likely to develop it. An identical twin has about a 40% chance. Multiple genes are likely involved, but the specific genes and their number are not known.
• Environment: Possible factors include exposure to certain viruses in early infancy and the use of some drugs, including marijuana, which may trigger psychosis in highly susceptible people.
• Combined risk: Environmental factors do not affect everyone equally. Their impact may depend on a person’s underlying genetic risk.

Treatment and the brain

Antipsychotic drugs have helped researchers investigate brain signaling associated with schizophrenia.

• Traditional antipsychotics block dopamine receptors. They can reduce positive symptoms, which are linked to excess dopamine activity in particular brain pathways, but may worsen negative symptoms, which may be related to too little dopamine activity in other areas.
• Newer antipsychotics target multiple neurotransmitters, including serotonin as well as dopamine. They may address some limitations, though medications can also cause side effects, such as weight gain.
• Some people with schizophrenia show loss of neural tissue, but it is unclear whether this results from the illness or from drug-induced suppression of signaling.
• Antipsychotics combined with other interventions, such as cognitive-behavioral therapy, can be effective.
• Electroconvulsive therapy may provide relatively short-lived relief and can be effective, particularly when other treatments have not worked.
• Early intervention matters: Long periods of untreated psychosis may allow some psychotic experiences to become embedded in a person’s personality.

Stigma and access to care

Stigma can discourage people from seeking help. Despite the perception that people with schizophrenia are dangerous, they are more likely to be victims of violence than perpetrators. Appropriate treatment may help reduce the likelihood of violence associated with schizophrenia. Education for patients, families, and communities can help counter stigma and improve access to treatment.

Speakers and sources featured

• Anees Bahji — Credited as the lesson’s author and the source of the video’s explanatory narration.
• TED-Ed — The educational video’s publisher.