This video explores schizophrenia, a complex and often misunderstood mental illness. It covers the symptoms, including positive, negative, and cognitive symptoms, as well as potential genetic and environmental causes. The video also discusses treatment options, such as antipsychotic medications, and addresses common misconceptions about the disorder.

Schizophrenia was first identified more than a century ago, but we still don't know its exact causes. It remains one of the most misunderstood and stigmatized illnesses today. So let's walk through what we do know, from symptoms to causes and treatments. Schizophrenia is considered a syndrome, which means it may encompass a number of related disorders that have similar symptoms but varying causes. Every person with schizophrenia has slightly different symptoms, and the first signs can be easy to miss—subtle personality changes, irritability, or a gradual encroachment of unusual thoughts. Patients are usually diagnosed after the onset of psychosis, which typically occurs in the late teens or early 20s for men, and the late 20s or early 30s for women. A first psychotic episode can feature delusions, hallucinations, and disordered speech and behavior. These are called positive symptoms, meaning they occur in people with schizophrenia but not in the general population. It's a common misperception that people with schizophrenia have multiple personalities. But these symptoms indicate a disruption of thought processes, rather than the manifestation of another personality. Schizophrenia also has negative symptoms. These are qualities that are reduced in people with schizophrenia, such as motivation, expression of emotion, or speech. There are cognitive symptoms as well, like difficulty concentrating, remembering information, and making decisions. So what causes the onset of psychosis? There likely isn't one single cause, but a combination of genetic and environmental risk factors that contribute. Schizophrenia has some of the strongest genetic links of any psychiatric illness. Though about 1% of people have schizophrenia, children or siblings of people with schizophrenia are 10 times likelier to develop the disease, and an identical twin of someone with schizophrenia has a 40% chance of being affected. Even immediate relatives of people with schizophrenia exhibit milder versions of traits associated with the disorder, but not to an extent that requires treatment. Multiple genes almost certainly play a role, but we don't know how many or which ones. Environmental factors like exposure to certain viruses in early infancy might increase the chance that someone will develop schizophrenia. And use of some drugs, including marijuana, may trigger the onset of psychosis in highly susceptible individuals. These factors don't affect everyone the same way. For those with very low genetic risk, no amount of exposure to environmental risk factors will lead them to develop schizophrenia. For those with very high risk, moderate additional risk might tip the balance. The antipsychotic drugs used to treat schizophrenia have helped researchers work backwards to trace signatures of the disorder in the brain. Traditional antipsychotics block dopamine receptors. They can be very effective in reducing positive symptoms.