Delusions, hallucinations, altered emotions and disorganized thoughts -- all are symptoms that someone suffering from schizophrenia can experience regularly.

Robert Levenson discussed schizophrenia, a chronic mental illness that affects one in 100 people worldwide, before an audience of about 300 in 100 Thomas on Saturday.

Schizophrenia is still very misunderstood, and the illness has a variety of symptoms that makes it difficult to diagnose and treat, Levenson, professor of pharmacology in the Penn State College of Medicine said.

Levenson's lecture, "Schizophrenia: The Broken Brain and How to Fix It," is the fourth installment in the Frontier Lecture Series.

Schizophrenia is a developmental illness beginning as early as childhood and can last throughout a patient's life, Levenson said.

Psychiatrists divide the symptoms of schizophrenia into two groups: positive and negative symptoms. Positive symptoms can include delusions and audio and visual hallucinations, Levenson said. Negative symptoms are more cognitive and emotional and can include restricted emotions, flat speech and the inability to think logically, he said.

Without treatment, symptoms can become more apparent and the patient less functional as time progresses, he said.

There are five types of schizophrenia: paranoid, disorganized, catatonic, residual and undifferentiated.

Schizophrenia is a genetic disease that could be caused by 30 or more problem genes. Environmental factors -- episodes that can influence the onset of the illness --also contribute to the illness and its effects.

Dopamine signaling problems could account for schizophrenia, Levenson said. A dysregulation that can create too much or too little dopamine could be the cause, he said. Drugs that dampen dopamine signaling tend to calm the symptoms of the illness, Levenson said.

Medicines that can be used to treat the illness are called antipsychotics. These drugs act as competitive inhibitors for dopamine, he said. Antipsychotic drugs are broken down into two categories: typical and atypical. These drugs tend to decrease anxiety, delusions and hallucinations, he said.

The drugs that treat Schizophrenia can also have negative side effects. Typical antipsychotics can cause unwanted sedation, rigidity, dry eyes and mouth, tremors and extreme restlessness, Levenson said. Atypical antipsychotics have fewer side effects compared to typical antipsychotic drugs but are more expensive and cause other health issues like weight gain and diabetes, he said.

Compliance is a difficulty in treating patients with the illness, Levenson said. The side effects are a major reason people suffering from schizophrenia stop using their medication. Once patients stop taking their medication, their symptoms can return.

Levenson said he his research will not be beneficial until an effective treatment can be found. "Eventually, we would like to see some of our research possibly uncover new targets for drugs that might be as good therapeutically without all the side effects," Levenson said.

The ultimate goal would be to understand the genetic basis of the illness and develop better drugs, he said.

Anne Andrews, assistant professor of molecular toxicology, who spoke last week for the series, said she thought the lecture was excellent. "I thought [Levenson] talked a lot about the two sides of the coin of the treatment of these disorders. One is we've come a long way in terms of what we can do for people, but the flip side is that we still have a long way to go," she said.