 What is it like to have schizophrenia? The experience of schizophrenia is not one that most people will easily understand. It's not like depression, where most of the symptoms, like insomnia or fatigue, will be instantly familiar to most people. With schizophrenia, the most prominent symptoms of the disorder, the delusions, hallucinations, and disorganized thoughts don't have any direct parallels in our own lives. Because of this, schizophrenia is hard to understand, leading to misinformation, misconceptions, and misdiagnoses. To improve our understanding of this disease, we need to do much more than simply memorize lists of symptoms. Instead, we need to learn the underlying mechanisms of schizophrenia so that we can better recognize it when we see it in our patients. Some have hypothesized that the core deficit in schizophrenia involves the concept of salience. Salience is the interestingness of information, or how important we perceive that information to be. We give salient items more attention, and are more likely to act upon them. If I were to tell you 10 random numbers, say, 1-5-5-8-3-7-8-2-9-0, but not tell you anything about them, you probably wouldn't find them particularly salient. Without that salience, they will likely drop from your attention, and quickly be forgotten. However, if I told you that these numbers are from tomorrow's winning lottery ticket, and that there's still time to enter, then suddenly they become very interesting indeed. By telling you this, I have increased the salience of the information. The numbers themselves have not changed at all. Only their salience has changed. On a biological level, the neurotransmitter dopamine plays a key role in the process of salience. When information is found to be salient, your brain releases dopamine. This rush of dopamine makes you pay more attention to the information and motivates you to act upon it. We can manipulate the salience of information by tying it to some kind of a reward. Take the ticker on the New York Stock Exchange as an example. Someone who is unfamiliar with the financial system would likely find the constant stream of letters and numbers to be meaningless or random. For stockbrokers, however, the ticker is incredibly salient because stockbrokers believe that these letters and numbers will potentially allow them to make millions of dollars. This information has been made salient by connecting it to the possibility of reward. Information can also be made salient by linking it to a negative outcome. For example, public safety experts trying to encourage helmet use will often use grisly footage of motorcycle accidents as a way of getting your attention. A video like this is disturbing on a visceral level, yet it is also effective at increasing the salience of their message and motivating people to act differently so they can avoid a similar outcome. Our brains use salience to filter incoming information. We take in an enormous amount of information every day. Within 30 minutes of waking up, most of us have already read the news, checked the weather forecast, browsed social media, and listened to music. If we gave our full attention to all of these things, we would quickly become overwhelmed and incapacitated. Instead, we quickly move on from information that has no direct relevance to us. From this morning's information, your brain might interpret only the weather report as salient, as forgetting to bring an umbrella will leave you cold, wet, and miserable. The other information is found to have no particular significance, so it is filtered out and quickly forgotten. This is a complex process, yet our brains do it instantly, automatically, and unconsciously, thousands of times per day. So how does this relate to schizophrenia? People with schizophrenia are believed to be in a state of aberrant salience, characterized by excessive and illogical release of dopamine. When dopamine is flowing in this way, salience is assigned to every bit of new information without any clear connection to rewards or punishments. It would be like suddenly entering a world where every letter and number had the potential to make you a million dollars, or where every decision had the life or death consequences of a motorcycle accident. People in the early stages of schizophrenia describe being in a state like this. They say things like, My senses were sharpened, I developed a greater awareness of the world, and became fascinated by the little insignificant things around me. Sights and sounds possessed a keenness that I had never experienced before. It was as if parts of my brain awoke, which had been dormant. My senses seemed alive. Things seemed clear-cut. I noticed things I had never noticed before. I felt that there was some overwhelming significance in this. I felt like I was putting a piece of the puzzle together. This makes life initially quite vivid and dramatic for someone in a state of aberrant salience, yet it rapidly becomes a confusing and unbearable way to live. Normally, we can figure out why our brain is telling us that something is important. We know that paying attention to the weather forecast will help us to avoid having a bad day. However, someone in a state of aberrant salience will perceive a sense of overwhelming significance in all of their experiences without being able to understand why. Why me, they ask. Why now? Why does this all seem so important? To make sense out of this experience, people with schizophrenia will begin to develop explanations for why each piece of information suddenly feels so important, so relevant, so personally significant. If they watch the news in this state of heightened salience, they might come to believe that the president must be using their state of the union address to communicate a special coded message meant only for them. When listening to music, they may get the feeling that there must be a reason why that particular song came on the radio at that exact moment. On the internet, any random stimulus, say a pop-up ad about a new brand of lotion, may seem so special and compelling that it must somehow be the key to saving the world. To everyone else, these ideas sound, frankly, psychotic. For a person in a state of aberrant salience, however, these delusions of reference help them to make sense out of a senseless mental environment where everything, everywhere, seems to have some life-changing importance. If delusions develop when excessive salience is given to external stimuli, then what happens when salience is given to internally generated information? After all, everyone has an internal stream of consciousness that we generally recognize as being our own. In a state of aberrant salience, however, these thoughts can seem important to the point where they are given the same level of priority as a voice coming from outside your head. This is thought to be the mechanism for the auditory hallucinations that people with schizophrenia experience. It is as if the volume of these internal thoughts has been turned up so far that they grab your attention in the same way as hearing your name yelled from across the room. Aberrant salience can also explain the profound thought disorganization that is another hallmark of schizophrenia. People with schizophrenia often have difficulty understanding even seemingly simple concepts and ideas. They may hear the same information over and over again, but show no sign of actually comprehending it. They can respond to their environment in ways that make little sense to an outside observer. This disorganization of thoughts, speech, and behavior makes more sense when you consider that aberrant salience leaves people in a state of perpetual information overload. When the filter of salience breaks, you become constantly bombarded by new information every second of the day with no way of making sense of it all. It would be like trying to watch dozens of TV shows all at the same time. In this state of confusion, it is no wonder that people with schizophrenia can appear so bewildered and distracted by even simple concepts. They say that the value of a theory lies in how well it is able to explain what we observe, and aberrant salience appears to pass this test. It provides a framework for answering many of the questions we have had about schizophrenia for centuries. For example, we have long wondered why the content of delusions in schizophrenia varies so drastically from culture to culture. Someone in a modern city is more likely to believe that satellite waves are broadcasting their thoughts than someone from a rural area who is more likely to say that their thoughts are being stolen by a neighbor's curse. Yet, if schizophrenia is an illness with a biological basis, shouldn't the symptoms be similar across cultures? The concept of aberrant salience bridges this gap by arguing that delusions are normal psychological constructs generated by a person in an abnormal biological state. If delusions are psychological constructs, it makes sense that they would draw upon that person's own unique experiences and cultural values, even if the underlying biological abnormality is the same. The concept of aberrant salience can inform not only our understanding of schizophrenia, but also how we treat it. If aberrant salience is associated with excess dopamine, then using medications to block dopamine should reduce the symptoms of schizophrenia. This appears to be true. All of the drugs prescribed for schizophrenia, known as antipsychotic medications, block dopamine receptors to some degree. This creates a state of dampened salience where information lacks the power to capture attention that it once had, leading to reductions in symptoms like delusions, hallucinations, and thought disorganization. However, this comes at a cost. Like many medications, antipsychotics are non-specific in their actions. They cause a global dampening of salience for all information that the brain processes, not just information related to psychosis. When preparing for their day, a person taking antipsychotic medications would avoid assigning salience to irrelevant stimuli, such as pop-up ads or a song on the radio. This is an improvement. However, they also would have difficulty assigning salience even to relevant information, like the weather report, and may then forget to bring their umbrella. This shows both the power and the limitations of using antipsychotics to treat schizophrenia. They reverse the excess of dopamine driving a state of aberrant salience, but in doing so, they can interfere with the normal functioning of salience as well. Understanding the concept of aberrant salience can be illuminating for people trying to learn about schizophrenia. However, it is not without its limitations. It does a much better job of explaining the dramatic positive symptoms of schizophrenia, like delusions, hallucinations, and thought disorganization, than it does explaining the negative symptoms like flat emotions, inability to feel pleasure, and difficulty forming relationships that are often more impairing for people with schizophrenia. The concept of aberrant salience is also silent on the question of why some people develop schizophrenia while others do not. It only explains what happens once an episode of psychosis has already begun. It is likely that no single theory will explain the disease as complex as schizophrenia. There are, without a doubt, multiple mechanisms to be discovered. What is it like to have schizophrenia? Schizophrenia is so much more than just a list of symptoms. The concept of aberrant salience gives us a better glimpse into the complex and multifaceted lives of our patients. It allows us to see that people with schizophrenia are not some alien other that we will never understand. Rather, it shows us that the symptoms of schizophrenia are rooted in thought processes that every human being can understand and relate to. It underscores the shared humanity we have, even with people who act and speak in ways that we cannot comprehend. We are ultimately more alike than we are different. If more people understood this, perhaps there would be less of the fear and stigma that has dominated the discussion about schizophrenia for so long. Hi everyone, I hope you gained something from this latest video. I strongly encourage anyone with an interest in schizophrenia, or mental health in general, to read the paper that inspired this talk. I'll put the link down in the description. As always, if you have any thoughts on this video, or suggestions for future content, let me know. You can also check out my other videos on YouTube, or my book Memorable Psychopharmacology on Amazon. Thanks for watching.