Negative Symptoms in Schizophrenia: Avolition and Occam’s Razor
The identification of schizophrenia’s negative symptoms dates back to the earliest descriptions of Kraepelin and Bleuler, who each highlighted the central role of avolition in the phenomenology and course of this illness. Since, there have been numerous advances in our understanding of schizophrenia, and the present review tracks the changes that have taken place in our understanding of negative symptoms, their description and measurement. That these symptoms represent a distinct domain of the illness is discussed in the context of their ties to other symptoms and functional outcome. The underlying structure of the negative symptom construct is explored, including several lines of investigation that point towards diminished expression and amotivation as key underlying subdomains. We also discuss findings of intact emotional experience and consummatory pleasure in individuals with schizophrenia, calling into question the **
presence of anhedonia
in this illness. We conclude with a reconceptualization of the negative symptoms, suggesting amotivation (ie, avolition) represents the critical component, particularly in regard to functional outcome. Further exploration and clarification of this core deficit will ultimately enhance our neurobiological understanding of schizophrenia, as well as strategies that may improve outcome.
What is Avolition?
Have you ever felt as though you lacked the drive to do something you wanted to accomplish? It is normal for this to happen sometimes, especially if you are tired or feeling down. However, in some people, this can become extreme and persistent. To describe these cases, we use the term avolition.
Avolition exists when a person loses the will to perform the behaviors necessary to accomplish purposeful acts, such as activities of daily living, goals, and desires. If you break the word down, you may recognize volition, which is the will and thought process that leads to deciding on and committing to certain actions. The ‘a’ in front of the word denotes a lack of this will.
Avolition can manifest as a reduction of physical energy and everyday activities, such as personal hygiene, work, school, and socialization. When it becomes persistent and exists alongside other psychological symptoms, avolition is considered a feature of certain mental disorders. Therefore, this term is usually seen in psychology and psychiatry in the context of schizophrenia, major depression, and bipolar disorder.
In this lesson, we will focus only on avolition’s link with schizophrenia. Let’s first talk about schizophrenia and how it is broken down into different types of symptoms.
How is Avolition Linked to Schizophrenia?
First, let’s briefly define schizophrenia. You have likely seen depictions of this disorder in movies. It is a genetic psychological disorder characterized by disorganized thought, confusion about reality, hallucinations, and delusions. It also includes reduced socialization, emotions, and activity. The disorder occurs in approximately 1% of the general population, but this percentage skyrockets up to 10% if it already exists in a family. Typically, schizophrenia’s symptoms are broken down into positive symptoms and negative symptoms.
The positive symptoms can be thought of as added symptoms or behaviors. In other words, these are symptoms that people without schizophrenia (or other disorders) are unlikely to experience. They include:
A loss of touch with reality, also known as psychosis
Visual, auditory, gustatory (taste), olfactory (smell), and tactile (touch) hallucinations
False beliefs, also known as delusions, which can include paranoia, or the belief that the person is someone other than who he or she really is
Disorganized or confused thought
Disorganized and random speech patterns that can include made-up words, called neologisms, or random words that do not make sense together
Many of these symptoms can occur with other psychological disorders, but there are particular methods of assessment and criteria for the diagnosis of schizophrenia.
Negative symptoms can be thought of as deficits in thoughts and behaviors that are considered normal. They are often described with the terms ‘lack of’ or ‘reduced.’ They are characterized by a:
Lack of emotion and/or emotional expression, also known as flat affect
Lack of pleasure and interest in previously enjoyed pursuits, also known as anhedonia
Reduced drive and desire to participate in social or other activities, also known as amotivation
Lack of desire to speak