Schizophrenia is a serious mental illness characterized by significant alterations in a person’s perception of reality, thought processes, and behavior. This condition profoundly impacts an individual’s ability to think clearly, manage their emotions, and relate to others, often emerging in late adolescence or early adulthood. Symptoms are typically grouped into categories based on the type of functional change they represent. These groupings help clinicians recognize the full range of experiences associated with the illness and guide effective treatment strategies.
Defining Positive Symptoms
The term “positive symptom” does not imply that the experience is beneficial or desirable. Instead, “positive” refers to the presence or addition of experiences, thoughts, or behaviors not typically found in healthy individuals. These symptoms are an excess or distortion of normal mental functions, representing a break from shared reality, often termed psychosis. Positive symptoms are a defining feature of the active phase of the illness and are often the most apparent and disruptive manifestations of schizophrenia.
Primary Manifestations: Delusions and Hallucinations
Two of the most recognized and impactful positive symptoms are delusions and hallucinations, which represent a significant departure from reality. Delusions are strongly held, fixed beliefs that are not based in reality and persist even when the person is presented with clear evidence to the contrary. These false beliefs can take many forms, often involving a theme of fear, grandiosity, or bodily changes.
Delusions
A person may experience persecutory delusions, believing they are being spied on, harassed, or harmed by others despite a lack of evidence. Conversely, grandiose delusions involve a false belief in one’s own exceptional abilities, wealth, or power, such as believing they are a famous historical figure or have supernatural capabilities. Delusions of reference are also common, where an individual believes that certain gestures, comments, or environmental cues, like a news report, are specifically directed at them.
Hallucinations
Hallucinations are sensory experiences that occur without any external stimulus, meaning a person perceives something that others do not. They can affect any of the five senses, but auditory hallucinations are the most common type in schizophrenia. Auditory hallucinations often involve hearing voices, which may be critical, commanding, or conversational, and can significantly influence the person’s mood and actions.
Visual hallucinations involve seeing things that are not present, such as objects, people, or lights. Tactile hallucinations create the sensation of being touched or having something moving on or under the skin. Olfactory and gustatory hallucinations involve perceiving non-existent smells or tastes, which can sometimes lead to the false belief that food is poisoned. Approximately 70% of individuals with schizophrenia will experience hallucinations at some point during their illness.
Other Positive Symptom Expressions
Beyond delusions and hallucinations, other positive symptoms relate to disorganized thought processes and unusual motor behaviors. Disorganized thinking, also known as formal thought disorder, is a disruption in the structure of thought, which manifests primarily in speech. This can involve thoughts rapidly jumping from one unrelated idea to another, a phenomenon called derailment or loosening of associations.
Disorganized Thinking
In severe cases, speech may become so disorganized that it is nearly incomprehensible, sometimes referred to as “word salad”—a jumble of unrelated words and phrases. The person may also struggle to maintain focus or may stop mid-sentence, making conversations difficult for others to follow. This impaired ability to organize thoughts reflects a core cognitive disturbance of the disorder.
Abnormal Motor Behavior
Another category of positive symptoms includes grossly disorganized or abnormal motor behavior. This ranges from childlike silliness and unpredictable agitation to extremes of reduced responsiveness. The most severe form of this motor disturbance is catatonia, which involves symptoms from a state of near-unresponsiveness (stupor) to excited, purposeless agitation.
Catatonic symptoms can include adopting and maintaining bizarre postures, exhibiting waxy flexibility where limbs remain in positions they are placed, or engaging in repetitive, seemingly meaningless movements. While catatonia can occur with various conditions, it is closely tied to schizophrenia, with up to 35% of people experiencing catatonic symptoms at some point. These motor symptoms significantly interfere with daily functioning.
Distinguishing Positive from Negative Symptoms
To fully grasp the nature of positive symptoms, it is helpful to contrast them with the other major category of schizophrenia symptoms: negative symptoms. While positive symptoms are defined by the presence of abnormal experiences, negative symptoms are defined by the absence or deficit of normal functions and abilities. They represent a subtraction from a person’s typical emotional and behavioral repertoire, such as a reduced ability to initiate activities or express emotion.
Negative symptoms include avolition (a decrease in the motivation to pursue purposeful goals) and alogia (a poverty of speech). They also include diminished emotional expression, sometimes called flat affect, which is a reduction in the visible display of emotion through facial expression or vocal tone. The distinction is crucial because positive symptoms are generally more responsive to antipsychotic medication, while negative symptoms are often more persistent and challenging to treat.