What are the differences between positive and negative neurological symptoms?

From the Guidelines

Neurological symptoms in schizophrenia can be broadly categorized into positive symptoms, which are an excess of normal function, and negative symptoms, which represent a loss or reduction of normal function. The distinction between these two types of symptoms is crucial for guiding treatment approaches. According to the study published in 2021 1, positive symptoms in schizophrenia include hallucinations, delusions, and disorganized behavior, which are present in excess in individuals with schizophrenia compared to those without the disorder. On the other hand, negative symptoms include increased apathy, avolition, and anhedonia, leading to isolation or self-neglect, and are characterized by reduced functioning in domains where individuals without schizophrenia function normally. Some key differences between positive and negative symptoms are:

• Positive symptoms are often more responsive to antipsychotic medications, which can help reduce the excess neural activity associated with these symptoms 1.
• Negative symptoms, however, may not respond as well to antipsychotics and may require alternative treatment approaches, such as rehabilitative strategies or therapies aimed at improving cognitive function and social skills 1.
• The assessment of positive and negative symptoms is typically done using the Positive and Negative Syndrome Scale, where lower numbers indicate fewer symptoms 1. It is essential to accurately identify and differentiate between positive and negative symptoms to develop an effective treatment plan for individuals with schizophrenia, as the treatment approaches for these two types of symptoms can differ significantly.

From the FDA Drug Label

The BPRS psychosis cluster (conceptual disorganization, hallucinatory behavior, suspiciousness, and unusual thought content) is considered a particularly useful subset for assessing actively psychotic schizophrenic patients The Positive and Negative Syndrome Scale (PANSS) and the Scale for Assessing Negative Symptoms (SANS) were employed

The main differences between positive and negative neurological symptoms are:

• Positive symptoms include:
  • Hallucinations
  • Delusions
  • Disorganized thinking
  • Aggressive behavior
• Negative symptoms include:
  • Apathy
  • Lack of emotion
  • Social withdrawal
  • Poverty of speech These symptoms are assessed using scales such as the PANSS and SANS 2, 3

From the Research

Differences between Positive and Negative Neurological Symptoms

• Positive neurological symptoms refer to the presence of abnormal signs or symptoms that are inconsistent with a defined neurological disease, such as functional weakness or non-epileptic seizures 4, 5.
• Negative neurological symptoms, on the other hand, refer to the absence of expected neurological signs or symptoms, which can make diagnosis more challenging 6, 7.

Diagnostic Considerations

• The Diagnostic and Statistical Manual of Mental Disorders, DSM-5, emphasizes the importance of identifying positive neurological signs, such as incongruities between neurological symptoms and neurophysiological patterns of dysfunction, to diagnose functional neurological symptom disorder 6, 8.
• In contrast, the International Classification of Diseases, ICD-10, requires evidence of concurrent psychological distress to diagnose conversion disorder 6.
• A comprehensive diagnostic approach should include both positive and negative neurological signs, as well as psychological assessments, to increase diagnostic certainty 6, 7.

Clinical Implications

• The presence of positive neurological symptoms can be an important diagnostic clue, and clinicians should be aware of the potential pitfalls in diagnosing functional neurological disorders 7.
• A positive diagnostic process, which focuses on identifying the presence of specific symptoms or signs, can be a useful approach in diagnosing and managing functional neurological disorders 4, 8.