Schizophrenia and its Possible Cause

• 07 Aug 2020

Why in News

Recently, the Schizophrenia Research Foundation (SCARF) and Jeevan Stem Cell Foundation, Chennai have carried out a pilot study on people of specific ethnicity with schizophrenia.

• The study finds an association of specific alleles (variants of specific genes) with the disease.

Schizophrenia

• It is the descriptive term for a group of psychotic disorders in which personal, social and occupational functioning deteriorate as a result of disturbed thought processes, strange perceptions, unusual emotional states, and motor abnormalities.
• It is a debilitating (making someone very weak and infirm) disorder. The social and psychological costs of schizophrenia are tremendous, both to patients as well as to their families and society.
• Onset: It typically begins in late adolescence or early adulthood.
• Symptoms:
  
  • Positive Symptoms: These are pathological excesses or bizarre additions to a person’s behaviour like delusions, disorganised thinking and speech, heightened perception and hallucinations and inappropriate affects.
  • Negative Symptoms: These are pathological deficits and include poverty of speech, blunted and flat affect (Showing less or no emotions), loss of volition (inability to start or complete a course of action) and social withdrawal.
  • Psychomotor Symptoms: Less spontaneous moves or making odd grimaces (extremely distorted and particular facial expression) and gestures.
• Causes:
  
  • Schizophrenia’s cause is not exactly known yet. There are various studies among groups of varied ethnicities across the world, on the possible causes and other relations.
    
    • These studies have shown associations of the disease with different alleles related to the Human Leukocyte Antigen (HLA).
      
      • HLA is an important part of the immune system and related to a group of genes on chromosome six.
      • HLA genes are extremely variable and are very different across human populations.
    • However, the specific allele that was found to be associated with schizophrenia varied from group to group.
• Treatment:
  
  • Therapy and support can help people learn social skills, cope with stress, identify early warning signs of relapse and prolong periods of remission.

Key Points

• Findings of the Current Study:
  
  • It holds that HLA is important for the proper functioning of the immune system and its variations can lead to immunological abnormalities.
    
    • In autoimmune diseases, when the body creates antibodies against the NMDA receptors in the brain, these antibodies disrupt normal brain signalling and cause brain swelling or encephalitis affecting both men and women and can lead to schizophrenia.
      
      • The N-methyl-D-aspartate (NDMA) receptor is a glutamate receptor and ion channel protein found in nerve cells and is important for memory functions.
  • Researchers found a higher frequency of HLA class I alleles in individuals with schizophrenia.
    
    • Individuals carrying these alleles could be susceptible to schizophrenia.
  • They also found a negative correlation with some alleles which were found in lower frequency in individuals with schizophrenia.
    
    • These could be protective alleles in schizophrenia.
  • For the first time, the amino acids level in HLA molecules among the patients were also studied.
  • Researchers held that the reasons or causes for schizophrenia are not entirely clear, but perhaps selection and ‘memory’ of past selection pressures (infections) play a role in its onset.
    
    • However, there is a need for further studies of the exact factors causing the disorder. The occurrence of different alleles itself is not a problem but finding the exact allele causing it, is a challenge.
• Earlier studies had indicated that different alleles may be involved in different ethnic groups. For example, studies in Saudi Arabia, Tunisia and Japan point to involvement of different alleles responsible for risk factor to schizophrenia.

Source: TH