Characteristics of Schizophrenia

GENERAL CHARACTERISTICS OF SCHIZOPHRENIA

  • Schizophrenia is a severe and chronic mental disorder characterised by disturbances in thought, perception, and behaviour.
  • People with schizophrenia commonly experience hallucinations (seeing, hearing, or otherwise sensing things that aren’t there), and delusions (strongly held beliefs that aren’t based in reality).
  • They may also exhibit disorganised speech or behaviour and decreased participation in daily activities.

SPECIFIC SYMPTOMS AND CLASSIFICATIONS

Positive Symptoms

  • Labelled as ‘positive’ because they represent additional behaviours not seen in the general population. These include:
    • Hallucinations, the most common being auditory, followed by visual.
    • Delusions including paranoid delusions (believing others are plotting against them) and delusions of grandeur (believing they have special powers or are famous).
    • Thought disorder, which involves difficulty organising thoughts or connecting them logically. Speech may be garbled or hard to understand.

Negative Symptoms

  • These are deficits of normal emotional and behavioural functioning:
    • Avolition (or apathy), a lack of initiative or persistence.
    • Anhedonia, the inability to experience pleasure.
    • Alogia, diminished speech output.
    • Flat affect, lack of emotional expression during conversation.

Cognitive Symptoms

  • These symptoms often make it hard to lead a normal life and include:
    • Disorganised thinking, where the person might have trouble organising their thoughts or connecting them logically.
    • Impairments in working memory, problem-solving, and attention.

DIAGNOSIS AND CRITERIA

  • The DSM-5 criteria for a diagnosis of schizophrenia includes at least two of the following symptoms for a significant portion of time during a 1-month period: hallucinations, delusions, disorganised speech, disorganised behaviour, and negative symptoms.
  • At least one of the symptoms must be one of the first three listed above.
  • Additionally, the person must show continuous signs of the disturbance for at least 6 months, with at least 1 month of active symptoms.

EPIDEMIOLOGY AND PROGNOSIS

  • Schizophrenia affects about 1% of people worldwide.
  • The condition usually begins in late adolescence or early adulthood, with men tending to show symptoms earlier than women.
  • The course of the illness is typically chronic, and while some individuals may experience only a single episode, most suffer from recurring episodes of psychosis and may continue to display some level of impaired functioning.

AETIOLOGY

  • Experts generally agree that, while the exact cause of schizophrenia remains unknown, it is likely due to a combination of genetic, biochemical, and environmental factors.
  • Family, twin, and adoption studies provide evidence for the role of genetics in the transmission of schizophrenia.
  • Dysfunction in the dopamine system is believed to play a significant role in the disorder.
  • Environmental risk factors may include complications during pregnancy or birth, viral infections, psychosocial factors, and drug use.