Schizophrenia: Causes, Risk Factors & Symptoms

Causes

The cause of schizophrenia is unknown. Problems with brain structure and chemistry are thought to play a role. There also appears to be a genetic component. People with a parent or sibling with schizophrenia have a 5%-10% chance of developing the disease. This compares to a 1% chance if no relatives have schizophrenia.

Some researchers believe that environmental factors may contribute to the development of schizophrenia. They theorize that a fetal viral infection and/or difficult birth or obstetrical trauma may trigger schizophrenia in people who are predisposed.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Schizophrenia does not develop because of one risk factor. Rather, it develops because of how your genes and environment interact. You may have a gene that increases your chance of schizophrenia, but may or may not develop the disease based on your environment. Environment in this case means any outside factors like stress or infection. Factors that increase your risk of schizophrenia include:

• Having a parent or sibling with schizophrenia
• Marijuana use
• Abnormal brain structure
• In the northern hemisphere: being born during winter months; being born in the city
• Infection
  • Respiratory
  • Influenza
  • Polio
• Oxygen deprivation during pregnancy
• Maternal depression
• Issues at birth such as:
  • Long labor
  • Bleeding during pregnancy
  • Prematurity
  • Low birth weight
  • Maternal malnutrition
  • Congenital deafness
  • Infections during pregnancy
• Loss of a parent during childhood
• Financial stress

Men typically develop symptoms in their late teens or early twenties, while onset for women tends to occur in their twenties or thirties. In rare cases, it is seen in childhood.

Symptoms

Symptoms usually start in adolescence or early adulthood. They often appear slowly and become more disturbing and bizarre over time, or they may occur in a matter of weeks or months.Symptoms include:

• Hallucinations—seeing or hearing things/voices that are not there
• Delusions—strong but false personal beliefs that are not based in reality
• Disorganized thinking
• Disorganized speech—lack of ability to speak in a way that makes sense or carry a conversation
• Catatonic behavior—slow movement, repeating rhythmic gestures, pacing, walking in circles, negativism, repetitive speech
• Emotional flatness—flat speech, lack of facial expression, and general disinterest and withdrawal
• Paranoia—a psychosis characterized by systematized delusions of persecution or grandeur
• Inappropriate laughter
• Poor hygiene and self-care

Associated conditions include:

• Obsessive-compulsive disorder
• Substance abuse (of drugs, alcohol, caffeine, nicotine)
• Self-injury, including suicide