What Causes Mental Illnesses?

Mental illness is probably the most misunderstood of all medical conditions. However, in the last few decades, understanding as well as acceptance of mental disorders as medical conditions by both the medical community and the public have come a long way.


But what exactly is it and what causes mental illnesses?

What Is Mental Illness?

Mental illness is any condition that affects behavior, thought and emotions. There are a wide range of recognized mental disorders ranging from extreme to mild including depression, anxiety disorder, psychosis, bipolar disorder and post traumatic stress disorder – to name just a few. There are also many different causes of mental illness.

mental illness causes


What Causes Mental Illnesses?

There are 3 main categories for the causes of mental illness. These 3 categories may interact to result in a mental illness or a single factor can result in a disorder. The causes of mental illness also affect individuals differently. For example, 2 people may experience a similar trauma and have a genetic predisposition to mental illness. One person may develop a mental disorder while the other may have better coping mechanisms and not present with a disorder.


The 3 Categories of Causes of Mental Illnesses are:


1. Biological Factors

These are factors that affect the body and brain physically and include:

  • Genetic predisposition where a mental disorder can be “inherited”. If a family member has a mental health condition, it is more likely that their children will have the same condition but not entirely predetermined.
  • Defects in the brain that are either due to an injury or congenital (that you are born with)
  • Illness or infections that cause damage to certain areas of the brain
  • Injury, illness, infections and physical trauma resulting in damage to the brain in utero (in the womb)
  • Abuse of substances such as drugs and alcohol that can result in long-term or permanent changes in the brain
  • Exposure to toxins (for example lead) that can damage the brain
  • Poor nutrition especially before birth and during childhood which can delay or prevent healthy brain development
  • Brain and body chemistry
  • Hormones

2. Environmental Factors

These factors are introduced by the outside world and are referred to as stressors. Normally, stressors will cause mental illness in a person who is genetically predisposed. Common environmental factors include:

  • Bereavement that can result from events such as death or divorce.
  • Dysfunctional family life.
  • Low self-esteem, lack of confidence or feelings of inadequacy.
  • Negative emotions such as anger and anxiety.
  • Social isolation or loneliness.
  • Moving home or changing employment.
  • Loss of employment.
  • Social pressure, discrimination or stigma.
  • Substance abuse by the individual or parents of the individual.
  • Poverty, debt and social disadvantage.

3. Psychological Factors

These are factors that affect the way the brain processes information to influence behavior. Psychological factors may result in behaviors and actions that are unconscious to an individual. These factors include:

  • Abuse including physical, sexual, mental or emotional. Abuse has the most influence when experienced at a young age or over an extended period of time.
  • Experiencing an extreme traumatic event/s such as a car accident, war, assault, rape etc.
  • An early loss such as parents during childhood.
  • Delayed social development and an inability to relate to others.
  • Neglect.
  • Stress.

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