Mental illness covers a wide variety of disorders, from schizophrenia, depression, dementia, anxiety and self-harm to substance abuse.

These disorders can be the outcome of experiences in a person's life, from early childhood to later life events.

Some examples:

• chaotic, unsafe or dangerous environments (for example, living in a violent home, or living in a house with shedding asbestos, peeling lead paint, or toxic drinking water)
  
• early life losses or traumas
  (such as the death of a parent in childhood,or being abused or neglected)
  
• loss of social support (death of a loved one, divorce, moving away from friends and family, inability to remain active in social groups, lack of community involvement)
  
• unhealthy social conditions (poverty, homelessness, community violence, communal living with distressed people)
  
• experiences that undermine self-
  confidence (such as changes in appearance, health or functional abilities resulting in self consciousness or embarrassment)
  
• learned helplessness and negative thought patterns (chronic or repeated stressful events leading to the belief of helplessness, reinforced by lack of control over the situation)

Some examples:

• chronic illness (such as heart disease, stroke, HIV, Parkinson's, cancer, or diabetes) that seriously restrict activity
  
• sensory deficits (such as low vision or hearing loss –-- especially when glasses or hearing aids are neglected)
  
• side effects of medications (for example, blood pressure medications and numerous other drugs including herbal and over the counter medications)
  
• hormonal changes (affecting mood, energy levels and behavior)
  
• substance abuse (alcohol and many commonly prescribed drugs have depressive or sedating side effects, and the social and personal consequences of abusing these substances can contribute to mental illness and addiction problems.)
  
• genetic causes: (people with any family history of mental illness have a slightly higher risk of suffering from a mental health disorder.)
  
• biochemical causes (an imbalance in the chemistry of neurotransmitters such as serotonin causes changes in brain functioning that influence mental health)