Although the specific causes of mental illnesses are not known, it is becoming clear over research that many of these illnesses are caused by a combination of psychological, biological, and environmental factors.
Biological Factors behind Mental Illness
Some mental illnesses are associated with abnormal functioning of nerve cell pathways or circuits that connect specific brain regions. Nerve cells within the brain pathways converse through chemicals called neurotransmitters. “Tweaking” these chemicals — through psychotherapy, medicines, or other medical procedures — can help pathways run more proficiently. In addition, weakness or injuries to certain regions of the brain have also been associated with some mental conditions.
Some other biological factors that contribute to these illnesses are the following:
Mental illnesses also run in families, signifying that individuals who have a family member with a mental illness may be to a greater extent at risk of developing them. Probability in families is passed on through genes. Specialists found that many mental illnesses are associated with abnormalities in some genes rather than just one or a few and how these genes respond to environmental factors are different for every individual (even identical twins). That is why an individual inherits a vulnerability to a mental illness and doesn’t certainly develop the illness. Mental illness itself arises from the combination of multiple genes and other factors — such as a traumatic event, abuse, or stress — which can affect, or trigger, a condition in an individual who has an inherited exposure to it.
Many infections are associated with damage to the brain in turn resulting in a mental illness or worsening of a previous illness. For example, a disorder known as pediatric autoimmune neuropsychiatric disorder developed because of the Streptococcus bacteria has been associated with the development of obsessive-compulsive disorder in children and other mental illnesses.
Brain defects or injury
Defects in or injuries to certain regions of the brain have also been associated with some mental illnesses.
Some evidence suggests that interference in the development of the early fetal brain or any trauma at the time of birth — for example, lack of oxygen in brain cells — may be a factor in the occurrence of certain illnesses, e.g. autism spectrum disorder.
Long-term substance abuse has also been linked to paranoia, depression, and anxiety.
Exposure to toxins such as lead plays a great role in developing mental illnesses. Poor nutrition also contributes to their development.
Psychological Factors behind Mental Illness
Psychological factors behind the development of mental illnesses include:
- Severe psychological trauma in childhood, such as sexual abuse, and physical or emotional disturbance.
- Big loss at in early age, such as the loss of a parent
- Reduced ability to relate to others
Environmental Factors behind Mental Illness
Some stressors can prompt an illness in an individual who is susceptible to any mental illness. These stressors include:
- Dysfunctional family life
- Feelings of insufficiency, low self-esteem, anger, loneliness, or anxiety
- Changing schools or jobs
- Death or divorce
- Cultural or social expectations
- Any type of substance abuse by the individual or his parents.