Mental problems can range from mildly bothersome to severely disabling. Mental disorders are common; about 26 percent of American adults have a diagnosable mental disorder in a given year, according to the National Institute of Mental Health (NIMH). Additionally, one in 10 children and adolescents in the United States has serious mental and emotional disorders, as noted by the National Alliance on Mental Illness (NAMI). These disorders have a variety of causes, and cases may involve an interaction of factors.
Genetics
Many mental problems run in families, indicating a genetic component to some disorders, as explained by the Kim Foundation. These include obsessive-compulsive disorder, chronic anxiety, alcoholism, schizophrenia and more. Although people are more susceptible to a particular mental disorder if a close family member has the problem, not all family members will develop the disorder. Other environmental or psychological factors may be required for the problem to emerge.
Brain Damage
Brain damage is another physical reason for mental problems. Certain infections, for instance, are linked to the development of mental illness or worsening symptoms. There are reports that link a condition called pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS), to obsessive-compulsive disorder and other mental illnesses. Brain injuries also can have serious mental consequences, including preventing the affected person from being able to function effectively at school or work. People who have experienced severe head injuries may undergo significant personality changes, and may even develop schizophrenia or other psychotic symptoms, according to Rethink (the National Schizophrenia Fellowship in England).
Biochemical Causes
Some people with mental illness have unexplained physical changes in their brains, as found during imaging, according to the Mayo Clinic. Imaging technology may eventually help researchers discover causes for these brain abnormalities. Other brain-related causes of mental illness involve imbalances of chemicals called neurotransmitters that nerves use to communicate, and hormonal imbalances. Additionally, continued exposure to toxins such as lead and other heavy metals can result in learning disabilities, hyperactivity and other mental disorders.
Congenital Causes
Disruption to fetal brain development can lead to mental disorders. This may be caused by maternal malnutrition or substance abuse, fetal exposure to viruses, or loss of oxygen while in the womb or during birth. Conditions associated with these problems include learning disabilities, autism and schizophrenia.
Childhood and Adolescence Factors
Childhood stress and psychological trauma can result in mental problems that may not become obvious until much later. Physical or sexual abuse can be a factor in mental illness and may lead to chronic anxiety, post-traumatic stress disorder (PTSD) and even dissociative identity disorder (previously called multiple personality disorder), as explained by Rethink. Other factors in childhood that can result in mental problems include serious neglect, parental substance abuse, chronic illness of the child or a family member, or a significant loss such as the death of a parent or sibling. The Mayo Clinic notes that taking psychoactive drugs during adolescence can lead to mental disorders.
Adult Stress
Psychological stress during adulthood, as in childhood, can cause mental and emotional problems. A dysfunctional family life, substance abuse by one's partner, divorce, lack of healthy relationships, financial problems, living in an area with high crime rates, chronic illness and the death of a loved one all can result in mental issues. Chronic stress can lead to insomnia, difficulty concentrating, problems with memory and difficulty functioning well at work or in school. The Kim Foundation notes that social and cultural expectations can cause problems, such as eating disorders that result from society's obsession with thin bodies. Additionally, PTSD may affect soldiers who have been in combat, victims of violence and others who have experienced highly traumatic events.
