Mental illness is characterized by uncontrollable and unusual thoughts, feelings and actions. While almost everyone experiences mood swings or can sometimes find it hard to think clearly, people with mental illnesses have severe symptoms that damage their ability to function in everyday life.
Common layman’s terms for mental illness are mental disorders, psychotic illnesses, psychiatric illnesses, neurosis and nervous breakdowns, but these are not all medical terms. Insanity is a legal term referring to a state in which a person is so impaired or out of touch with reality that he or she cannot be held legally responsible for a crime.
Mental illness is still not completely understood, but the prevailing theory today is that a combination of genetics and environmental factors cause disturbances in the neurobiology of the brain. Doctors have to rule out medical conditions such as thyroid disorders, hormonal imbalances, brain tumors, head trauma, exposure to toxic chemicals, changes in blood sugar levels and reactions to surgery before they can diagnose someone as mentally ill.
There are about 100 kinds of mental illness, but some of the main forms are disorders characterized by anxiety (e.g. panic disorder, Post Traumatic Stress Syndrome), psychosis, poor impulse control (e.g. pathological gambling, kleptomania, pyromania), problems with mood (e.g. depression, bipolar disorder) and hypochondria.
Dissociative disorders can include a loss or change of identity and memory and include multiple personality disorder and amnesia. Personality disorders are characterized by a pattern of maladaptive behaviors. Kinds of personality disorders include paranoid, schizoid, borderline, histrionic, narcissistic, antisocial, avoidant, dependent and obsessive compulsive.
Substance abuse disorders are characterized by an inability to stop using alcohol, drugs, other substances or certain activities even when such use is damaging one’s life, and even when one wants to quit doing so. Substance abuse disorders are considered mental illnesses.