Significant advances in the understanding and treatment of mental illnesses have brought greater recognition to this field of medicine over the past few decades. Here, Daniel K. Hall-Flavin, M.D., a psychiatrist at Mayo Clinic, Rochester, Minn., offers a modern interpretation of mental illnesses, including a look at how they're defined, the use of medications, the role of psychotherapy and how stress affects well-being.
What is mental illness?
Mental illness is a term that refers to all the different types of mental disorders, including disorders of thought, mood or behavior. These disorders cause distress and result in a reduced ability to function psychologically, socially, occupationally or interpersonally.
People who have a mental illness might have trouble handling such things as daily activities, family responsibilities, relationships, or work and school responsibilities. You can have trouble with one area or all of them, to a greater or lesser degree. And you can have more than one type of mental illness at the same time.
How is the classification of mental illnesses evolving?
Today, we classify mental disorders based on the symptoms a person experiences and the clinical features of the illness. As time goes by and we gain a clearer understanding of how specific genes interact with illness or specific behaviors, we may be able to develop a much more sophisticated classification system that is directly linked to a biologic cause, rather than just symptoms.
Some disorders with similar symptoms and clinical features are very different in terms of their underlying biology. To treat them similarly simply because they share the same symptoms may not be appropriate. We suspect, for example, that there are different types of schizophrenia, with different causes, and that they possibly respond differently to different treatments.
What are the classes of mental illness?
Our evolving understanding of genetics and how the brain works may eventually change how we classify mental illnesses. For the time being, we think of several main classes of mental illness:
- Mood disorders. These include disorders that affect how you feel, such as persistent sadness or feelings of euphoria. They include major depression and bipolar disorder (manic-depressive illness).
- Anxiety disorders. Anxiety is an emotion characterized by the anticipation of future danger or misfortune accompanied by a feeling of being ill at ease. Panic disorder, obsessive-compulsive disorder, specific phobias and generalized anxiety disorder are all examples of anxiety that's out of proportion to a situation and that significantly impacts your ability to function.
- Substance-related disorders. These include problems associated with the misuse of alcohol, nicotine, caffeine and illicit drugs.
- Psychotic disorders. These disorders impair your sense of reality. The most notable example of this is schizophrenia, although other classes of disorders can be associated with psychosis at times.
- Cognitive disorders. These disorders affect your ability to think and reason. They include delirium, dementia and memory problems. Perhaps the most well-known of these disorders is Alzheimer's disease.
- Developmental disorders. This category covers a wide range of problems that usually first begin to make themselves known in infancy, childhood or adolescence. They include autism, attention-deficit/hyperactivity disorder and learning disabilities. But just because they're all grouped in this category doesn't necessarily mean they share a common cause or that there's a relationship among the disorders.
- Personality disorders. A personality disorder is an enduring pattern of inner experience and behavior that is dysfunctional and leads to distress or impairment. Examples include borderline personality disorder, antisocial personality disorder and avoidant personality disorder.
- Other disorders. These include disorders of impulse control, sleep, sexual functioning and eating. Also included are dissociative disorders, in which a person's sense of self is disrupted, and somatoform disorders, in which there are physical symptoms in the absence of a clear physical cause, such as hypochondriasis.
Do all mental illnesses have a biological basis — a problem with the brain's chemistry?
No, not all of them. We know that many serious mental illnesses do have a strong biological basis. But that's not the entire story.
Some people, for example, might have an inherited, biological tendency to develop depression. They can experience serious depression even though no specific event triggers it. Others, however, have no known inherited tendency for depression. But if something happens, such as the death of a loved one, it can trigger major depression.
We don't yet know if the underlying neurochemical aspects of these two depressive reactions are the same. In other words, one person may have a mental illness because of their nature — their genetic vulnerabilities, their neurochemical functioning. And another person may have a mental illness because of nurture — an environmental cause that perhaps then alters their neurochemistry. Most of the time, however, it's probably a complex interaction of both nature and nurture.
With so many medications available to treat depression and other illnesses, is psychotherapy still a good option?
Yes, there is still a major role for psychotherapy in treating mental illnesses. Among the many forms of psychotherapy are brief therapy, cognitive-behavioral therapy, psychodynamic therapy, and family or couples therapy. Psychotherapy remains a very important part of treatment for many individuals and often is the treatment of choice.
Medication might be all that some people need to restore their brain chemistry to a more normal state. But for others, medication, although effective, doesn't alter the way they cope with the stress that might have contributed to their illness. Psychotherapy and education can help change coping behaviors and offer strategies to help understand and modify risk factors for illness.
Very often, a combination of medication and psychotherapy is most effective. And in some cases, medication is entirely ineffective and psychotherapy alone can help.
