Bipolar disorder is one of the most severe forms of mental illness. It is characterized by recurrent episodes of mania and even more often depression. The condition has a high rate of recurrence and it is dangerous if it is left untreated. If untreated, it has an approximately 15% risk of death by suicide. It is the third leading cause of death among people aged 15-24 years, and is the 6th leading cause of disability or lost years of healthy life for people aged 15-44 years. This is especially the case in the developed world.
What is bipolar disorder?
This disorder was previously known as manic depression. It is a diagnostic category, describing a class of mood disorders where person experiences states or episodes of depression or mania, hypomania, and mixed states. Left untreated, it is a severely disabling and dangerous psychiatric condition. The difference between bipolar disorder and unipolar disorder, also called major depression for the purpose of this introduction, is that bipolar disorder involves energized or activated mood states in addition to depressed mood states. The duration and intensity of mood states varies widely among people. Fluctuating from one mood state to another is called cycling or simply having mood swings. Mood swings cause impairment not only in one’s mood, but also in one’s energy level. It could also affect sleep pattern, activity level, social rhythm, and thinking abilities. Many people become fully disabled for significant periods of time and during this time have great difficulty functioning.
Causation of bipolar disorder
Bipolar disorder is a life-long disease and runs in families but has a complex mode of inheritance, where family, twin, and adoption studies suggest genetic factors. The concordance rate for monozygotic or identical twins is 43%, whereas it is only 6% for dizygotic twins. About half of all patients with bipolar disorder have one parent who also has a mood disorder, usually a major depressive disorder.
If one parent has bipolar disorder, the child will have a 25% chance of developing a mood disorder and about half of these will have bipolar I or II disorder, while the other half will probably have major depressive disorder.
If both parents have bipolar disorder, the child has a 50%-75% chance of developing a mood disorder. The finding that the concordance rate for monozygotic twins is not 100% suggests that environmental or psychological factors likely play a role in causation of bipolar disorder. Certain environmental factors such as antidepressant medication, antipsychotic medication, electroconvulsive therapy, stimulants, or certain illnesses such as multiple sclerosis, brain tumor, or hyperthyroidism, can trigger mania. Mania can be triggered by giving birth, sleep deprivation, and sometimes by major stressful life events.
Symptoms of bipolar disorder
In adults, mania is usually episodic with an elevation of mood and increased energy and activity while in children, mania is commonly chronic rather than episodic. It is usually presented in mixed states with irritability, anxiety and depression. Both in adults and children, during depression there is lowering of mood and decreased energy and activity. During a mixed episode, mania and depression can both occur on the same day.
Co-morbidity of bipolar disorder
Co-morbidity is the rule, not the exception in this disorder. The most common mental disorders that co-occur with bipolar disorder are anxiety, substance abuse, and conduct disorders, as well as disorders of eating, sexual behavior, attention-deficit/hyperactivity, and impulse control. Autism spectrum disorders and Tourette's disorder, co-occur with bipolar disorder. The most common general medical co-morbidities are migraine, thyroid illness, obesity, type II diabetes, and cardiovascular diseases.
Mental disorders associated with bipolar and its diagnosis
Bipolar disorder is often associated with alcoholism, drug addiction, anorexia nervosa, bulimia nervosa, attention-deficit hyperactivity disorder, panic disorder, and social phobia. Unfortunately, there are no diagnostic laboratory tests for bipolar disorder. Thus diagnosis is arrived at by using standardized diagnostic criteria to rate the patient’s behavior. However, bipolar disorder must be distinguished from mood disorder due to a general medical condition, for example due to multiple sclerosis, stroke, hypothyroidism, or brain tumor. Bipolar disorder should also be distinguished from substance-induced mood disorder (for example due to drug abuse, antidepressant medication, or electroconvulsive therapy), and from other mood disorders such as major depressive disorder, dysthymia, bipolar disorder II, and cyclothymic disorder. It is even more important to see the difference between bipolar disorder and psychotic disorders such as schizoaffective disorder, schizophrenia, or delusional disorder. Since this disorder may be associated with hyperactivity, recklessness, impulsivity, and antisocial behavior, the diagnosis of bipolar disorder must be carefully differentiated from attention deficit hyperactivity disorder, conduct disorder, antisocial personality disorder, and borderline personality disorder.
Pathophysiology and prevalence of bipolar disorder
The pathophysiology of bipolar disorder is poorly understood, but a variety of imaging studies suggests the involvement of structural abnormalities in the amygdala, basal ganglia, and prefrontal cortex. Research is now showing that this disorder is associated with abnormal brain levels of serotonin, norepinephrine, and dopamine, which are very important substances in the brain.
Bipolar disorder affects both sexes equally in all age groups and its worldwide prevalence is approximately 3-5% and it can even present in preschoolers. There are no significant differences among racial groups in the prevalence of bipolar disorder. Moreover, the first episode may occur at any age from childhood to old age, although the average age at onset is 21. More than 90% of individuals who have a single manic episode go on to have future episodes, while untreated patients with bipolar disorder typically have 8 to 10 episodes of mania and depression in their lifetime. Often five years or more may elapse between the first and second episode. However, the episodes become more frequent and more severe thereafter. There is a significant symptom reduction between episodes, but 25% of patients continue to display mood instability or mild depression, as many as 60% of patients experience chronic interpersonal or occupational difficulties between acute episodes. Bipolar disorders may develop psychotic symptoms, while psychotic symptoms only occur during severe manic, mixed or depressive episodes. In contrast, the psychotic symptoms in schizophrenia can occur even when there is no mania or depression. The problem is, poor recovery is more common after psychosis. Manic episodes usually begin abruptly and last for between 2 weeks and 4-5 months with median duration of 4 months. Depressive episodes tend to last longer with median length about 6 months, though rarely for more than a year, except in the elderly.
Treatment and outcome of bipolar disorder
The usual treatment for bipolar disorder is lifelong therapy with a mood-stabilizer. It could be lithium, carbamazepine, or divalproex and valproic acid. These drugs work the best in combination with an antipsychotic medication. Usually treatment results in a dramatic decrease in suffering, and causes an eight-fold reduction in suicide risk. In mania, an antipsychotic medication or a benzodiazepine medication is often added to the mood-stabilizer, while in depression, an antidepressant medication or lamotrigine is often added to the mood-stabilizer.
Since antidepressant medication can trigger mania, this medication should always be combined with a mood-stabilizer or antipsychotic medication to prevent mania that is the common problem. Research has shown that the most effective treatment is a combination of supportive psychotherapy, psycho-education, and the use of a mood-stabilizer, which might be often combined with an antipsychotic medication. However, there is no research showing that any form of psychotherapy is an effective substitute for medication. Likewise there is no research showing that any health food store nutritional supplement such as vitamin or amino acid, is effective against bipolar disorders. Since a manic episode can quickly escalate and destroy a patient’s career or reputation, a therapist must be prepared to hospitalize out-of-control manic patients before they lose everything. Likewise, severely depressed, suicidal bipolar patients often require hospitalization. This is necessary to save their lives. Although the medication therapy for bipolar disorder usually must be lifelong, most bipolar patients are non-compliant and stop their medication after one year.
It is also important to point out that according to the US government’s National Institute of Mental Health there is no single cause of bipolar disorder, but rather, many factors act together to produce the illness. Probably that is why single medication cannot help these people. Modern evidence-based psychotherapies designed specifically for bipolar disorder, when used in combination with standard medication treatment, increase the time the individual stays well significantly longer than medications alone.