Mood disorders, previously called affective disorders, include a number of psychiatric diagnoses where the major symptom is a disturbance of mood. Most individuals experience a wide range of emotional states from sadness and grief to elation. Even the most extreme mood states do not usually interfere with daily functioning for a prolonged period of time. In contrast, a mood disorder occurs when a persistent state of sad, depressed mood, or elevated, irritable mood interferes with daily life. Depressive disorders and bipolar disorders are the two main categories of mood disorders.
Major depressive disorder (also known as major depression) and dysthymic disorder (or dysthymia) make up the core depressive disorders. Major depressive disorder is the most common of the depressive mood disorders with a lifetime prevalence of 5-12% in men and 10-25% in women. The prevalence of major depression is twice as high in women as it is in men in nearly every country in which epidemiological studies have been conducted. The exception to this finding is among the Orthodox Jewish community across several countries. Cultural differences and a lack of substance use, particularly alcohol, may account for these findings. One theory about the high rate of depressive illness in women compared to men is that there are significant hormonal changes throughout the life span, particularly just after menarche, childbirth, and menopause. Gender roles may also play a part in the incidence of depression in women, especially for women with very young children trying to balance work and home.
The diagnosis of major depression depends upon the presence of a major depressive episode, which is characterized by an overwhelming low mood and/or a loss of interest or pleasure in most activities. An episode is a distinct period of time, lasting at least 2 weeks, that is marked by a significant decline in one’s ability to function in a usual manner. The persistent low mood is accompanied by one or more of the following symptoms: loss of appetite (or increased appetite) usually accompanied by weight loss or gain, difficulty sleeping or excessive sleeping, feelings of restlessness or being slowed down, fatigue, loss of energy, and inappropriate feelings of guilt, poor memory or difficulty concentrating, and thoughts of suicide or death. The presence of a manic or hypomanic episode precludes the diagnosis of a depressive disorder.
The first onset of major depression occurs between the ages of 20 and 50 for 50% of those diagnosed with the disorder; however, the mean age of onset is 40 years of age. Depression also occurs in approximately 2% of children and 4-8% of adolescents. Children may present with primary irritability as well as depressed mood. The distress is commonly identified due to school failure, truancy, drug and alcohol use, persistent irritability, violence, or withdrawal from peers and activities. Major depression occurs in 15% of the elderly (>65 years) population, which is more than 60% female. Onset of major depression at this age is not related to the aging process; rather, it is associated with bereavement due to the loss of a spouse or the stress of a chronic medical condition. Depressive symptoms in the elderly commonly include low mood, low selfesteem, worthlessness, and guilt. Cognitive impairment is not uncommon and must be distinguished from dementia related to aging.
The average duration of an untreated major depressive episode is 6-13 months. When treated, the course may be as short as 3 months, typically resolving by 6 months. Often patients discontinue treatment once they are feeling better. This leads to a return of the symptoms if discontinuation occurs in the first 3 months of treatment. Medication should be tapered gradually to avoid side effects and relapse. Over time, the duration and number of episodes can increase.
Depressive episodes are experienced in several ways. Symptom severity in a depressive episode varies from mild to severe. The number of symptoms experienced in a depressive episode varies from as low as 5 to as many as 10 or more. The depressive episodes may also be recurrent, seasonal (Seasonal Affective Disorder), or occurring within 1-6 months after childbirth (postpartum onset or Postpartum Depression). The depressive episode may be further defined by specific coinciding symptoms, namely, psychotic symptoms (delusions, hallucinations), catatonic (extreme disturbance of mobility), melancholic (mood worse in the morning, low reactivity to pleasurable stimuli, significant slowing or agitation, and inappropriate guilt), or atypical features (mood brightens to positive events, excessive sleeping, increased appetite, or weight gain).
Unlike major depressive disorder, which is characterized by one or more depressive episodes in a distinct period of time, Dysthymia is a chronic, persistent depressed mood for at least 2 years. Individuals with dysthymia often report that they have always been depressed or that they have never been as happy as others in their lives. Feelings of inadequacy and persistent irritability, pessimism, withdrawal from social events, and low activity level are common in Dysthymic Disorder. Symptoms of poor appetite or overeating, fatigue, sleep disturbance, low self-esteem, and poor concentration are common but are not severe enough to impair daily functioning. Children and adolescents with dysthymic disorder are usually irritable and pessimistic, have a low self-esteem, poor social skills, and declining school performance. After the initial 2-year period of depressed mood, major depressive episodes may occur in addition to the chronic low mood and has been called “Double Depression.” Dysthymia has a lifetime prevalence of 6%. The disorder typically develops early, with most experiencing the onset by 21 years of age. In children, the number of girls affected is equal to that of boys. However, in adulthood, the incidence in women is 2-3 times that of men.
Other depressive mood disorders have been described in the research and clinical literature. Minor depressive disorder has similar episodic symptoms to major depression but with lower symptom severity. Recurrent Brief Depressive Disorder is characterized by recurring depressive episodes meeting criteria for major depression but for durations of less than 2 weeks at one time. Premenstrual Dysphoric Disorder is a diagnosis currently under research investigation to determine its validity as a distinct disorder. The disorder is distinguished by abnormal mood and behavior in addition to physical symptoms, such as headache, breast tenderness, and swelling during the week between ovulation and the onset of menstruation. The symptoms are severe enough to interfere with daily functioning and remit once menses occurs.
Bipolar disorders are chronic, often devastating disorders that are characterized by manic or hypomanic episodes. A manic episode is a distinct period of at least 1 week marked by an abnormal elevation of mood that causes a significant loss of daily functioning. A manic episode may initially be a state of euphoria or a period of persistent irritability and low frustration tolerance, which often leads to loss of control. Other concurrent symptoms generally include: exaggerated self-esteem, talkativeness or pressured speech, racing thoughts, a decreased need for sleep, poor attention, and an overindulgence in pleasurable activities (drinking, spending money, sex). An individual in a manic episode may present with delusions, perceptual disturbances, and gross psychotic symptoms. A hypomanic episode is similar symptomatically to a manic episode except that it does not cause significant impairment in social or occupational functioning. There are no psychotic symptoms during a hypomanic episode. A bipolar mood episode may also be mixed in that both depressive and manic symptoms are present simultaneously.
There are three main classifications of bipolar disorders: Bipolar I disorder, Bipolar II disorder, and Cyclothymic disorder. Bipolar I disorder is characterized by at least one manic episode with or without a current or past major depressive episode. Bipolar II disorder is present when there is a current or past major depressive episode and a current or past history of at least one hypomanic episode with no history of a manic episode. The current functioning of the individual is significantly impaired. Psychotic features may be present in bipolar II disorder. The depressive episodes of both bipolar I and II disorders may occur seasonally. The mood episodes of the disorders may be rapid cycling if at least four episodes are identified in a 12-month period. Similar to the depressive disorders, bipolar disorders are also described in terms of specific features of catatonia, melancholia, atypical, or with postpartum onset.
Bipolar disorders have a lifetime prevalence of 1.3—1.6%. Although the onset is usually between 15 and 24 years of age, there is typically a 5to 10-year delay in seeking treatment. The onset of bipolar disorder may also occur in childhood with symptoms more consistently presenting as irritability and hyperactivity. Early onset of bipolar illness typically follows an initial depressive episode and is frequently a more severe illness than when onset occurs in adulthood. Women and men are affected equally in most bipolar disorders. However, women have a higher incidence than men of rapid cycling and mixed episodes.
Cyclothymic disorder (cyclothymia) is a mild form of bipolar II disorder. It is a chronic disorder with at least 2 years of recurring episodes of hypomania and mild depression with remissions lasting less than 2 months at one time. Cyclothymic disorder is often comorbid with borderline personality disorder. The onset is usually between the ages of 15 and 25 with a lifetime prevalence of 1%. Cyclothymia affects women more than men.
OTHER MOOD DISORDERS
Schizoaffective disorder is classified as a psychotic disorder rather than a mood disorder. However, a depressive, manic, or mixed episode occurring with two or more of the characteristic symptoms of schizophrenia would be considered schizoaffective disorder. These characteristic symptoms are delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, flat affect, and lack of motivation. These symptoms are not usually as severe as when experienced in schizophrenia.
CAUSES OF MOOD DISORDERS
The causes of mood disorders are not fully understood. However, there are strong indications that mood disorders are influenced by the combination of biological, genetic, and psychosocial factors. The biological factors include altered levels of neurotransmitters in the brain, particularly serotonin, norepinephrine, and dopamine. Other significant biological factors include alterations in neuroendocrine systems (stress system), thyroid hormones, circadian rhythm disturbances, and neuroanatomical changes. Family and twin studies have shown that genetics plays a large role in mood disorders, particularly in bipolar I disorder. The particular alterations in these systems may vary depending on the type or subtype of the mood disorder. Psychosocial factors, such as high life stress, multiple losses, poor social support, and trauma, can influence the development of a mood disorder, particularly the depressive disorders.
COMORBIDITY AND MORTALITY
Mood disorders coexist with a variety of other disorders. Depressive disorders are highly comorbid with anxiety disorders. Alcohol and substance abuse/dependence are common in those afflicted with either a depressive or bipolar mood disorder. Individuals with a medical condition (especially one that is chronic) are more likely to have depressive mood disorders. In some cases, the mood disorder may be caused by substance abuse, prescription and nonprescription medications, or a medical condition. A careful, thorough medical and psychiatric evaluation is needed to rule out the causative agent to ensure proper treatment. Mood disorders brought on by medication or a general medical condition are secondary mood disorders that usually resolve once the causative agent is removed or the condition treated.
The greatest risk with mood disorders is the occurrence of suicide with a depressive episode, especially at the onset or end of an episode. It is estimated that 400 of every 100,000 male patients and 180 of every 100,000 female patients commit suicide. Substance abuse and social isolation increases the risk of suicide in mood disorder patients.
Treatment of mood disorders depends upon the specific symptoms and severity of the illness. Those with severe symptoms, psychosis, or suicidal thoughts or attempts may require hospitalization to prevent self-harm. For most individuals with mood disorders, outpatient therapy in conjunction with medication is the treatment of choice. Psychotherapies are often very helpful for the psychosocial and cognitive aspects of mood disorders. The type of therapy that is best suited for the disorder depends upon the type of disorder, symptom severity and presentation, and individual preference. The therapies include interpersonal therapy, cognitive-behavioral therapy, psychoanalysis, and family therapy.
Medication treatment is generally indicated for major depressive and manic episodes and can have a therapeutic effect in about 2-6 weeks. The choices for medication treatment for depressive episodes include tricyclic antidepressants, such as amitriptyline (Elavil and others) and clomipramine (Anafranil and others), selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine (Prozac) and sertraline (Zoloft), and other novel depressants. Monoamine oxidase inhibitors (MAOIs) such as phenelzine (Nardil) and tranylcypromine (Parnate) are generally used to treat atypical or refractory depression. There is a reluctance to use the MAOIs due to the potential for a hypertensive crisis if the patient does not eliminate tyrosine from their diet. High tyrosine levels are found in many sharp cheeses, cured meats, and fish. The treatment of major depression or bipolar disorder with psychotic features requires additional treatment with antipsychotic medication. The main treatment for bipolar I disorder is mood stabilization with lithium (Lithobid and others), valproic acid (Depakote and others), or lamotrigine (Lamictal).
Atypical antipsychotic medications such as olanzapine (Zyprexa) and risperidone (Risperdal) are also gaining popularity in the treatment of bipolar illness. Obtaining long-term mood stability with medication is reportedly related to a reduction in suicide rates in individuals with bipolar and schizoaffective disorder. Treatment of bipolar II disorder is more complicated due to the frequent depressive episodes which may require medications that induce a hypomanic episode.
Alternative therapies include light therapy, sleep deprivation, and electroconvulsive therapy (ECT). In circumstances of a depressive episode or manic episode with medication failure, intolerance to medications, or severe psychotic or suicidal symptoms, electroconvulsive therapy is the treatment of choice. Electroconvulsive therapy is a generally safe, fast, and effective method of treatment. Electroconvulsive therapy involves the induction of a generalized seizure by sending pulses of electrical current through the scalp into the brain. Electroconvulsive therapy is not contraindicated in pregnancy, and has been used for the same indications without apparent harm to the fetus.
Drug treatment in women requires special attention to the possibility of pregnancy and lactation while being treated with the medication. Physicians are sometimes reluctant to prescribe psychotropic medications during pregnancy due to the potential adverse affects on the fetus. However, recent data support the use of some medications during pregnancy, especially when the risk of suicide or self-harm is high. There is also sufficient evidence to suggest that fetal exposure to maternal mood disorders may also impact fetal behavior and development. Antidepressant medications, particularly the selective serotonin reuptake inhibitors and tricyclic medications, have been found to be relatively safe during pregnancy between 9 and 36 weeks gestational age. It is recommended that the dosage be tapered in the last month of pregnancy to decrease the risk of neonatal withdrawal. Selective serotonin reuptake inhibitors are the current firstline choice of clinicians for treatment during pregnancy due to relatively fewer side effects and low risk to the fetus. The use of mood stabilizers such as lithium during pregnancy is associated with greater risk to the fetus; however, the benefits of the medication may outweigh the risks.