Few disorders throughout history have been described with such consistency as mood disorders. Symptoms that characterize the disorders can be found in medical literature throughout the centuries from the ancient Greeks to the present era. As early as the 4th and 5th centuries BC, the term melancholia was used by ancient Greeks to describe the dark mood of depression. Hippocrates used the term melancholia to describe depression and mania to describe mental disturbances in clients. During the 2nd century AD, Arteaeus of Cappadocia described cyclothymia as a form of mental disease with alternating periods of depression and mania. For centuries, melancholia and cyclothymia were regarded to be separate disease entities rather than diverse expressions of mood disorders. By 1880, four categories of mood disorders existed: mania, melancholia, monomania, and dipsomania. In 1882, a German psychiatrist, Karl Kahlbaum described melancholia and mania as a continuum of the same illness. In 1899, Emil Kraepelin, another psychiatrist, reinforced Kahlbaum’s theory about the continuum of depression. Kraepelin introduced the category of manic-depressive psychosis, citing most of the criteria now used to establish the diagnosis of bipolar I disorder. He also introduced the category of involutional melancholia, now viewed as a mood disorder that occurs in late adulthood (Emental-health.com, 2005a, 2005b; Sadock & Sadock, 2003).

In the past, causes of a mood disorder were classified as genetic, biochemical, and environmental. In addition, several medical illnesses are highly correlated with mood disorders. Moreover, individuals of any age may experience changes in mood or affect as an adverse effect of medication. However, older adults are more likely than younger adults to experience medication-related mood disorders. Risk factors for the development of mood disorders have been identified as clinical practice guidelines for primary care practitioners. These are highlighted in Box 21-1. In addition, several theories about mood disorders have been postulated.

The clinical symptoms of depressive disorders, one of the two major types of mood disorders, have been categorized in many ways. One method is by placing depressive behaviors on a continuum from mild or transitory depression to severe depression. Mild depression is exhibited by affective symptoms of sadness or “the blues”—an appropriate response to stress. The person who experiences such depression may be less responsive to the environment and may complain of physical discomfort. However, the person usually recovers within a short period. For example, a person may become disappointed when told that he or she was not chosen as a representative to a conference that the person hoped to attend. During this time, the person may be unable to concentrate, may communicate less with coworkers, may appear less productive than normal, and may isolate him- or herself at work and at home.

Clinical symptoms of moderate depression (dysthymia) are less severe than those experienced in a major depressive disorder and do not include psychotic features; e.g., individuals with dysthymia usually complain that they have always been depressed. They verbalize feelings of guilt, inadequacy, and irritability. They exhibit a lack of interest and lack of productivity. Persons with severe depression exhibit psychotic symptoms such as delusions and hallucinations.

Major depressive disorders are referred to as endogenous depression when the depressed mood appears to develop from within a client, and no apparent cause or external precipitating factor is identified. Depression caused by a biochemical imbalance is such an example.

The DSM-IV-TR categorizes depressive disorders as major depressive disorder; dysthymic disorder; and depressive disorder, not otherwise specified (NOS). The DSM-IV-TR diagnostic criteria for prepubertal, adolescent, and adult depression are identical. Information regarding childhood and adolescent depression is provided in Chapter 29. Late-life depression is discussed in Chapter 30.

Various descriptive terms are used to describe the labile affect or mood changes of clients with the diagnosis of bipolar disorder. These terms include:

These changes may be placed on a continuum, from mild to severe, the same as those of depressive behaviors.

The client with mania generally exhibits hyperactivity, agitation, irritability, and accelerated thinking and speaking. Behaviors may include pathological gambling, a tendency to disrobe in public places, wearing excessive attire and jewelry of bright colors in unusual combinations, and inattention to detail (Figure 21-2). The client may be preoccupied with religious, sexual, financial, political, or persecutory thoughts that can develop into complex delusional systems. Flight of ideas, as well as other psychotic symptoms discussed in Chapter 9, may persist (Sadock & Sadock, 2003; Shahrokh & Hales, 2003).

BPD is generally underdiagnosed because of under-recognition of manic and hypomanic episodes. The complex nature of BPD makes an accurate differential
diagnosis a challenge, even for experienced clinicians. Although many clients present to a health care provider within 1 year of symptom onset, there is usually a 5- to 10-year delay from symptom onset to formal diagnosis. Many clients report that they have not been correctly diagnosed until they were seen by three or more health care professionals (St. John, 2005).

As noted earlier, BPD affects approximately 2.3 million American adults (or about 1.2%) age 18 years and older in a given year. Men and women are equally likely to develop BPD. The average age of onset is in the early twenties (NIMH, 2005). The clinical presentation of BPD in children and adolescents is often different from that seen in adults. Moods in children and adolescents tend to be more irritable than euphoric. In addition, adolescents often have greater difficulty with mood liability, explosive outbursts of anger followed by remorse, and prolonged emotional response to stimuli. They often perform poorly academically and exhibit abrupt switches between good and bad behavior. Mania in adolescents is commonly misdiagnosed as antisocial personality disorder (see Chapter 24) or schizophrenia (see Chapter 22). Although BPD is less common with increasing age, the first episode can occur in older adults. The estimated prevalence of mania in elders is 5% to 19%. The mortality rate for untreated BPD is higher than for most types of heart disease and some types of cancer (St. John, 2005).

The category of BPD includes bipolar I disorder; bipolar II disorder; cyclothymic disorder; and BPD, NOS. BPD, NOS, is used to code disorders with features of BPD when these features do not meet the criteria for any specific BPD. Bipolar I, bipolar II, and cyclothymic disorders are discussed in the following sections.