Depression
Most patients with depression present to primary care physicians, often complaining of somatic symptoms. The frequency, treatability, and potentially serious consequences of depression make its diagnosis and management high priorities for the primary care physician. Unfortunately, the diagnosis is not always evident because the symptoms may masquerade as a variety of psychiatric or somatic conditions. Moreover, the stigma of psychiatric diagnosis can impede recognition of depressive illness by both patients and physicians.
The purported mechanisms of depression include psychodynamic, cognitive, genetic, neuroendocrine, and neurotransmitter determinants. Depression most likely represents a complex combination of these elements. Genetic factors and/or early childhood experiences may render persons more susceptible to depression. Neurotransmitter and neurohumoral elements probably serve as important effector pathways for development of symptoms.
Psychodynamic origins are believed to involve difficulties with formation and maintenance of self-esteem, which may occur from having hypercritical parents or being abused. In addition, growing up in an emotionally unresponsive environment may compromise learning ways to effectively cope with situational stresses. Suffering loss or failure as an adult is likely to be difficult, poorly responded to, and capable of reawakening prior painful feelings of inadequacy and worthlessness that lead to depression. Rigid dysfunctional defenses may be erected in an attempt to minimize the chances of loss or failure.
The cognitive perspective views depression as the consequence rather than as the origin of negative or distorted thinking. Subscribing to inflexible rules of conduct and unattainable goals can be a setup for failure and loss of self-esteem. Setbacks are viewed as a reflection of one’s unworthiness and inadequacy.
Genetic determinants have been discovered from studies of twins, chromosomes, and pedigrees. In some pedigrees, there appears to be a dominant gene with incomplete penetrance. A family history of affective disease is commonly elicited. Major depression is up to three times more common among firstdegree relatives of people with the disorder than in the general population.
Neurotransmitter basis of depression began with the finding that reserpine could induce depression and monoamine oxidase inhibitors could reverse it. This led to the identification of altered neurotransmitter metabolism as an important biochemical concomitant of depression and to the discovery of new antidepressant drugs, each increasing the availability of a major central neurotransmitter (e.g., norepinephrine, serotonin, or acetylcholine), usually by selective inhibition of reuptake.
Neuroendocrine hypotheses derive from the observation that most neurovegetative manifestations of depression (changes in appetite, libido, diurnal rhythms) involve hypothalamic functions. In addition, links between neurotransmitter release and neurohormone activity have been identified. Corticotropic releasing hormone is believed to play an important role, resulting in hypercortisolism. Early morning awakening, reflecting an abnormal advance in circadian rhythm, may be one consequence.
Depression’s clinical presentation includes a host of psychological and bodily complaints.
Psychological Manifestations. Sadness is a very common symptom. Irritability, discouragement, loss of interest, worry, frustration, and decreased libido comprise the major dysphoric manifestations and may occur in the absence of overt sadness. Some patients become preoccupied with physical complaints, such as pain or bowel dysfunction. Others exhibit changes in memory, concentration, or self-image. Diurnal mood variation is characteristic, with symptoms often worse in the morning and improving as the day progresses.
Depressed affect can be subtle, at times only noticed when sadness ensues from talking with the patient. As depression worsens, psychomotor abnormalities may appear. Although psychomotor retardation, with slowed speech and a long latency before the patient answers questions, has been thought of as the classic presentation of depression, in fact, anxiety is the much more common symptom. Nearly three fourths of patients with a depressive disorder have worry, psychic anxiety, or somatic anxiety as one of their presenting symptoms.
Somatic Manifestations. Distinctive neurovegetative symptoms include disturbed sleep (most commonly early morning awakening), lack of energy, and decreased appetite Neurovegetative symptoms are predictive of responsiveness to psychopharmacologic intervention. In what is termed an atypical depression, patients may exhibit increased sleep and increased appetite (hypersomnolence and hyperphagia).
Major Depression (Unipolar Depression). This is the DSM-IV term for serious depression that is accompanied by neurovegetative symptoms. Lifetime risk of developing a major depression is estimated to be one in four for women and one in eight for men. Dysphoric mood typically dominates the clinical picture and is persistent. Four or more of the major neurovegetative symptoms dominate the clinical picture and are present for a minimum of 2 weeks, including appetite disturbance, sleep disturbance, psychomotor retardation or agitation, anhedonia, loss of energy, feelings of worthlessness or guilt, decreased concentration, and suicidal thoughts.
Onset is variable. Symptoms usually develop over weeks to months, but they may develop suddenly. Situational factors surrounding the onset of the illness have no bearing on the diagnosis. Historically, distinctions were made between endogenous and reactive depression, but an identifiable precipitant is no longer considered pertinent with respect to diagnosis. Frequency of episodes appears to increase with age. At least half of patients have recurrent episodes. A family history of a major affective disorder (major depression or bipolar disorder) is common. The relationship between alcoholism and depression remains controversial.
Major Depression with Psychotic Features. A subclassification of major depression, this disorder has the additional features of delusions, hallucinations, bizarre behavior, or disorganized thinking.
Major Depression in the Elderly. In the elderly, depression can mimic dementia. The patient may appear withdrawn, unkempt, inattentive, or even confused. The condition may be due to depression alone or to a combination of depression and dementia.
Bipolar Disorder–Depressed Phase. The presentation of a depressive episode in a bipolar (manic-depressive) patient is identical to that of major depression, except there is a history of prior manic or hypomanic episodes. Mania is manifested by periods of elation or expansive mood, increased energy, decreased need for sleep, inflated self-esteem, and overinvolvement in activities, accompanied by a decreased concern for the consequences. Its diagnosis requires adequate severity to substantially impair level of functioning. If the hallmark symptoms of mania exist, but the patient shows no decrement in functioning, the patient is described as hypomanic.
Distinguishing between unipolar and bipolar depressions is very important in determining treatment (see below).
Dysthymic Disorder. This category denotes a chronic low-grade depression, characterized by pervasive dysphoric mood for at least 2 years. Some complain of life-long feelings of depression. Symptoms are less severe than those of major depression and neurovegetative symptoms are fewer. Depression appears as an integral part of personality or their character (hence the older term characterologic depression). Such patients can be frustrating to treat because of chronic dysphoria, self-pity, and development of irrational patterns of negative thinking (e.g., “things always go wrong for me”). The physician typically develops feelings of helplessness and may unconsciously communicate a wish that the patient would go away.
Typically, onset is in adolescence or early adult life and accompanied by other symptoms of a personality disorder, such as a history of difficulty with interpersonal relationships, manipulativeness, feelings of emptiness, and lack of an identity. A subpopulation of dysthymic patients seems to have an attenuated chronic form of major depression with onset later in life after a period of good functioning. Neurovegetative symptoms may be more prominent.
Dysthymia and major depression can coexist in a given patient (so-called “double depression”), when a major depressive episode evolves in the context of preexisting dysthymia. However, incomplete recovery from a major depression should be described as major depression in partial remission rather than dysthymia.
Cyclothymic Disorder. This state resembles bipolar illness, but the mood swings are less severe. These patients have a chronic mood disturbance characterized by periods of depression alternating with periods of elevated mood. Neither are of sufficient severity or duration to meet the criteria for major depressive or manic episodes. Interspersed may be periods of normal mood lasting as long as several months.
Seasonal Affective Disorder. This depressive variant is distinguished by its seasonal pattern, characteristically beginning in the fall and ending about 5 months later. It has been linked to lack of light exposure and is more common in northern latitudes. Alterations in serotonin activity have also been noted. As in other forms of depression, sadness is the dominant affect, and fatigue and decreased libido are common. Atypical features include tendencies to overeat and oversleep. In the United States, women are more commonly affected than men (ratio, 3:1). Age of onset is typically in the 20s.
Adjustment Disorder with Depressed Mood. This occurs after a significant life stress. Patients usually present with depressed mood associated with feelings of hopelessness, helplessness, worthlessness, and anxiety. Their thoughts are often dominated by the problems that precipitated the episode. Sleep and appetite disturbances are common but are less severe and less persistent than in major depression. The condition is usually self-limited, lasting less than 6 months and improving when the stress is removed or the individual evolves a more adaptive coping mechanism. It is important to note that any patient with symptoms severe enough to meet the criteria for major depression (described above) should receive that diagnosis regardless of the history of a precipitant. The message that the primary care physician should gather from this chapter is that evaluating the depressive symptoms, regardless of a suspected precipitant, is crucial, and possibly life saving, in initiating antidepressant treatment.