Practical Geriatrics: Clinically Significant Nonmajor Geriatric Depression

In current psychiatric practice and research in both elderly and nonelderly adult populations, two principal approaches define depression: depressive symptoms, and more specific depressive illnesses or disorders defined in terms of the duration, number, and type of depressive symptoms. Most nonpsychiatrists typically regard depression in terms of the first construct, whereas psychiatrists use the second construct. Most studies demonstrate that patients with depressive symptoms, even in the absence of a specific depressive disorder, experience considerable morbidity and reduced social functioning (4,5).

Subsyndromal depressive-spectrum disorders have been proposed by various investigators in their conduct of longitudinal studies of large populations of adult and geriatric patients. In a 15-year follow-up community-based cohort-study, Angst and colleagues (4) studied the longitudinal course of young adult patients with a diagnosis of major depressive disorder, dysthymia, recurrent brief depression, or minor depression. These researchers found very little stability for the specific types of depression among persons who continued to manifest depression during the follow-up period: 51 percent of patients with major depressive disorder and 44 percent of those with recurrent brief depression met criteria for another subtype of depression (4).

When stability was observed, the same subtype occurred in combination with the development of another subtype. Among patients with a single subtype, severity was greatest among those with dysthymia, whereas patients with combined subtypes had greater severity than those with a single subtype. The researchers suggested that symptom threshold and recurrence—but not the minimum duration of depressive episodes—should serve as a basis for classification (4).

Does nonmajor depression among elderly persons differ from depression among younger adults? Some similarities and differences exist in the phenomenology and disease course of depression between elderly and younger adults. Blazer and colleagues (6) identified a symptom-cluster profile unique to people older than 60 years, characterized by depressed mood, psychomotor retardation, poor concentration, constipation, and poor self-perception of health. This cluster was associated with cognitive deficits and physical illness and did not correspond to any particular DSM category.

The spectrum of geriatric depression also extends to patients with underlying medical or progressive dementing disorders who may develop depression during their illness (3). Among bereaved individuals, subsyndromal and minor depression stood between major depression and absence of depression in terms of their effect on the overall adjustment to widowhood, which supports the spectrum concept (7). Some investigators have identified clinical features of dysthymia that are clearly different among elderly persons, including late onset, comorbid medical illness, cognitive deterioration, and frequent adverse life events (8).

The nosologic status of minor depression together with the variability in diagnostic criteria contributes to the variability in prevalence estimates of these disorders. Relevant factors include differences in diagnostic systems, severity threshold, and duration of illness required for the diagnosis of various affective states or disorders. Despite these methodologic considerations, there is broad consensus on the prevalence and clinical impact of nonmajor forms of mood disorders both in the broader community and in more specialized clinical settings (6).

Studies of treatment of nonmajor depressive disorders are limited (14,15). Little is known about treatment strategies for clinically significant nonmajor depression. Most studies have focused on dysthymia and minor depression in primary care settings.

Descriptive studies have established that primary care providers use one or more of three modalities in treating depression: watchful waiting, medication, and referral to the specialty sector. In the case of watchful waiting, the most commonly used modality, it has been shown that return visits involve sympathetic listening and a show of interest, and in some cases brief "common sense" counseling.

The use of medication is virtually the only active treatment delivered by primary care providers, but the evidence of efficacy of psychopharmacologic interventions for persons with nonmajor depression is lacking. Oxman and Sengupta (14) reviewed treatment of minor depression and concluded that older persons were as responsive to treatment as younger persons. The limited evidence from randomized trials that have included a control condition suggests that antidepressants and counseling have some benefit and should be attempted. However, the placebo responses were high in the few controlled studies that have been conducted, and such nonspecific therapeutic factors as an attentive physician may be particularly beneficial.

Both similarities and differences exist in the clinical manifestations of clinically significant depressive disorders. There is an emerging consensus from epidemiologic and longitudinal studies that supports the idea of a continuum of depressive disorders, ranging from the very mild "subthreshold" depression to major unipolar and bipolar disorders. All forms of clinically significant depression are associated with considerable economic and psychosocial consequences. Current approaches to studying affective illness that adhere to traditional nosologic categories may not be adequate for the next generation of research into the biologic and psychosocial correlates of this group of disorders. We propose clinical criteria for the diagnosis of clinically significant nonmajor depression among elderly persons (see box). These criteria are consistent with operational definitions of minor depression used in other clinical studies but are broader in clinical and methodologic scope.

This work was supported in part by a Young Investigator Award from the National Alliance for Research on Schizophrenia and Depression and by grant K23-MH-01948 to Dr. Lavretsky and grants MH-55115, MH-61567, and KO2-MH-02043 to Dr. Kumar from the National Institutes of Health.

The authors are affiliated with the department of psychiatry and biobehavioral sciences of the University of California, Los Angeles, School of Medicine. Send correspondence to Dr. Lavretsky at UCLA Neuropsychiatric Institute, Room 37-425, 760 Westwood Plaza, Los Angeles, California 90095 (e-mail, [email protected]). Marion Z. Goldstein, M.D., is editor of this column.