Early detection of depression in young and elderly people

Introduction

Effective treatment of depression requires early detection. Depression can be difficult to identify among subgroups of patients with co-morbid medical illnesses, substance abuse disorders, mental retardation, brain injury, and dementia, or those who are at either end of the age spectrum. This article addresses risk factors and unique aspects of presentation in the young and the old. 

Detecting depression in young people

Prevalence and risk factors

While major depressive disorder (MDD) remains relatively uncommon in preadolescents (Table 1), the prevalence rises dramatically with the onset of adolescence.[1] During the past 30 years, the rate of depression has risen in successive age cohorts. The morbid risk by the end of the teen years is now 20%.[2] However, half of major depressive episodes in community populations of teens will have spontaneously resolved by 2 months.[1] Nevertheless, more brief depressions may herald future, more severe episodes. Recurrence rates for depression in young people are even higher than those in adults, with at least 50% recurrence within the next 2 years and 75% within 5 years.

Table 2 shows established risk factors for depression. The most powerful predictive risk factor is a first-degree relative with depression, increasing the morbid risk by the end of the teen years to 50% from 20% in the control population.[2] Being raised by a depressed parent compounds this risk. Therefore, primary care physicians can readily identify their young patients at highest risk—offspring of depressed parents. Conversely, the detection of depression in a preadolescent child is a strong marker for the recent or concurrent presence of depression in one or both of the parents. 

Early onset depression may be more severe and genetically determined, and thus more similar to treatment-resistant adult cases, and is more likely to lead to bipolar disorder. Early onset cases also tend to have other risk factors (Table 2) that may promote a depressogenic cognitive and behavioral coping style. Early losses or trauma may also result in persistent biological changes that predispose to depression. Furthermore, when a young person becomes depressed, life quickly becomes complicated by negative events that perpetuate the illness. These include school failure, loss of friendships, dropping out of activities such as sports and artistic endeavors, and negative reactions from parents and teachers who are frustrated by the child’s low motivation and output. Even after recovery, deficits in academics and social relationships persist; there appears to be a developmental cost of having a depressive episode in the childhood or teen years. 

Presentation and diagnosis

There are age-related differences in presentation.[3] Major depression in preadolescents is accompanied by symptoms of separation anxiety in 50% of cases, which may obscure the symptoms of depression. Initial and terminal insomnia, as well as reduced eating and weight loss or failure to gain appropriately, are common. In contrast, lethargy, hypersomnia, and increased appetite and eating are more characteristic among adolescents. At all ages, decline in academic functioning, social withdrawal, and irritability are seen. Marked irritability may result in angry or even aggressive outbursts that obscure the underlying depression. Adolescents may show temporary cheering-up in the presence of peers, and in all young people, mood may be more reactive than in adults with depression. The decline in function, however, clearly indicates the severity of the condition.

Physical concerns such as fatigue, abdominal pain, headaches, or sleep disturbance are commonly the reason that depressed children and adolescents are initially brought to the family physician, so screening questions for depression should be asked in these situations. While several scales are available, screening questions based on DSM-IV criteria are just as effective in primary care (Table 3). The family physician should look for a change in function, such as decline in school grades and/or social withdrawal. The best diagnosis is obtained by combining information from both child and parents, as parents accurately report behavioral change while children report their subjective emotional state.

Many children will have trouble identifying their mood state and may focus on physical symptoms or angrily blame others rather than express the guilt and self-blame more typical of an adult patient. Adolescents are better at identifying depressed mood. However, in assessing teens, it is important to determine that sufficient, persistent symptoms are present to meet DSM-IV criteria, as on any given day, 40% of 14-year-olds will report that they are unhappy.

The two primary psychiatric conditions likely to produce overlapping symptoms are dysthymia (chronic minor depression) and anxiety disorders. In dysthymia, the psychological symptoms of depression are present for a least a year, at least half the time, most days, while dramatic changes in neurovegetative and global functioning are absent. Chronic anxiety also produces a state of pessimism. In adolescents, marijuana abuse and dependence can both complicate and mimic depression. Other substance abuse such as alcohol abuse and dependence, or abuse of stimulants such as methamphetamine, will be challenging to distinguish from primary depression. 

In children and adolescents with depression, contributing medical conditions should be considered. Depression commonly occurs after influenza or infectious mononucleosis in teens. Poorly controlled asthma and allergies may produce physical fatigue, irritability, and disrupted sleep. Iron deficiency may produce subtle cognitive dysfunction and fatigue; less commonly, B12 deficiency is seen in vegans or those with a family history of pernicious anemia. In obese children, diabetes type II should be considered. Hence, a medical history, physical examination, and basic laboratory tests (screening for hypothyroidism and anemia) are highly recommended in children and adolescents presenting with depressive symptoms, as they are with the elderly. 

Detecting depression in the elderly

Prevalence and morbidity

Depression occurs commonly in the aging population (Table 1). Its frequency depends on the setting, with estimates rising to 10% to 12% in inpatient and long-term care settings. Symptoms can persist for up to 3 years or more if left untreated.[4]

The mortality rates of untreated depression in the elderly are high, attributable to both increased rates of completed suicide as well as increased mortality from cardiovascular and other diseases. The rate of completed suicide is twice that of younger people, for example, 26 per 100 000 among 80- to 84-year-olds compared with 12 per 100 000 in the general population.[5] A 75% increase in cardiovascular death rate has been estimated for depressed compared with non-depressed elderly.[6]

Morbidity from major depression is a significant concern in the elderly, both because of diminished function from the depression itself as well as from exacerbation of other medical symptoms and conditions. Increased use of medical services, with a 50% increase in outpatient costs, has been noted among elderly depressed patients.[7] Recovery from other medical illnesses is also delayed by concomitant depression. For example, the post-stroke depression literature indicates that untreated post-stroke depression is associated with prolonged hospital stays and lesser degrees of neurological and functional recovery.[8]

Presentation and diagnosis

Major depression may present more subtly in the elderly, with patients frequently not endorsing low or depressed mood as the primary complaint, even if asked directly. Rather, patients may complain of feeling unwell in a nonspecific way, or they may complain of specific physical symptoms, particularly abdominal pain, indigestion, and constipation. Other somatic symptoms may include generalized aches and pains, headaches, fatigue, low energy, and just feeling sick. An overemphasis on the physical complaints may lead physicians to overlook the underlying depression. Predominant somatic complaints, particularly when investigations fail to reveal an organic cause, should be regarded as a cause for suspicion of depression. 

Stereotypical impressions of the elderly may cause the clinician to miss important symptoms such as irritability, which can overshadow low mood as the primary depressive mood equivalent, and reduction in activity level. These symptoms can be easily overlooked, particularly among patients who have significant cognitive or physical limitations. The early stages of depression are often not recognized in older patients, so they may present at a more advanced stage, for example, when they have stopped eating (which may or may not be an expression of suicidal intent). Older depressed patients are also more likely to present with psychotic ideation, with typical nihilistic and negativistic delusions including themes of poverty and poor health. Poor self-esteem and themes of guilt are less common. 

Both active and passive suicidal ideation is common among elderly patients and may be difficult to detect. A high index of suspicion for suicidal risk is important, especially for recently bereaved, isolated men who are in physical pain and are drinking.[9]

Grief is a common experience among the elderly as the likelihood of multiple losses (of relationships, independence, health, comforts, activities) is a function of advancing age. It may be difficult to differentiate bereavement from major depression, and the two may co-exist, but some features make major depression more likely (Table 4). 

Conclusions

In both the very young and very old, somatic symptoms, irritability, and decline in function may be the main clues to the presence of a depressive disorder. In both age groups, collateral information from family members may be essential to making the diagnosis. The young and old share particular risk factors of medical illnesses, social isolation, and losses. Treatment also requires a combination of psychosocial rehabilitation and systematic medical interventions. Both the young and old are sensitive to medication side effects, but require the same assertive treatment shown to be effective in adult patients. Greater caution and patience is required in titrating the antidepressant doses into the therapeutic range for maximal therapeutic benefit.

Competing interests

Dr Garland received funding from Pfizer for an acute phase pharmacological study of childhood depression in 2000–2001. 

Table 1. Six-month community prevalence rates for major depressive disorder, by age.[1,4,10]

Table 2. Risk factors for depression in children and adolescents.

Table 3. Symptom criteria for major depressive disorder, using SIGECAPS mnemonic.

Table 4. Features that help distinguish between bereavement and a major depressive episode.