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Mood disorders affect the way that an individual feels. They may involve depression or manic episodes. Both depressive and manic episodes can change the way an individual thinks and behaves and the way the body functions.
Individuals with mood disorders suffer significant distress or impairment in social, occupational, educational or other important areas of functioning.
In an episode of depression, individuals may feel worthless, sad and empty to the extent that these feelings impair effective functioning. They may also lose interest in their usual activities, experience a change in appetite, suffer from disturbed sleep or have decreased energy.
Individuals in a manic episode are overly energetic and may do things that are out of character, such as spending very freely and acquiring debt, breaking the law or showing lack of judgement in sexual behaviour. These symptoms are severe and last for weeks or months, interfering with relationships, social life, education and work. Some individuals may appear to function normally, but this requires more and more effort as the illness progresses.
Children with depression may not have the same symptoms as adults. They may be irritable rather than depressed and have more anxiety, temper-tantrum and behavioural problems. The symptoms of attention deficit disorder, major depressive disorder and bipolar disorder may be very similar. Likewise, older adults may experience depression differently than younger people. It is more often expressed by anxiety, agitation and complaints of physical and memory disorders.
Major depressive disorder is characterized by one or more major depressive episodes (at least two weeks of depressed mood and/or loss of interest in usual activities accompanied by at least four additional symptoms of depression).1
Bipolar disorder is characterized by at least one manic or mixed episode (mania and depression) with or without a history of major depression.2 Bipolar 1 disorder includes any manic episode, with or without depressive episodes. Bipolar 2 is characterized by major depressive episodes and less severe forms of mania (hypomanic episodes).
Dysthymic disorder is essentially a chronically depressed mood that occurs for most of the day for more days than not over a period of at least two years,3 without long, symptom-free periods. Symptom-free periods last no longer than two months. Adults with the disorder complain of feeling sad or depressed, while children may feel irritable. The required minimum duration of symptoms for diagnosis in children is one year.
Perinatal depression, or depression surrounding the childbirth period, may be experienced by both pregnant women and new mothers.
Mood disorders are one of the most common mental illnesses in the general population. According to Statistics Canada's 2002 Mental Health and Well-being Survey (Canadian Community Health Survey (CCHS), Cycle 1.2), 5.3% of the Canadian population aged 15 years and over reported symptoms that met the criteria for a mood disorder in the previous 12 months, including 4.8% for major depression and 1.0% for bipolar disorder.
One in 7 adults (13.4%) identified symptoms that met the criteria for a mood disorder at some point during their lifetime, including 12.2% for depression and 2.4% for bipolar disorder. This lifetime prevalence for bipolar disorder is higher than expected for bipolar 1 disorder, likely because the survey tool was not able to differentiate between manic and hypomanic episodes.
Other studies have reported that between 3% and 6% of adults will experience dysthymic disorder during their lifetime.4
Studies have consistently documented higher rates of depression among women than among men: the female-to-male ratio averages 2:1.8 Men and women have similar rates of bipolar disorder. Women are 2 to 3 times more likely than men to develop dysthymic disorder.
According to the 2002 Mental Health and Well- being Survey (CCHS 1.2), 4.2% of men and 6.3% of women aged 15 years and over reported symptoms that met the criteria for a mood disorder in the previous 12 months: 3.7% and 5.9% of men and women, respectively, met the criteria for major depression; 1.0% of both men and women met the criteria for bipolar disorder.
One in 10 men (10.5%) and 1 in 6 women (16.1%) met the criteria for a mood disorder at some point during their lifetime: 9.2% and 15.1%, respectively, for depression; and 2.4% and 2.3% for bipolar disorder.
In all age groups under the age of 65 years, a greater proportion of women than men reported symptoms that met the criteria for major depression during the previous 12 months and during their lifetime. (Figures 3-1 and 3-2)
Biological or social risk and protective factors may differ between men and women, which may explain the difference in the prevalence of depression. Gender differences in the symptoms that are associated with depression may also contribute to the differences in prevalence. While women express the more "classical" symptoms of feelings of worthlessness and helplessness, and persistent sad moods, men are more likely to be irritable, angry and discouraged when depressed. As a result, depression may not be as easily recognized in men. In addition, women are more likely than men to seek help from health professionals.
In contrast to depression, the proportions of men and women whose reported symptoms met the criteria for bipolar disorder during the previous 12 months and during their lifetime were similar in all age groups. (Figures 3-3 and 3-4)
Mood disorders affect individuals of all ages, but usually first appear in adolescence or young adulthood. The average age of diagnosis of major depressive disorder, however, is in the early twenties to early thirties,9 reflecting the delay in diagnosis.
Young women (15–24 years) had a higher 12-month prevalence of depression than all other age groups for both men and women.
Men and women in the 15–24 year age group had the highest proportion of individuals who met the 12-month criteria for bipolar disorder (1.8%). The 12-month prevalence of bipolar disorder decreased with age.
Among both men and women, the proportion who met the criteria for depression during their lifetime increased into the mid-life years. This reflects the cumulative experience with depression as people age. One in 7 adults aged between 45 and 64 years met the criteria for depression during their lifetime: 1 in 10 men and 1 in 6 women.
About 1 in 50 adults aged 25–44 years or 45–64 years reported symptoms consistent with bipolar disorder at some point in their lifetime. The proportion of men and women who met the lifetime criteria for bipolar disorder decreased slightly with age.
Among senior men and women, both the 12-month and lifetime prevalence of depression were lower than among all younger age groups. The lower lifetime prevalence may reflect either a reluctance to acknowledge symptoms of depression in the past, forgetting of prior episodes, or a real change in the prevalence of depression over time. Seniors may also have developed more effective coping skills during their lifetime. The questions used in the 2002 Mental Health and Well-being Survey (CCHS 1.2) may not have been sensitive enough to identify symptoms of depression specific to seniors. In addition, residents of long-term care facilities were not included in the survey.
The sample size of seniors in the 2002 Mental Health and Well-being Survey (CCHS 2.1) who reported symptoms that met the criteria for bipolar disorder was too small for estimating prevalence.
According to the Canadian Study of Health and Aging (originated in 1991, with follow-up in 1996 and 2001), 2.6% of seniors aged 65+ years had symptoms that met the criteria for major depression and 4.0% had symptoms that met the criteria for minor depression.10 Major depression was defined as having five or more of the nine symptoms of depression during the previous two weeks. Minor depression was defined as having two to four symptoms.
Major depression was more common among seniors living in institutions (7.7%) than among those living in the community (2.2%). It was also more common among individuals with dementia (9.5%) than among those without (2.1%). As with younger age-groups, the prevalence of both major and minor depression was higher among women than men: 3.4% of women compared to 1.5% of men for major depression, and 6.0% of women versus 1.4% of men for minor depression.
Factors associated with depression among seniors included poorer overall health, the interference of health problems with activities, sensory impairment, and presence of chronic disease. Marital status was not found to be associated with depression.
Mood disorders present a serious public health concern in Canada because of their high prevalence, associated economic costs, the risk of suicide, and reduced quality of life.
Major depressive disorder is typically a recurrent illness with frequent relapses and recurrences. The more severe and long-lasting the symptoms in the initial episode (sometimes due to a delay in receiving effective treatment) the less likely is full recovery.
Depression also has a major impact on the mental health of family members and caregivers, whose own depression and anxiety symptoms may increase.
With bipolar disorder, individuals who experience one manic episode tend to have future episodes. Recovery rates vary with the characteristics of the disease: individuals with purely manic episodes fare better than those with both mania and depression, who tend to take longer to recover and have more chronic courses of illness.11
Depression and bipolar disorder cause significant distress and impairment in social, occupational, educational or other important areas of functioning.14 According to the 2002 Mental Health and Well-being Survey (CCHS 1.2), 9 out of 10 Canadians who reported symptoms that met the 12-month criteria for depression (90.1%) reported that the condition interfered with their lives. A similar proportion of those who met the 12-month criteria for bipolar disorder (86. 9%) reported that it interfered with their lives.
According to the World Health Organization (WHO), major depression is among the leading causes of disability-adjusted life years (DALYs) in the world. Depression contributes to 4.5% of DALYs; ischemic heart disease, 3.9%; stroke, 3.3%; all cancer, 5.1%; and HIV/AIDS 5.7%.15
While most individuals with depression or bipolar disorder will not commit suicide, suicide rates are slightly higher than in the general population (approximately 5% versus 1-2%).16 17 (For more details see Chapter 8 – Suicidal Behaviour.)
Child or spousal abuse or other violent behaviours may occur during severe manic episodes. Furthermore, loss of insight often occurs among individuals with bipolar disorder, resulting in resistance to treatment, financial difficulties, illegal activities and substance abuse. Other associated problems include occupational, educational or marital failure. Individuals with bipolar disorder may often have difficulty maintaining steady employment, which may create social and economic disadvantages.
Mood disorders frequently accompany other mental illnesses, such as anxiety disorders, personality disorders and problematic substance use. The presence of another mental illness increases the severity of the initial illness and results in a poorer prognosis.
Depression and bipolar disorder affect life at home, school and work and in social interaction. (Figure 3-5) A higher proportion of individuals with depression than for bipolar disorder reported that their condition had interfered with their lives in each of the four areas. Mood disorders had a greater impact on home and social life than in school and work situations. This could be the result of withdrawing from the work or school environment due to illness.
The high prevalence of mood disorders has a major effect on the Canadian economy. This effect is dual in nature: first, the loss of productivity in the workplace due to absenteeism and diminished effectiveness; and second, the high health care costs attributable to primary care visits, hospitalizations and medication.
A recent discussion paper, "Nature and Prevalence of Mental Illness in the Workplace" highlights the importance and impact of depression in the workplace.20 One of the attributed to depression.21 Work-related principal causes of absenteeism was mental and emotional problems (7% of Canadian workers). Between 62% and 76% of short-term disability episodes due to mental disorders were productivity losses due to depression have been estimated to be $4.5 billion.22
At the individual and family level, the loss of income and cost of medication create a strain on the family financial resources.
Stigma against individuals with mood disorders has a major influence in determining whether an individual seeks treatment, takes prescribed medication or attends counselling. Stigma also influences the successful re-integration of the individual into the family and community.
Attitudes that attribute symptoms of depression among seniors as "just part of aging", contribute to the lack of recognition of clinical depression that can be treated. These attitudes can also prevent seniors from seeking help.
Employers may be concerned that the individual with a mood disorder may be unable to function at the level of other employees. When the illness goes untreated, this may be true. However, with treatment to reduce or manage symptoms, performance usually improves. Addressing the stigmatization of mental illness in the workplace will improve through increased knowledge and an employer's willingness and ability to respond appropriately to an employee's needs.23 Enforcement of human rights legislation can reinforce voluntary efforts.
Mood disorders have no single cause, but several risk factors interact to produce the clinical symptoms of the various mood disorders.
Individuals with depression and bipolar disorder often find a history of these disorders among immediate family members.24 25 Many different genes may act together and in combination with other factors to cause a mood disorder. Research is getting closer to identifying the specific genes that contribute to depression.
One episode of major depression is a strong predictor of future episodes. More than 50% of individuals who have an episode of major depression experience a recurrence.26
Traditionally, stress has been viewed as a major risk factor for depression. Recent research suggests that stress may only predispose individuals for an initial episode, but not for recurring episodes.27 Some individuals are more susceptible than others to depression following traumatic life events, when in difficult or abusive relationships, or as a result of socio-economic factors such as income, housing, prejudice and workplace stress.
A strong association exists between various chronic medical conditions and an increased prevalence of major depression.28 Several chronic medical conditions, such as stroke and heart disease, obesity, Parkinson's disease, epilepsy, arthritis, cancer, AIDS, chronic obstructive pulmonary disease (COPD), and dementia and Alzheimer's Disease may contribute to depression.
This association may result from physiological changes associated with these conditions, such as changes in various neurotransmitters, hormones and the immune system, or from associated disability and poor quality of life. In addition, some medications used to treat physical illnesses tend to cause depression. People who cope with more than one medical condition may be at particular risk for depression. Effective treatment of chronic physical illness includes the assessment, early detection and treatment of depression.
Episodes of mania may occur following physical illness or use of drugs.
Perinatal depression is likely caused by both biological and psychosocial elements, such as hormones, emotions and life circumstances.
A number of risk factors have been identified for postpartum depression. The experience of symptoms of depression during the pregnancy is one risk factor. The "baby blues", a mild mood disturbance that lasts only a few days after birth, can affect up to 80% of women. While generally it does not require treatment,29 30 31up to 20% of women with the baby blues will develop postpartum depression within the first year after giving birth. One in 4 women (25%) with a history of depression is at risk for postpartum depression. Over one-half of women with previous episodes of postpartum depression (50%–62%) are also at risk.32 Other risk factors include lack of social support, low self-esteem, relationship problems and low socioeconomic status.33
Prevention of major depression includes minimizing and coping with stress effectively, and managing chronic disease (focusing on enhancing quality of life and minimizing disability).
Prevention of depression in the perinatal period can include both medication (antidepressants, estrogen therapy and progesterone therapy) and psychosocial support (psychological therapy, antenatal and postnatal classes, intrapartum support, education and early identification).34 35
Mood disorders are treatable. Early recognition and effective early treatment of mood disorders can improve outcomes and decrease the risk of suicide. Given that one episode predisposes an individual to subsequent episodes, relapse prevention with maintenance therapy is also important.
Many people with a mood disorder fail to consult health professionals, however, and suffer needlessly. Of those who do seek treatment, many remain undiagnosed or receive either incorrect or an inadequate amount of medication.36
According to the 2002 Mental Health and Well- being Survey (CCHS 1.2), nearly 1 in 2 respondents who reported symptoms that met the criteria for a mood disorder in the previous 12 months had not consulted with a professional. (Figure 3-6) Family physicians were consulted by the highest proportion of individuals, followed by a psychiatrist, a social worker or a psychologist.
One in five respondents (22.0% of those with depression, and 21.1% with bipolar disorder) reported using natural health products for emotional, mental health, and drug or alcohol use problems.37
Several factors, such as stigma, lack of knowledge or personal financial resources, or lack of available health professionals may discourage people from seeking help for depression or bipolar disorder. Among seniors in particular, mood disorders often go undiagnosed or untreated on the mistaken belief that they are a normal part of aging and that there is no effective treatment.
Primary care settings play a critical role in recognizing and treating mood disorders. Innovative practice models have shown that effective interventions can decrease symptoms and increase workdays.38
Antidepressant medications and various forms of psychotherapy such as interpersonal psychotherapy, cognitive-behavioural therapy— either alone or in combination—have been shown to be effective in treating depression in both teens and adults. A recent publication from the Canadian Psychiatric Association outlines the clinical guidelines for the treatment of depressive disorders.39 Columbia University is currently preparing guidelines for the treatment of depression among children and youth.40 The Canadian Coalition for Seniors Mental Health will soon be releasing national guidelines on the assessment and treatment of depression and of mental health issues in long-term care (focussing on mood and behaviour symptoms).
Individuals with mood disorders may also require hospitalization to adjust medication, to stabilize the disorder or to ensure protection against self-destructive behaviour.
Current initiatives to relieve the burden of mood disorders are focussing on education for individuals and families and for the community. Education is essential, not only to ensure the recognition of early warning signs of depression, mania and suicide and their appropriate assessment and treatment, but also to ensure adherence to treatment in order to minimize future relapses. Sound support networks are crucial during both the acute phase of the illness and the post-illness adjustment to daily life.
Major depression can result in poor productivity and sick leave from the workplace. The workplace, therefore, is an important venue for addressing mental health issues. Supporting the development of healthy work environments, educating employers and employees in the area of mental health issues, and providing supportive reintegration into the work environment for those experiencing mental illness would help to minimize the effect of major depression on the workplace.
Depression in the perinatal period may be difficult for health professionals to detect. As a result, it is often under-diagnosed.41 This may be due to the fact that symptoms of pregnancy can mimic symptoms of depression. Furthermore, depression may develop gradually, healthcare providers may have limited knowledge or expertise in detecting depression, and women may be reluctant to disclose emotions or seek help.42
Interventions and treatment for perinatal depression vary depending on the type and severity of symptoms. Mild to moderate depression may respond to psychotherapy and or social interventions. Partner support and telephone-based peer support have also been shown to be effective.43 44 Severe perinatal depression requires antidepressant medication in addition to psychosocial therapy.45 It is estimated that between 70% and 80% of women with postpartum depression are able to recover with treatment.46