Major Depressive Disorder is one of the most common type of clinical depression. Major depression is usually considered a disorder of the young adults. Different people may be affected by depression in different ways. There is no one way that people look and behave the same as others when they have major depression. However, most people will either have depressed mood or general loss of interest in normally enjoyable activities, or a combination of both. In addition they will have other physical and mental symptoms that may include fatigue, difficulty with concentration and memory, feeling of hopelessness and helplessness, headaches, body aches, and thoughts of suicide (American Psychiatric Association [APA], 2000; National Institutes of Mental Health [NIMH], 2008).
Its impact on functioning and well-being can be as damaging to that of chronic medical conditions such as diabetes (Hays, Wells, & Sherbourne, 1995). There were reports that lack of social support may increase the likelihood of that life stress will lead to depression, or the absence of social support may lead to depression directly (Vilhjalmsson, 1993) but it seems that various aspects of personality and its development appears to be integral to the occurrence and persistence of depression (Raphael, 2000). Although depressive episodes are strongly correlated with adverse events, a person's characteristic style of coping may be correlated with their resilience (Sadock, 2002). It is not always clear which factors are causes or which are effects of depression; however, depressed persons who are able to make corrections in their thinking patterns often show improved mood and self-esteem (Warman, &; Beck, 2003).
Diagnosis and symptoms of MDD
In order to be diagnosed with MDD, the symptoms that an individual present have to comply with DSM-IV-TR criteria.
Criteria one is to have at least 5 of the 9 symptoms mentioned in the DSM and the symptoms must last for at least 2 weeks and the patients must show changes from previous behavior. The 9 symptoms includes depressed mood, loss of interest or pleasure in nearly all activity, marked loss or gain in weight, loss of sleep or sleep excessively, activity is agitated or retarded, fatigue, feeling worthless or inappropriately guilty, indecisive or trouble thinking or concentrating, thoughts of death, suicide or had attempt suicide.
The symptoms must cause marked distress or impairment in functioning and must not be caused by alcohol, drugs or medical conditions. Moreover, the symptoms are not better explained by bereavement or the loss of loved one if occurs after loss of love one, symptoms must persist longer than 2 months or be characterized by severe impairment on functioning. The last criteria suggest that the symptoms are not better explained by other psychotic disorder and the individual has never had a manic episode, hypomanic episode or a mixed mood episode.
Categorical or Dimensional
DSM-IV-TR adopted a categorical approach to diagnosing mood disorders. The categorical approach assumed that depression is a discrete mood state, meaning individuals either have depression or they do not. In contrast, dimensional approaches assumed that depression exists along a continuum, ranging from no depressive symptoms to extreme and incapacitating depression.
Researchers are divided on whether depression is categorical or dimensional in adults and adolescents.There were studies involving adults showing that the emotional symptoms of depression such as sadness were continuous, while the physical symptoms of depression, for example sleep and appetite, were categorical. (Beach & Amir, 2003). Whereas, researchers with adolescents suggested that all depressive symptoms fall along a continuum of severity (Hankin et al., 2005).
Statistics of MDD
Several studies have focused on the prevalence and incidence of MDD. However, prevalence and incidence rates vary greatly across different areas (Kessler et al., 2003; Waraich et al., 2004; Eaton et al., 1997). Lifetime prevalence rates for MDD vary widely across countries, ranging from 1.14% to 19.0% (Kessler et al., 2003; Weissman et al., 1996; Kessler et al., 2005). Only 30% to 50% of patients with MDD use health services for depression (Kessler et al., 2003; Hamalainen et al., 2004). The proportion of patients with depressive disorders who receive antidepressant pharmacotherapy at the primary care facilities ranges from 0% to 38% (Simon et al., 2004). Major depression will affect 10%-25% of women and 5%-12% of men. At any one point in time, 5%-9% of women and 2%-3% of men are likely to be clinically depressed (APA, 2000).
Gender difference
Despite the difference in widespread of MDD across different areas, the occurrence of the disorder is roughly consistent among both the genders. In adults, major depressive disorder affects twice as many women as men. Although major depression can occur at any age, the average age for developing the disorder seems to be in a person's mid-20. It is most common in those who are 25-44 years of age, and least common for those over the age of 65 (APA, 2000b; National Mental Health Association, 1999).
It was reported by National Institute of Mental Health (2008) that many women face the additional stresses of work and home responsibilities, caring for children and aging parents, abuse, poverty, and relationship strains that may lead to the occurrence of MDD. It is still unclear why the same or similar challenge causes MDD in woman while others do not.
According to a review of gender differences in depression, it is possible that men tend to distract themselves from their mood by engaging in physical or instrumental activities, whereas women are less active and likely to ponder over the possible causes and implications of their depression (Piccinelli, & Wilkinson, 2000). Women are also more likely than men to suffer from more than one mental disorder. Comorbidity is associated with increased severity of mental illness and disability (Astbury, 2001).
Associative Complications
Relapses for MDD is fairly common (Birmaher, Arbelaze, & Brent, 2002; Birmaher et al., 2004). Approximately 60% in the studies have depressive episode within 2 years after recovery, whereas 70% have another episode within five years of recovery (Simons et al., 2005).
Post and fellows (1996) with the kindling hypothesis tried to explain the tendency of depressed individuals to have recurrence depressive episodes. According to this theory, early depressive episodes sensitize individual to stressful life events and depressions. This suggests that with the increasing experience of the disorder progressively, less severe external conditions can trigger subsequent episodes and probably the onset of major depressive symptoms. Supportive evident were found for the adults but remain untested in children (Monroe & Harkness , 2005; Kendler et al., 2000).
Seligman (1975) hypothesized that feeling of hopelessness and despair contributed to the emergence of depression. Hiroto and Seligman (1975) proposed in another study that learned helplessness might explain for the onset of depression in human.They suggested that people who were exposed to stressful and uncomfortable life events would become passive and depressed. They would not actively cope with stressors but instead succumb to feeling of pain and despair.
Coping
The difference in coping may reveal some evident of the emergence of MDD. Report had shown that 43% of women identify depression as a health problem, compared to only 32% of men National Mental Health Association, 1999). The men are more likely to express their symptoms of depression through substance abuse, such as alcoholism, and antisocial behaviours (National Mental Health Association, 1999). The difference in coping holds true in some other research also. Men are more likely to acknowledge having fatigue, irritability, loss of interest in pleasurable activities, and sleep disturbances, whereas women are more likely to admit to feelings of sadness, worthlessness and/or excessive guilt (Pollack, 1998; Cochran & Rabinowitz, 2000).
The difference to the many different strategies that each individual adopt may also prove to have difference in the onset of MDD. Approach and task-oriented coping are strategies involving problem solving, seeking information and attempts to alter the situation (Ray, Lindop, & Gibson, 1982). In general, people who rely more on approach coping tend to adapt better to life stressors and experience fewer psychological problems (Folkman, & Lazarus, 1988). On the contrary, avoidance and emotion-oriented coping strategies seem to be associated with psychological distress (Suls, & Fletcher, 1985). Avoidance coping describes activities aimed at avoiding the stressful situation and involves denial, wishful thinking and withdrawal (Folkman, & Lazarus, 1988). Emotion-oriented coping describes emotional reactions that are self-orientated in order to reduce stress. These reactions involve emotional responses such that individuals blaming themselves for being too emotional, becoming angry, or tense (Endler, & Parker, 1999).
Health Issue
Poor mental health is one of the main cause of disability and one of the risk factor for a variety of other health problems and conditions. The wealth of factors that are associated with depression includes the increased risk of physical and functional decline, cognitive impairment, ill health, life-threatening malnutrition and weight loss, psychological distress, low self esteem, no devotion to pharmacotherapy for chronic conditions (Gallo & Lebowitz, 1999; Berger et al., 1998). Depressed individuals have a shorter life expectancy than those without depression, in part because depressed patients are at risk of dying by suicide (Cassano, & Fava, 2002). However, they also have a higher rate of dying from other causes and being more particularly susceptible to medical conditions such as heart disease.
There had been reports of patients with several medical illnesses that are associated with increase rate of MDD. Among these are cardiovascular disease, AIDS, respiratory disorders, cancer, and several neurologic conditions such as Parkinson’s disease and stroke (Stoner, Marken, Sommi, 1988; Evans et al., 1999).
Penninx et al. (2001) reported that depression can increase the mortality rate associated with cardiac disease suggesting that mental disorders often co-exist and may worsen the outcome of other medical conditions. There were also studies finding strong association between depression and subsequent cardiovascular morbidity and mortality. Several important physiologic aspects of depression may account for this association. They include sympathomedullary hyperactivity, and diminished heart rate variability (Musselman, Evans, & Nemeroff, 1998).
Suicide
Self-inflicted injuries and suicide represent and remain one of the most serious outcomes of mental health disorders. Suicide is one of the world's leading killers; nearly one million people die each year as a result of suicide (WHO, 2002). Generally speaking, rates of suicide tend to increase in both men and women with age, such that, overall, rates among those aged 75 years and over are approximately three times those aged 15-24 years. Although rates of suicide are higher in older persons, the absolute number of suicides is in fact greater in those under 45 years of age compared with those over 45 years for both men and women (WHO, 2002). A wide range of factors shape an individual's risk for suicide. However, in many cases, these risk factors overlap with one another in complex ways, which makes it difficult to loosen the precise roles played by sex and gender as determinants of suicidal behaviours.
It is likely that the differential impact on men and women of the rapid economic transition which includes increasing poverty and unemployment is linked to gendered differences in social roles and expectations. Men’s whose primary role is that of breadwinner and the primary role of women is of homemaker would be more at risk for depression and suicide behaviour when faced with unemployment and economic crisis. High rates of suicide had been reported among farmers in India, with one of the main reason as economic pressures (Sundar, 1999).
High rate in the male for completed suicide has been partly attributed to the use of more lethal methods of attempting suicide by men, for example, guns. The high ratio in men mortality for other causes is likely to be linked to the fact that men tend to cope with difficult life events by smoking, drinking, and generally undertaking other risk-taking behaviours that can lead to injuries, even death, because these are more generally accepted behaviours for men. Women, in contrast, tend to opt for less lethal means, such as pills and cutting. In some cultures at least, this is a factor which is likely to be heavily influenced by gender, given the greater acceptability in some countries for men to carry guns compared with women (WHO, 2001b).
Life Events
Greater exposure to stressors, such as negative life events, a recognized risk factor for depression, has been proposed as being part of the explanation for the female excess in the risk for depression. Women are also far more likely to be denied educational and occupational opportunities, a gender gap that is especially evident in developing countries (UNDP, 2002). The limitation of opportunities means that women typically have fewer options when faced with economic and social difficulties in their lives, which in turn can lead to a greater likelihood of adverse mental health consequences of negative life events.
Depression is often associated with unemployment and poverty (Weich, Lewis, 1998). There were studies showing MDD were significantly higher for those individuals earning less than $20,000 a year, and declined as income increased (Blazer, Kessler, & McGonagle, 1994). With regard to employment status, homemakers had a very high risk of MDD, but it is not clear whether the employment status has been adjusted for sex gender. Blazer et al. (1994) reported no significant association in adjusted odds ratios for household income. Although these findings are not conclusive, they suggested that socioeconomic status is not a strong risk factor for depression. More evidence were suggested by Patel and Kleinmann (2003) that depression, are more common among those who are living in poverty. The findings implied that the burden of mental disorders is greater for the more economically vulnerable sections of the population.
Jenaway and Paykel (1997) reported that events involving loss for example divorce, death and threat of separation are associated with depression. Kendler et al. (1995) investigated how genetic liability to MDD and stressful life events interact in the etiology of MD in a study of twins. They found that the incidence of depression increased significantly in the occurrence of 13 stressful events. Four of the events, death of a close relative, assault, serious marital problems, and divorce or breakup predicted the incidence of MDD with high odds ratios. Genetic liability also had a significant impact on the onset of MDD. Probabilities of the onset of MDD were substantially higher in individuals with the highest genetic liability suggesting that MDD could be inherited.
Trauma in early life has also been considered a factor in the development of depression by many researchers. Bifulco’s (1991) study of 286 working-class mothers in England, 9% reported childhood sexual abuse. Of these, 64% suffered a depression during the period of study. In another study, Bifulco (1998) found that childhood neglect or abuse can predict early occurrence of depression. McCauley and colleagues (1997) also found that childhood physical or sexual abuse was predictive of a variety of adult afflictions, including depression.
Women are also far more likely than men to be victims of violence, a factor that is also linked to an increased risk for depression (Patel & Kleinman, 2003). Women are more likely to suffer from depression, drug abuse or attempt suicide if they were to be victims of violence or they were abuse by their partner. (WHO, 2002; Patel, Rodrigues & de Souza, 2002). Following rape, one in three women develops post-traumatic stress disorder and depression (Astbury, 2001). Furthermore, women who were sexually abused as children are significantly more likely to suffer depression in adulthood (Astbury, 2001; Patel & Andrew, 2001).
Social Burden
Major depression is currently the leading cause of disease burden in North America and other high-income countries, and the fourth-leading cause worldwide. In the year 2030, it is predicted to be the second-leading cause of disease burden worldwide after HIV, according to the World Health Organization.
Depression results in over 200 million days lost from work each year. Employers have to bear over half, 55 percent, of depression costs to the U.S. in the form of excess absenteeism and lost work productivity (Greenberg, Stiglin, & Finkelstein).
Classified as a severe psychiatric disorder, MDD causes a great economic burden worldwide. The total costs for depression in the United States amounted to about US$83.1 billion in 2000, which may include direct treatment, lost of productivity and excess absenteeism at work. (Greenberg, Kessler & Birnbaum, 2003).
Depression is a treatable disease, yet many people who are depressed do not seek treatment. Individuals with the psychiatric disorder would have their quality of life interfered if the disorder goes untreated. Although there were studies showing that primary healthcare physicians can diagnose and effectively treat older adults who were presented with depression, depression in elderly is frequently underdiagnosed and undertreated in the primary care setting. Only about a third of primary care physician screen and diagnose for depression. As such, only about 15% of older person get treatment for depression. Reasons include the high prevalence of combination medical illness, cognitive impairment, and adverse life events among older persons, as well as the varied and unusual presentation of depression in older adults (Unutzer et al., 1999).
Apart from not getting treated and adding to economic burden, depression can cause limitations in the type or amount of work that can be done and complete withdrawal from the labour force. Study from National Academy on an Aging Society showed that among the 51 to 61 year olds, around 71 percent of people who are depressed reported that a health condition limits the type or amount of work they can do. They may include hearing loss, heart disease, arthritis and diabetes
Treatment
Psychotherapy, medication, and electroconvulsive therapy are the three given treatment. Of which psychotherapy is the choice of treatment for age under 18 and any medications have to be administered with any of the given psychotherapy, such as CBT, interpersonal therapy, or family therapy (NICE, 2005).Electroconvulsive therapy is only used when all else fails. In the treatment of MDD, behavioural therapy, cognitive behavioural therapy, martial therapy, and interpersonal therapy have all been found to reduce depression symptoms. (Craighead, & Ilardi, 1998).
Reports have shown psychotherapy to be effective in older people (Wilson et al., 2008; Cuijpers et al., 2006). Successful psychotherapy appears to reduce the recurrence of depression even after it has been terminated or replaced by occasional booster sessions.More evidence by Angst (1998) showed that depression that is treated has a better course than depression that is untreated. Interventions using behavioural therapy have all brought about significant reduction in depression symptoms. Treatments have also been found to be successful in the sense that the gains of the therapy are maintained.
Patients may be treated with antidepressants other than psychotherapy. People with chronic depression may need to take medication indefinitely to avoid relapse (NIMH, 2008). Although treatment using antidepressants is as effective as psychotherapy, there are evident showing antidepressants have not been found to be beneficial in children (Tsapakis et al., 2008). The FDA has also issue warning of the increased risk of suicidal behaviour in young adults ages 18 - 24 years prescribed with antidepressants.
ECT is usually used for people who does not get better with medications, psychotherapy or supportive interventions and for those at high risk of suicide. It may be the only treatment available for people with severe depression who cannot take medications because of other diseases (APA, 2000).
Conclusions
MDD is a relatively common and severe condition.Although the use of medications and psychotherapy has produced substantial treatment benefits, there are still a proportion of patients with MDD that still relapses. Poor coping strategies, exposure to life stressors, constant economic pressure, association with other diseases, have contributed to the onset and relapses of MDD.
Getting people with MDD to be treated may also prove to be a challenge. With views holding that depression is not an illness, it often goes untreated. The symptoms that shows with MDD does not help also. Different people may be affected in different ways by major depression, thus the difference in symptoms and the difficulty in diagnosis of MDD. There is a need to create public awareness of MDD and bring more to come to know of MDD.
