The Hmong Sudden Death Syndrome

Vang was a former Hmong (Laotian) soldier who settled in Chicago in 1980, as an escapee of the war in Laos. Lang suffered from traumatic memories of wartime destruction, including severe guilt of leaving his brothers and sisters behind when he fled with his wife and child. According to a mental health team, the culture shock created due to moving from a rural Laos to urban Chicago increased Vang's stress even further. He experienced problems almost immediately.

Vang suffered from sleep issues; he was unable to sleep from the first night in his apartment in Chicago. This continued for the next two days, causing him to visit his resettlement worker, Moua Lee, and confess his problems. He confessed that on the first night, he had woken up suddenly, feeling short of breath from a dream in which a cat was sitting on his chest; and that on the second night, a figure which resembled a black dog came to his bed and sat on his chest, causing him to go out of breath quickly and dangerously. On the third night, a tall, white-skinned female appeared in his bedroom and lay on top of him. Her weight caused difficulty in his breathing, and after 15 minutes, the spirit left and he woke up screaming.

Trauma & Culture

Vang's report attracted scientific interest due to around 25 Laotian refugees in the United States dying of what was termed as the Hmong Sudden Death Syndrome. The victims in those cases also experienced symptoms similar to those Vang did: an exhibition of laboured breathing, screaming, and frantic movements. The US Center for Disease Control investigated these deaths and was unable to find a physical cause. They concluded that the deaths were triggered by a combination of the stress of resentment, guilt over having to abandon families in Laos, and Hmong's cultural beliefs of angry spirits.

The authors of Vang's case study concluded that he might have been a survivor of Sudden Death Syndrome. The role of cultural beliefs is suggested by what happened next. Vang went for treatment to a Hmong woman regarded as a shaman. She told him his problems were caused by unhappy spirits and performed ceremonies to release them. Vang's nightmares and breathing problems during sleep ceased afterwards.

Like the cases of voodoo deaths, Vang's case study suggests that cultural stress and beliefs may have a profound influence on physical well-being. This work was followed by other studies on Hmong immigrants and stimulated interest in the relationship between cultural beliefs and health.

Case Studies

The major limitation of a case study is that it is a poor method for determining cause-effect relations. in most case studies, explanations of behaviour occur after the fact, and there is little opportunity to rule out alternative explanations. The fact that Vang's symptoms ended after seeing a shaman might not have anything to do with his cultural beliefs; it could have been pure coincidence, or other changes in his life could have been responsible.

A second potential drawback concerns on the generalisation of findings: will the principles uncovered in a case study hold true for other people or other situations? The question of generalisability pertains to all research methods, but drawing broad conclusions from a case study can be particularly risky. The key issue is the degree to which the case under study is representative of other people or situations.

A third drawback is the possible lack of objectivity in the way data is gathered and interpreted. Such bias can occur in any type of research, but case studies can be particularly worrisome due to them often being based largely on the researcher's subjective impressions. In science, a skeptical attitude is required for claims based on case studies to be followed up by more comprehensive research methods before being accepted. We should adopt similar skeptical views in our daily lives, too.

Personality and Crime

On the surface, Charles Whitman seemed as solid and as the University of Texas tower from which he rained death on unsuspecting strangers. He was the son of a wealthy family in Florida. Whitman was an outstanding student, an accomplished pianist, one of the youngest eagle scouts in state history, and a former US marine who was awarded the Medal of Good Conduct, as well as the Marine Corps expeditionary medal. He wedded the woman of his dreams, and the couple was even seen as an ideal couple. Whitman became a student of the University of Texas when he was selected for an engineering scholarship by the marines. In his spare time, he served as a scoutmaster in Austin.

So, what caused such a seemingly exemplary person to commit such horrific acts of violence? On December 18, 2001, the Austin History Centre opened its records on Charles Whitman to public scrutiny. The records provide important insight into the complexities of Whitman's personality and the turmoil which existed within him. Although the Whitman incident had happened decades ago, it has a sad reminiscence to more recent acts of violence in schools, workplaces, and communities across the United States.

Whitman's Confession Letter

On a summer evening in 1966, Whitman wrote the following letter:

I don't understand myself these days. I am supposed to be an average, reasonable, and intelligent young man. However, since of late (I am unable to recall the specific day it all started), I have become the victim of many unusual and irrational thoughts. These thoughts tend to recur constantly, and it requires a tremendous mental effort to concentrate on useful and progressive tasks.

In March, when my parents made a physical break, I noticed a great deal of stress. I consulted a doctor, Cochrum, at the university health centre and requested him to recommend someone that I could consult with about some psychiatric disorders that I felt I had. Once I talked with a doctor for about two hours as I tried to convey my fears that I have been feeling overcome by overwhelming violent impulses. After the first session, I never saw that doctor again. And since then, I have been fighting my mental turmoil by myself, and it seems to be to no avail. I wish an autopsy to be done on me when I am dead to find out if there is any visible physical disorder in me. I have had some tremendous headaches in the past and I have consumed two large bottles of Excedrin (Painkiller for migraine headaches) in the past three months.

Later that night, Whitman murdered his wife and mother, both who was loving and supportive of him. The next morning, he carried a high-powered hunting rifle to the top of a 307-foot tower on the busy University of Texas campus in Austin and opened fire on the persons passing below. Within 90 horrifying minutes, he murdered 16 people and wounded 30 others before he was killed by the police.

What is Personality

The concept of personality derives from the fascinating spectrum of human individuality. According to observations, people differ meaningfully according to the ways they customarily think, feel, and act. These distinctive behaviour patterns help in defining one's identity as an individual. According to the noting of one theoretical group, each of us is, in some respects, like all other people, like some others, and like no other person who lived in the past or will exist in the future.

The concept of personality also rests on the observation that any given person seems to behave somewhat consistently over time, and across different situations. From this perceived consistency comes the notion of personality traits that characterizes an individual's customary ways of responding to his or her world. Although only a modest consistency is found from childhood personality to adult personality, consistency becomes greater as we enter adulthood. Nonetheless, even in adulthood, a capacity for meaningful personality change remains.

With the combination of these notions of individuality and consistency, we can define personality as the distinctive and relatively enduring ways of thinking, feeling, and acting that characterize a person's response to life situations.

The thoughts, feelings, and actions that are seen as reflecting an individual's personality typically have three characteristics. First, they are seen as behavioural components of identity that distinguish that person from others; second, the behaviours are viewed as being caused primarily internal rather than environmental factors; and third, the person's behaviour seems to have organization and structure—they seem to fit together in a meaningful fashion, suggesting an inner personality that guides and directs behaviour.

Studies on personality have been guided by psychodynamic, humanistic, biological, behavioural, cognitive, and sociocultural perspectives. These perspectives provide different conceptions of what a personality is and how it functions. Yet this diversity of viewpoints arises from the fact that theorists have their own personalities, which influence their perception and understanding of themselves and the world.

Eating Disorders: Anorexia and Bulimia

According to researchers, the motivation of abnormal behaviour (like seen in anorexia and bulimia) could be caused by the contribution of psychological, environmental, and biological factors. Researchers are unable to experiment on individuals affected by these disorders in order to manipulate possible causes to check if individuals become anorexic or bulimic, but they are able to examine the factors associated with the disorders, as well as the changes that occur in the individuals when they are treated successfully.

Risk Factors

Two college freshmen named Sara and Lisa suffered from eating disorders. Sara was a victim of anorexia nervosa, which was an intense fear of being fat, causing her to severely restrict her food intake to the point of self-starvation. Despite looking emaciated and weighing 85 percent less than a person would be expected to be according to the said person's age and height, anorexic patients continue to view themselves as being fat. Anorexia causes a cease in menstruation, produces bone loss, stresses the heart, and increases risk of death.

Individuals like Lisa, who suffers from bulimia nervosa, are also in fear of getting fat. They tend to binge-eat, after which they purge the food by inducing vomiting or using laxatives. Often individuals suffering from bulimia consume between 2,000 to 4,000 calories during their binges. In some cases, they tend to consume around 20,000 calories per day. Although most bulimics are of normal body weight, repeated purging can cause severe physical consequences; which include gastric problems and badly-eroded teeth. Whereas most anorexics do not see their food restriction as problematic, bulimics typically do. However, they find it extremely difficult to alter their binge-purge pattern.

According to Becker, in 1999, around 90 percent of anorexic and bulimic individuals were women. According to some surveys, up to 10 percent of college women exhibited symptoms of bulimia although the general prevalence among North American women was 1 to 3 percent compared with 0.5 percent for anorexia. The latest statistics will be higher.

Sociocultural Factors

Anorexia and bulimia are more common in industrialized cultures, where being thin is equated to beauty. However, cultural norms alone cannot be held accountable for eating disorders as only a small percentage of women within a particular culture tend to be anorexic or bulimic; personality factors can be part of the issue. Anorexic individuals are often perfectionists. For example; Sara, who was a high-achiever (a highschool valedictorian), strove to live up to lofty self-standards which included strict ideals of an acceptably thin body. For Sara and Lisa, losing weight became a battle for success and control.

Their upbringing too may have played a role in their need for perfectionism and control. According to their description of their parents; they are disapproving, with expectations of abnormally-high achievement standards. For some anorexic children and teens, food refusal may be reinforced by the distress they cause their parents to feel; making self-starvation a way to punish their parents while gaining some control over their lives. As one anorexic patient said in a therapy session: it was like a power thing; I was showing my mother that  I don't need to eat and I can make her mad. The last thing a  parent wants is for you to die. You can get back at anyone, but if I  need to find a way, I had to forgive her as I am killing myself.

For individuals with bulimia, a different pattern from anorexia emerges; tending to be depressed and anxious, with an exhibition of low-impulse control, as well as lacking a stable sense of personal identity. Their food cravings are often caused by stress and negative mood, causing them to binge-eat to temporarily reduce their negative emotional state; followed by feelings of guilt, self-contempt, and anxiety—which is followed by the purging, maybe as a means of reducing these negative feelings.

Genetic Factors

On the biological side, genetic factors appear to predispose some individuals towards eating disorders. The concordance rate of eating disorders is higher among identical twins than among fraternal twins. The concordance rate between first-degree relatives, such as parents and siblings, are also higher than third and fourth-degree relatives. Researchers are searching for specific genes and combination genes that could be contributors to eating disorders.

Anorexia and bulimia exhibit abnormal activity in serotonin, leptin, and other body chemicals. According to the belief of some researchers, neurotransmitter and hormonal imbalances help in the causing of eating disorders; but others propose that the abnormal eating patterns are the initial cause of the chemical changes as a response that, once started, perpetuate eating and digestive irregularities. Other bodily changes also help in the perpetuating of eating disorders. An example of this is the stomach acid which is expelled into the mouth during vomiting, which causes those suffering from bulimia to lose taste sensitivity and also makes the usually unpleasant taste of vomit more tolerable.

Treating eating disorders can be difficult, taking years; but with professional help, around half of all anorexic and bulimic patients are able to make a full recovery while others are able to eat more normally while still maintaining their preoccupation with food and weight.

Psychological Aspects of Hunger

Eating is positively reinforced by the good taste of food and negatively reinforced by hunger reduction. We develop an expectation of eating being pleasurable, making it an important motivation to seek out and consume food. Even the mere thought of food can trigger a feeling of hunger.

Attitudes, habits, and psychological needs also regulate food intake. Have you felt stuffed during a meal yet finished it and gone on to have dessert as well? Beliefs such as not to leave food remaining on your plate, as well as condition habits of autopilot snacking while watching TV, may lead us to eat even when we are not hungry. Conversely, countless dieters tend to restrict their food intake even when hungry.

Social Pressure

Especially for women, such restrictions stem from social pressure to conform to cultural standards of beauty from Playboy centrefolds and beauty pageant contestants and fashion models. It is an indicator of a clear trend towards a thinner and increasingly unrealistic ideal female body shape starting from the 1950s. Given the deluge of "thin = attractive" mass media messages in many parts of the world, it's not surprising that a survey in Australia has revealed that, even though most young women there are of average, healthy weight, only a fifth are happy with it.

Among 12 to 19-year-old Chinese female students, 80 percent are concerned about their weight. Compared with male American high school students, female students are less likely to be overweight, but more likely to diet and think of themselves as overweight. In comparison to men, women became increasingly dissatisfied with their body image throughout the last half of the 20th century.

A study by April Fallon and Paul Rozzin suggests an additional reason for this. Female college students overestimated the needed body average to conform to male preferences, while men overestimated their necessary bulkiness to conform to women's preferences. Women also had the tendency to perceive their body shape as heavier than ideal.

A study in 2004, on American and Spanish men and women, replicated this study with men's overall perception serving to keep them satisfied with their figures, while women's perceptions placed pressure on them to lose weight. Whether it be Caucasian American, African American, or Hispanic American, the men seemed more likely to have ego-protective perceptions about their body shape than women do.

However, men, too, are influenced by cultural ideals. College men's satisfaction with their bodies tend to decrease when exposed to series of advertisements of muscular males, but not when advertisements of average-built men came on. College athletes with value for muscle function tend to believe that women's preference is for a more muscular body type than theirs, making them have a preference of being more muscular than they are. The general consensus is that women's typical need is to be thin, with men who are overweight wanting to be thin and thin men wanting to be more buff.

Environmental and Cultural Factors

Food availability is the most obvious environmental regulator of eating. For millions who live poverty-stricken or famine-ravaged regions, the scarcity of food limits consumption. In contrast, the abundance of high-fat foods in many countries is a contributing factor to a high rate of obesity.

The taste and varieties of food also regulate eating. Foods that taste good increase consumption, but during a meal and from meal-to-meal; we can grow tired of eating the same thing, causing termination of the meal more quickly. In contrast, food variety increases consumption as observed at buffets.

This is because, through classical conditioning, we learn to associate the smell and sight of food with taste; in return, these food cues cause hunger. You may not be hungry and feel no need to indulge yourself unnecessarily, but the sensuous aroma will change your mind, making you feel hungry when you are not, like when you get the smell of baked goods. Even rats who are already full and ignore available foods will eat again with classically conditioned lights and sound settings they are used to associate food with.

Many other environmental stimuli can affect food intake. For example, we tend to eat more when dining with others than when dining alone. Cultural norms influence when, how, and what we eat as well. In Mediterranean countries such as Greece and Spain, they often begin their dinner late evening (around 9 p.m.). By this time, most North Americans have finished their dinner. Also, although we love variety, we tend to be more comfortable with familiar foods, often feeling difficulty overcoming squeamish thoughts of unfamiliar dishes.

Obesity

The heaviest known male and female according to history records were both Americans, weighing 1,400 pounds and 1,200 pounds, respectively, according to the Guinness Book of World Records, in 2000. A few people had approached that weight, but according to the body mass index (BMI), which takes into account the height and weight of an individual; a staggering 25 to 30 percent of American adults are obese, with 30 to 35 percent being overweight. From Canada to the Palestinian west bank, the adult obesity rates recorded are 20 to 50 percent according to many studies.

Being Obese places a great risk on one's health, as well as targets of prejudice and stereotypes. Obesity is often blamed on lack of will-power, a dysfunctional coping mechanism, heightened sensitivity to external food cues, and emotional disturbances. However, researchers have no such consistent findings between obese and non-obese people. There are hormone-related conditions that can cause weight-gain without excess food consumption, too, and hypothyroidism is one of them. South-East Asians tend to stay slim even with high-fat food consumption due to their genes, which means genes may be in play in as well, in cases of obesity.

Historical Perspectives on Mental Disorders

According to historical findings, psychological disorders are not just a modern issue. There are historical pages filled with accounts of prominent people who had suffered from such disorders.

For example, one description is in the Bible about King Saul's raging madness and terrors. The 18th-century French philosopher Jean-Jacques Rousseau developed marked paranoid symptoms in the latter part of his life, which plagued him with fears of secret enemies. Mozart was convinced that he was being poisoned during the period of his composing of Requiem.

Abraham Lincoln had suffered frequent bouts of depression throughout his life. At one occasion, he had been so depressed that he failed to show up at his wedding. Winston Churchill, too, periodically suffered from severe bouts of depression, which he referred to as his 'black dog'. The billionaire aviator Howard Hughes became so terrified of being infected by germs that he ended up a bedridden recluse in the last decade of his life.

Assumptions on Supernatural Forces

This sort of dysfunctional behaviour doesn't go unnoticed. Throughout history, human societies have explained and responded to abnormal behaviours in different ways, at different times, based on their values and assumptions on human life and behaviour. The belief of abnormal behaviour being caused by supernatural forces dates back to the ancient Egyptians, Hebrews, and Chinese.

For example, one ancient treatment based on the notion of bizarre behaviour being the reflection of an evil spirit's attempt to escape from a person's body. In order to release this spirit, a procedure called trephination was performed. This was carried out with the help of a sharp tool, which was used to chisel a hole in that person's skull. The hole was about 2 centimetres in diameter. It seems likely that in many cases, the administration of trephination ended the patient's life.

In Medieval Europe, the demonological model of abnormality believed that disturbed individuals were either possessed involuntarily by the devil or had voluntarily made a pact with dark forces. The killing of witches was justified in various 'diagnostic' tests and theological grounds. Examples of such tests include the binding of a woman's hands and feet throwing her into a lake or pond.

This was based on the notion that while impurities floated to the surface, a woman who would sink and drown could be posthumously declared pure. This meant that while the pure drowned, the others thought to be witches due to floating on top wouldn't be spared either. During the 16th and 17th centuries, more than a 100,000 people afflicted by psychological disorders were identified as witches, hunted down, and executed.

Biological Links

Centuries earlier, around 5th century B.C., famous Greek physician Hippocrates suggested that mental illnesses were just like physical diseases. In anticipation of the modern viewpoint, Hippocrates believed the site of mental illness to be the brain. By the time of the 1800s, Western medicine had returned to viewing mental disorders as biologically based and attempted to extend medical diagnoses to them. The biological emphasis was given impetus by the discovery of General Paresis, a disorder characterised in its advanced stages by mental deterioration and bizarre behaviour, resulting from massive brain deterioration caused by Syphilis. This was a breakthrough as the first demonstration of a psychological disorder being caused by a physical malady.

In the early 1900s, Sigmund Freud's theory of psychoanalysis ushered in psychological interpretations of disordered behaviour. Psychodynamic theories of abnormal behaviour were soon joined in by other models based on behavioural, cognitive, and humanistic conceptions. These various conceptions focused on different classes of causal factors and help in capturing the complex determinants of abnormal behaviour. The importance of cultural factors has received increased attention, too. Although, still, many questions remain, these perspectives have given us a deeper understanding of the way biological, psychological, and environmental factors can combine to cause psychological disorders.

Today, many psychologists find it useful to incorporate these factors into a more generalised framework. According to the Vulnerability-Stress Model, each of us has some degree of vulnerability, ranging from very low to very high, to developing a psychological disorder, faced with sufficient amount of stress. The vulnerability can have a biological basis, such as our genotype, over or underactivity of neurotransmitters in the brain, a hair-trigger autonomic nervous system, or hormonal factor. It may also be due to a personality factor, such as low self-esteem or extreme pessimism, or due to previous environmental factors such as poverty, severe trauma, or loss. Cultural factors, too, can create vulnerability to certain kinds of disorders (Ingram & Price).

However, vulnerability happens to be only part of the equation. In most instances, a predisposition creates a disorder only when a stressor, such as a recent event which requires a person to cope, combined with a vulnerability to trigger the disorder (Van Praag). Thus, a person with a genetic predisposition to depression, or who suffered a traumatic loss of a parent early in life, may be primed to develop a depressive disorder, if faced with a stressor or a loss later in life. In conclusion, biological, psychological, and environmental levels of analysis have all contributed to the Vulnerability-Stress Model, as well as to our understanding of behavioural disorders and their development.

Causal Factors of Mood Disorders

Mood disorders, much like anxiety disorders, are a product of interacting biological, psychological, and environmental factors.

Biological factors

Both neurological and genetic factors have been linked to depression; genetic factors surface in both twin and adoption studies. In identical twins, there is a higher concordance rate of experiencing clinical depression compared to fraternal twins. Among adopted people who develop depression, biological relatives have a higher chance of suffering from depression than adoptive relatives and a predisposition to depressive disorders is more likely to be inherited given certain kinds of environmental factors such as a significant loss, or low social support.

Influential Theory

Considering biological research, the focus has increased on the role of brain chemistry in depression. According to Influential Theory, depression is a disorder of motivational underactivity of a family of neurotransmitters, including dopamine, serotonin, and norepinephrine. These transmitters play important roles in several regions of the brain involved in reward and pleasure.

When neural transmissions in these brain regions decrease, it results in lack of pleasure, and motivational loss, which are characteristics of depression. In support of this theory, several effective antidepressants operate by increasing the activity of these neurotransmitters, further stimulating the neural system which underlies positive mood and goal-directed behaviour.

A study headed by Lescia Tremblay tested the amount of reward experienced by depressed patients when a stimulant drug was used to activate these centres, and individuals who were in severe depression showed a much stronger level of pleasure response to the drug, supporting the hypothesis of a deficit of pleasure in the brain.

Genetic Basis

Later research by Ian Gotlib with the use of fMRI (functional Magnetic Resonance Imaging) readings of emotion areas of the brain showed low neuron responsiveness to happy and sad scenes alike, as if the emotional response system had shut down. This may account for lack of positive emotionality and the empty feelings of depressive emotional experience.

Bipolar Disorder, in which depression alternates with less frequent manic periods, has been studied primarily at a biological level because it tends to have a stronger genetic basis than unipolar depression. Around 50% of patients with the disorder have parents, grandparents, or a child with bipolar disorder as well. Identical twins have a higher chance of developing bipolar disorder than fraternal twins, which suggests a genetic cause.

Manic disorders may stem from an overproduction of the same transmissions which are underactive in depression. Lithium chloride, which is most frequently used to calm manic disorders, is used to decrease the activity of these transmitters in the brain's motivational and pleasure activation system.

Psychological factors

Biological factors can cause a person to be more vulnerable to certain types of psychological and environmental events that can trigger such disorders.

Personality-based Vulnerability

According to the beliefs of psychoanalysts Sigmund Freud and Karl Abraham, early traumatic losses or rejection create vulnerability for later depression by creating a grieving and rage process which becomes part of the individual's personality. Subsequent losses and rejections cause the reactivation of the original loss, causing a reaction not just about the current event, but unresolved losses from the past, too.

British sociologists George Brown and Terrill Harris support Freud's theory of early loss. According to Brown and Harris, out of the women they interviewed in London, the rate of depression was three times higher among those who lost their mothers under the age of 11 and experienced severe recent losses than the women who had similar recent losses but no such previous loss. Experiencing the death of a parent in early childhood can cause an increased risk of depression later in life.

Cognitive process

According to Aron Beck, depressed individuals tend to victimize themselves with the beliefs that they are defective, inadequate and worthless. They feel that everything that happens to them is bad and that bad things will continually happen to them because of their personal defectiveness.

This depressive cognitive triad of negative thoughts concerning the world, oneself, and the future tends to pop up into the conscience automatically. Many depressed people are unable to control or suppress negative thoughts. Depressed individuals recall their failures more often than their successes and tend to focus more on their perceived inadequacies. They detect pictures of sad faces at times of lower exposure times and remember them better than individuals with no depressive disorders, which indicates a perpetual and memory sensitivity to the negative.

Most people take personal credit for the good outcomes in their lives, blaming their misfortunes on outside factors; thereby maintaining and enhancing their self-esteem. This is the opposite of what depressed people do, according to Beck. These individuals exhibit a depressive attributional pattern, which is attributing success or other positive events to factors outside oneself, while attributing negative outcomes to personal factors. According to Beck, not taking credit for success but in addition, blaming themselves for failures helps depressed individuals maintain low self-esteem and beliefs that they are failures.

Learned Helplessness

Another prominent cognitive account of depression referred to as Learned Helplessness Theory holds that depression occurs when people expect the occurrence of bad events and feeling unable to do anything to prevent or cope with them. Even though the depressive attributional pattern plays a central role in the learned helplessness, model learned helplessness theorists have taken it a step further by specifying what the negative attributions for failures are like.

According to them, chronic and intense depression is a result of negative attributions for personal failures. These people, who attribute negative events in their lives to factors such as low levels of intelligence, physical repulsiveness, or an unlovable personality tend to believe that their personal defects will render them helpless, making them unable to avoid negative future events This sense of hopelessness places them at a significantly higher risk of depression.

Behavioural Perspective

The behavioural perspective also has important things to say about depression. According to Peter Livingston, depression is usually triggered by a loss, punishing event, or by a drastic decrease in the amount of positive reinforcement received by an individual's environment. When depression takes hold, people stop performing behaviours that provided them with reinforcement, such as hobbies and socialising.

Depressed individuals, at times, tend to make others anxious. Those persons may lose patience due to their failure to understand why this individual doesn't break the cycle. This can further diminish social support and may cause depressed individuals to be abandoned by those most important to them. According to longitudinal studies, reduction in social support is a good predictor for subsequent depression.

Positive Reinforcement

According to behavioural theorists, for depressed individuals to feel better, they need to break this vicious cycle by forcing themselves to engage in behaviours that would provide them with some degree of pleasure. Eventually, positive reinforcement produced by the process of behavioural activation will begin counteracting the depressive affects undermining the feelings if hopelessness that characterise depression and thereby increasing feelings of personal control over the environment.

Environmental factors may help explain the reason depression tends to run in families. Constance Hammen studied family histories of depressed individuals; his conclusion was that children of depressed parents often experience poor parenting and many stressful experiences growing up. This may result in poor coping skills and a negative self-concept, making them more vulnerable later in life to stressful events, which may trigger depressive reactions. This conclusion is supported by findings that children of depressed parents exhibit a significantly higher incidence of depression and other disorders as adolescents and young adults.

Sociocultural factors

Depression exists virtually in all cultures; but its prevalence, symptom patterns, and causes reflect cultural variations. For example, Hong Kong and Taiwan have a far lesser prevalence rate of depressive disorders compared to Western countries. Individuals in these societies tend to have strong social support from family and other groups, and this helps them through the occurrence of negative impacts of loss and disappointment.

Cultural factors, too, can affect the way depression manifests. For example, in Western European countries and North America, there is a predisposition to feelings of guilt and personal inadequacy. On the other hand, people of Latin, Chinese, and African cultures more often tend to suffer from somatic symptoms of fatigue, loss of appetite, and sleep difficulties.

Finally, according to cultural factors in technologically-advanced countries such as Canada and the United States, women have been reported to be twice as depressed than men. Yet, this sex difference is not evident in developing countries.