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.

Introduction to Mood Disorders

Mood disorders are a set of emotion-based disorders including depression and mania (excessive excitement). Mood disorders, together with anxiety disorders, are the most frequently experienced psychological disorders. Co-occurrence is high in mood and anxiety disorders and around half of depressed individuals suffer from an anxiety disorder as well.

Depression

Almost everyone has experienced some form of depression in the wake of loss or pain, which is an inevitable part of life. When this happens, we tend to be sad, apathetic, passive, and discouraged. The future may look bleak and we may feel that life is worthless. This is a normal reaction and not necessarily a depressive disorder unless an individual has an underlying depressive disorder. Twenty-five to 30% of college undergraduates are said to experience mild depression (Seligman). As the events pass or this person gets accustomed to the new situations, feelings of depression tend to disappear.

In clinical depression, however, it’s not that simple. When a person is clinically-depressed, the intensity, frequency and duration of depressive symptoms tend to be out of proportion to the person’s life situation. For some, even a minor setback or loss can bring about major depression. This can cause an intense state of depression, making it hard to function effectively in their lives.

Dysthymia

This is a less intense form of depression, with less dramatic effects on a personal and occupational function. However, it is a more chronic and long form of misery that can last for years, with some intervals of normal mood that don't last for more than a few weeks or months.

This negative state of mood is the core feature of depression. When questioned about the way they feel, depressed people would report sadness, misery and loneliness. While people with anxiety disorders are capable of retaining a capacity to experience pleasure, depressed people are unable to do so (Mineka). For the depressed, activities that used to bring them satisfaction and happiness tend to be dull and flat. Even biological pleasures such as food and sex lose their appeal.

Even though depression is primarily a mood or emotional disorder, there are three other types of symptoms which are cognitive, motivational, and somatic.

Cognitive Symptoms

Cognitive symptoms are a central part of depression. This makes it hard for depressed people to concentrate and make decisions. They usually have low self-esteem, and tend to believe themselves to be inferior, incompetent and inadequate. When they suffer setbacks, they blame themselves. They even blame themselves for failures that have not yet even occurred. They expect it to occur and believe it to be due to their own inadequacies.

Motivational Symptoms

Motivational symptoms in depression involve an inability to start and perform tasks that can produce pleasure or accomplishment. A student who is depressed may find it hard to get themselves out of bed in the morning, let alone go to class or study. Everything may seem to need too much of an effort. When extreme depressive reactions are present, the person may have to be pushed out of bed, clothed and fed. In severe cases of depression, the person’s movements are slowed down, making him or her talk and walk slowly, with excruciating effort.

Somatic Symptoms

Somatic (bodily) symptoms often include loss of appetite and even weight loss. In mild depression, sometimes there is weight gain due to compulsive eating, as well as sleep disturbances, particularly insomnia. Sleep disturbance and weight loss lead to weakness and hence, adding to the feelings of depression. Depression can also cause loss of sexual desire and response.

Bipolar disorder

When a person only experiences depression, it’s called unipolar depression. In bipolar disorder, depression (which usually is the dominant state), alternates with periods of mania, which is a state of highly-excited mood and behaviour. When in a manic state, mood is euphoric and cognition is grandiose. They see no limit to possible accomplishments and fail to consider negative consequences that may result if their grandiose plans are acted on.

Considering at a motivational level, manic behaviour is hyperactive. A manic person tends to engage in frenetic activities. This can be at work, sexual relationships, or in other areas of life. For example, 19th century composer Robert Schumann produced 27 works during a one-year manic phase, but his productivity ground to a halt when he sank into a depressive phase due to his bipolar disorder (Jamison). People with manic disorder can become very irritable and aggressive when their momentary goals make them frustrated.

When in manic state, speech tends to be rapid or pressured, as if the person needs to utter many words as possible in allotted time With this surge of activity, the need for sleep is lessened. When in a manic state, a person may go on for days continually without sleep, until exhaustion sets in and slows down the mania.

There is no specific age group that suffers the effects of depression. Infants as young as six months who have been separated from their mothers for prolonged periods of time can suffer from depression as well. Symptoms of depression in children and adolescents are as high as adults (Esau & Petermann). According to data from numerous studies, the rate of depression is indicated to be on the rise among young people, with a dramatic increase in onset of depression among 15 to 19-year-olds (Burke). This shows that lifetime prevalence of major depression has increased over decades.

Prevalence

Prevalence of depressive disorders across socioeconomic and ethnic groups are similar, yet there is a major sex difference according to cultures. Although the prevalence of bipolar doesn't differ according to sex, women appear to be as twice as likely as men to suffer from unipolar depression. Women most likely suffer their first episode of depression in their 20’s and men in their 40’s (Keyes & Goldman).

Many people with depressive disorders never seek treatment. The positive aspect of depression is that it usually dissipates over time. After the initial episode, which typically comes on suddenly after a stressful experience, depression typically lasts around 5 to 10 months if untreated (Tollefson).

When a suppressive episode occurs, one in three patterns may follow. In 40% of all cases, clinical depression may not reoccur following recovery. Many other cases show a second pattern: recovery with recurrence. On average, they will remain symptom-free for a possible three years before another depressive episode about the same severity and duration occurs. Over time, the intervals between subsequent episodes tend to become shorter (Rubin).

Manic episodes, though less common than depressive reactions, has a more chance of recurrence. Mania is experienced in less than 1 percent of the population, but more than 90 percent experience recurrence.

Dissociative Disorders

Ordinarily, a personality has unity and coherence, and many facets of self are usually integrated with people making them act, think, and feel with a certain degree of consistency. Memory plays a critical role in this integration connecting the past and present, providing a sense of personal identity which extends over time. 

Dissociative disorders involve the breaking down of normal personality integration, which results in significant alteration of memory or identity. Three such forms can be taken by this disorder are Dissociative Identity Disorder (DID), Psychogenic Amnesia, and Psychogenic Fugue.

Psychogenic Amnesia

A person with psychogenic amnesia responds to a stressful event with extensive yet selective memory loss. Some are unable to recall their past. Others cannot recall specific events, places or people, even though other contents of memory such as memory, as well as cognitive and language skills, remain intact.

Psychogenic Fugue

A more profound dissociative disorder is Psychogenic Fugue, in which a person can lose all sense of personal identity, making such a person give up his or her customary life and wander off to a new, further away location with a new identity.

The fugue (derived from the Latin word fugere meaning 'to flee'), is usually triggered by a highly stressful traumatic event, which could last from a few hours to days—or even years.

Some adolescent runaways have been associated with fugue state. Married fugue victims may wed someone else and even make career changes. The fugue state typically ends when the person suddenly recovers their original identity, waking up mystified and distressed at the event of being in a strange place, under strange circumstances.

Dissociative Identity Disorder

In Dissociative Identity Disorder (DID) (formerly known as multiple personality disorder), two or more separate personalities coexist in one person. DID is the most striking and widely-publicised of the dissociative disorders.

In DID, a primary or host personality appears more often than the others (called alters), but each personality has its own integrated set of memories and behaviour. The personalities may or may not know of each other's coexistence. They can differ in age and gender and can also differ mentally, behaviorally, and psychologically.

Alters

An example of this was a case about a 38-year-old woman named Margaret who was admitted to a hospital with paralysis of her legs following a minor car accident. During her interview, the woman, who was a member of an ultra-religious sect, reported of sometimes hearing a strange voice inside her, threatening to take over completely. The physician's suggestion to her was to let it take over, which led to the report below.

The woman closed her eyes, clenched her fists, and grimaced for a few moments during which she was out of contact with the others in the room. She suddenly opened her eyes and was a different person. She called herself Harriet. Even though as Margaret; she had been paralysed, complained of fatigue, headache, and backache; as Harriet, she felt well and suddenly proceeded to walk around the room unaided.

She spoke scornfully about Margaret’s religiousness, her invalidism, and her puritanical life; professing of her need to drink and go partying, but Margret's interest was only to go to church and read the Bible. At the interviewer's suggestion, Harriet reluctantly agreed to bring Margret back. After more grimacing and fist-clenching, however, Margret reappeared paralysed, complaining of a headache and backache, and completely amnesic of the brief period of Harriet's release from her prison (Nehemiah).

Biological variations

Mental health workers and researchers have reported dramatic differences among the alternate personalities in DID patients. For example, physical health differences, voice changes, and even changes in left and right handedness.

In some patients, one personality’s presence can bring on allergies which aren't present with the other personalities. One patient almost died due to a violent allergic reaction of a bee sting, yet when an alternate personality was stung a week, later there was no such effect.

In female patients, each personality can have a different menstrual cycles, causing the patient to have several periods for a month. In some patients, each personality needs a different eyeglass prescription. One maybe farsighted while the other is nearsighted (Miller).

Causes of DID

According to Frank Putnam's Trauma-dissociation Theory, the development of new personalities occurs due to severe stress. For the vast majority of patients, this begins at early childhood, which is frequently in response to sexual or physical abuse.

According to Putnam's studies of 100 patients, 97 of them had reported severe abuse and trauma in early and middle childhood, which is a time when children's identities are not well-established, which makes it easy for them to disassociate. In response to trauma and their helplessness to resist it, children may engage in something similar to self-hypnosis and dissociate from reality.

They create an alternate identity to help them detach from their trauma, thereby transferring it to a stronger personality which can handle it and numb the pain. According to the theory, over time, the protective functions served by the new personality remains separate in the form of an alternate personality without being integrated to the host personality (Meyer and Osborne, 1987, followed by Putnam, 2000).

DID has become a controversial diagnosis, with some critics questioning the actual occurrence rate, while others question its very existence. Prior to 1970, only around 100 cases of DID had been reported worldwide. Even today, DID is virtually unknown in some cultures, including Japan (Takahashi).

However, after the disorders were published in popular books and movies, there were many additional cases reported. There has been an increase in the number of alternate personalities in a person (Spanos). A person can be so immersed in an imagined role such as an alternate personality), it can make them feel quite real, making them act accordingly (Spanos). Further research into DID can help better understand factors that can explain the production in memory alteration, psychological responses, as well as behaviour.

Anxiety and Somatoform

Anxiety inferred

Anxiety disorders are usually considered to involve anxiety and stress reactions which are vividly experienced by people who suffer from such conditions, and they are often observable. However, in certain other conditions, the underlying anxiety is largely inferred or assumed to be only present rather than being expressed outward.

For example, in somatoform and dissociative disorders, the person affected may not consciously feel anxious because the function of the disorders is to protect the person involved from strong psychological conflict. According to the beliefs of psychodynamic theorists, whatever may be the distress experienced by the person in such disorders, it is less stressful than the underlying anxiety it is being defended against itself.

Somatoform Disorders

Somatoform disorders involve physical complaints or disabilities suggestive of a medical condition but not present with a biological cause and are not voluntarily produced by the patient. People with hypochondriasis become unduly alarmed about any given physical symptom they feel is convincing them of being seriously ill or about to be. People who suffer from pain disorders experience intense pain that is either out of proportion to whatever medical condition they presume to have for which physical basis is unfounded.

Somatoform disorders differ from psychological disorders in which psychological factors cause or contribute to actual medical conditions such as asthma, migraine headaches, hypertension (chronic high blood pressure), cardiac problems, and peptic ulcers. For example, in a person with a peptic ulcer, stress can produce an outpour of peptic acid, causing an actual lesion in the stomach wall resulting in pain, which is caused by actual physical damage. In somatoform disorders, however, no physical basis for pain can be found.

Conversion Disorder

Conversion disorder may be the most fascinating somatoform disorder, in which serious neurological symptoms such as paralysis, blindness, or loss of sensation suddenly occur. Electrophysiological recordings and brain-imaging of such patients indicates that sensory and motor pathways in the brain are intact. People with conversion disorder often exhibit la belle indifference, which is a strange lack of concern of one's symptoms and its implications.

In some cases, the complaint by the patient themselves is psychologically impossible. An example of this is glove anaesthesia, in which a person loses all sensations below the wrist. The hand is served by nerves, which also provide sensory input to the arm and wrist, making glove anaesthesia anatomically impossible.

Trauma-induced Blindness

Even though psychogenic blindness is rare in the general population, researchers have discovered the largest-known civilian group of people in the world with trauma-induced blindness. These people were refugees who had escaped from Cambodia and had later settled in California. They are survivors of the killing fields of Cambodia who were subjected to unspeakable horror at the hands of the Khmer Rouge in the years that followed the Vietnam War.

More than a 150 of these people were functionally blind, even though their eyes appeared intact and electrophysiological monitoring showed stimuli registered to their visual cortex. Many of them reported that the blindness came on suddenly after they witnessed traumatic scenes of murder, meaning this was a psychological manifestation to past trauma.

Underlying Conflict

According to Freud, conversion symptoms are a symbolic expression of an underlying conflict which aroused a tremendous amount of anxiety, causing the ego to keep the conflict in the unconscious, thereby converting the anxiety into a physical symptom. For example, in one of Freud's cases, a young woman who was forced to care for her hostile, verbally abusive, and unappreciative father, had suddenly developed paralysis in her arm. According to Freud, this had occurred when her repressed hostile impulses threatened to break through and caused her to strike her father with that arm.

A combination of psychological and biological vulnerabilities may cause a person to have a predisposition to somatoform disorders. Somatoform disorders tend to run in families, but it isn't clear whether it's a reflection of the role of genetic factors, environmental learning, and social reinforcement for bodily symptoms or both.

Cultural Influence

In addition, some may experience internal sensations more vividly than others, or they may focus more attention on those symptoms. Patients with somatoform disorders are also very suggestible. In one study, somatoform patients were found more responsive to hypnotic suggestions than matched controls. Furthermore, the hypnotic susceptibility scores of conversion patients significantly correlated with the number of conversion symptoms reported by them.

Somatoform disorders have a higher prevalence in cultures that discourage open discussions on emotions or stigmatise psychological disorders. In Western culture subgroups such as the police or the military, discussing feelings and self-disclosing of psychological problems are frowned upon.

In such situations, somatic symptoms may begin to appear as the only acceptable outlet for feelings of emotional distress in such persons. The same may occur in people who are subjected to severe emotional constrictions, making them unable to acknowledge their emotions or verbally communicate them to others.