Mood disorder: major depression

Mood disorder: Mental disorder characterised by a severe persistent disturbance in a person’s mood that causes psychological discomfort or impairs their ability to function, or both.1

Major depression

A type of mood disorder characterised by one or more major depressive episodes involving symptoms such as intense sadness, loss of interest in everyday activities and a range of negative thoughts, feelings and behaviour.2

Major depressive disorders symptoms include:

  • Depressed mood.
  • Anhedonia (loss of interest and enjoyment)
  • Changes in appetite and weight.
  • Changes in sleep patterns and psychomotor activity.
  • Decreased energy.
  • Feelings of worthlessness or guilt.
  • Difficulty thinking, concentrating or making decisions.
  • Recurrent thoughts of death or suicide.

According to the DSM-IV-TR a person must experience five or more of the possible symptoms. In addition at least one of the five symptoms must persist for a period of at least two weeks and they are required to experience a depressed mood or anhedonia.

Biological contributing factors

Role of genes

Many studies have consistently found that major depression tends to run in families. It has been noted that if one parent has major depression, the risk to their offspring developing the disorder is 25 to 30%. When both parents have the disorder the risk rises to 70%. (Ainsworth 2000).It has also been found that the likelihood of identical twins having depression is higher than if they were non identical (McGuffin & others 1996).There is no widespread agreement on how genes actually influence the development of major depression. It is believed that psychological factors and social factors are still likely to influence the chances of the development of the disease.

Role of neurotransmitters

According to the monoamine hypothesis, major depression is believed to be a consequence of depleted concentrations of serotonin and/or noradrenaline. Serotonin is a neurotransmitter involved in a wide range of psychological activity, including states such as sleep and wakefulness, dreaming, eating, sexual behavior and aggression. Noradrenaline is a neurotransmitter involved in attention, arousal, vigilance alertness and the stress response.

Antidepressant medication in management

Antidepressants are medications designed to relieve symptoms of major depression prescribed by practitioners and psychiatrists.The antidepressants used tend to belong to a class known as serotonin re-uptake inhibitors (SSRIs) .These mediations reduce or block the reabsorption of serotonin by the presynaptic neutrons responsible for the release of the neurotransmitter.SSRIs are the first choice of management followed by serotonin and noradrenaline re-uptake inhibitors.

Psychological contributing factors

Learned helplessness

Learned helplessness is a learned feeling or belief held by an individual suggesting that they are helpless and unable to have any effect on events in their lives and consequently they give up trying (Grivas, 2010).Martin Seligman, the psychologist who founded the idea, postulated that there was a link between learned helplessness and major depression, as sufferers of the illness often come to feel that their actions are pointless and useless.

Stress

The stress exposure model proposes that individuals who have been exposed to a very significant stressor, or have many stressors in their lives will be more likely to develop major depression than those who do not.It is believed stressors involving loss are the stressors most strongly associated with major depression. Two types of stressors have been defined according to this model discrete stressors which are stressors related to significant life events and chronic stressors which are stressors that involve persistent or recurrent difficulties in life.

The Stress generational model refers to the pattern in which individuals with major depression seem to contribute to the occurrence of stressors in their own lives and therefore actually generate stress. (Grivas, 2010).

The reciprocal model combines the stress exposure and stress generation models and proposes a bidirectional (‘two-way’) relationship between stress and depressive symptoms.3 This model suggest that stress can trigger major depression, but individuals can also create or seek stressful events.

Psychotherapies used in the management of major depression

Cognitive behavioral therapy (CBT)

CBT is a type of therapy that combines cognitive and behavioural therapies to help people overcome or more effectively manage schizophrenia. The cognitive component involves helping the sufferer to identify their negative, automatic thoughts they experience as a result of the major depression usually achieved by keeping a thought diary. This is followed by carefully examining each thought and evaluating how realistic it is. Through post identification of these thoughts the aim is to replace them with more realistic, helpful and balanced thoughts. The behavioral component involves using behavioral techniques that are designed to maximize engagement in mood-elevating activities and overcome the behavioral inactivation symptoms such as anhedonia, fatigue, lethargy and lack of motivation. Activity scheduling is one such technique often used as it is aimed at increasing individual’s activity levels and experiences of pleasures.

Psychodynamic psychotherapy

Psychodynamic psychotherapy aims to help people understand the roots of their emotional distress by exploring unconscious conflicts, motives, needs and defenses. The theory behind targeting unconscious thoughts as a means of treatment comes from a theory postulated by Sigmund Freud. Freud believed that major depression is caused by unconscious grief over real or imagined losses. As a result a sufferer will develop feelings of self-hatred and turns this self-hatred inwards developing symptoms of major depression.

During therapy therapists used a range of psychodynamic techniques, these include:

Free association: The client is encouraged to say whatever comes to mind, despite any hostile feelings attached to it. This allows the therapist to look for themes that may be the cause of the person’s depression.

Dream interpretation: By the client sharing their dreams it is believed to help symbolically represent information stored in the unconscious mind.

Search for defense mechanisms: therapists try to make clients more aware of any defense mechanisms they may be using such as denial or transference (when the client unconsciously responds to the therapist as if they are a significant person in their life).

Sociocultural contributing factors

Risk factors associated with major depression

Abuse: This involves psychological and/or physical maltreatment of a person by another, often to intimidate them and to do what the abuser wants.4 This can be in the form of physical abuse, sexual abuse, emotional abuse or neglect. Chronic and severe abuse may predispose an individual to depression. Depressive effects of abuse tend to last longer if experienced at an early age, although it is difficult to isolate the effects of abuse to other factors that may trigger depression such as socioeconomic status.

Poverty: Describes the situation for people in a society who lack the basic necessities of life. These can include basic necessities such as food, water, shelter and clothing, access to health and education as well as social necessities. There are two theories hypothesised to describe the relationship between poverty and major depression. The first one is social drift hypothesis that proposes that having depression impairs psychological and social functioning and this leads to social drift down the socioeconomic scale and ultimately results in poverty. The social causation hypothesis proposes that poverty itself is major contributor to the development of major depression. Both hypotheses have been supported by research however which one is more applicable is dependent on the individual.

Social isolation: Describes the absence of social contacts, interactions and relationships with family, friends, neighbours, colleagues and acquaintances on an individual level and with people in the wider community and society at an age or broader level. This definition is strictly referring to members of the same species. This isolation can be actual or perceived. Studies have shown a strong relationship between social isolation and depression due to what psychologists have described as a human’s basic social needs to feel a sense of belonging and acceptance. Furthermore, social isolation is believed to result in rumination which involves repeatedly thinking about or dwelling on undesirable thoughts and feelings.

Social stressors: Stressors arising from social roles we perform in everyday life that are generally considered problematic or undesirable (Grivas, 2010). These can be interpersonal stressors with family, family and colleagues. Role disputes are another type of stressor and occur when there are unequal guidelines for behavior in a relationship. Another stressor is a role transition that involves an adjustment to a life change that associated with an old role to enable a new role to be performed.

Support factors

Families: Individuals with major depression usually isolate themselves from others. Family members are able to make themselves available to encourage individuals to stick with their treatment and ensure they continue taking their medication if prescribed. Families can also be there to talk to an individual about how they are feeling or try make plans to do something with the individuals if they are experiencing anhedonia.

Social networks: Social networks are the various individuals or groups who maintain relationships with an individual in different aspects of their lives. They are able to provide social support, appraisal support (by ensuring the individual has someone to talk to), tangible assistance (such as help with routine chores) and information support (such as providing them with information regarding helpline service).

Recovery groups: Recovery groups are not-for-profit support groups that aim to help individuals with problem solving strategies to manage the symptoms of depression. A key assumption is that recovery is possible. The group allows for connecting and sharing with other people who are going through or have been through the same things to help to develop and maintain healthy lifestyles. These groups however are not a replacement for support needed from a health professional.

Interaction between biological, psychological and social factors:

Biological, psychological and social factors are not mutually exclusive and rather should be viewed holistically through examination how each of the factors interact to influence one another. For example, an individual can have a genetic predisposition to major depression (biological), live in poverty (social) and as a result may demonstrate learned helplessness (psychological) due to the dire conditions they live under as they do not believe there is any hope of seeing improvement in their life.


  1. Grivas, 2010 

  2. Grivas, 2010 

  3. Grivas, 2010 

  4. Grivas, 2010