Biological Explanation Of Depression Essays

Compare and contrast psychological and biological explanations of EITHER major depression OR schizophrenia





This essay compares and contrasts psychological and biological explanations of major depression, the predominant theories used in explaining major depression. Biological theories of major depression refer to genetic and neurochemical level factors used to explain the aetiology of depression while psychological theories of depression look at cognitive and behavioural-level explanations behind clinical depression (Davey 2011). The essay will look at each theory individually before making comparisons in terms of similarities and later contrast them looking at variances, before coming to a conclusion regarding which one offers the best explanation for major depression.

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What is major depression?

This is a clinical disorder characterised by extreme distress to the person, leading to significant diminishment in many areas of life such as occupational effectiveness or social impairment in relating with other people. Persons who are diagnosed with major depression experience long-term maladaptive cognitive patterns lasting beyond 6 months at which point it becomes major depression (Davey 2011). It is characterized by certain physiognomies such as feelings of sadness, apathy, lack of motivation, loss of appetite, irregular sleeping, and general negativity about self or the world (Weissman et al., 1996). 

Psychological explanations of major depression

Psychological explanations of depression refer to those cognitive/mental and behavioural-level causal factors that can be used to explain the aetiology of major depression. Psychological explanations of major depression postulate that the way a person mentally interprets and remembers certain situations can initiate depression. The bulk of theory and empirical research is centred on three major theories; Becks negative cognitive theory (Beck 1967), hopelessness theory (Abramson et al., 1989) and rumination theory (Nolen-Hoeksema 1991).

Negative cognition style

The first theory by Becks (1969) posits that negative cognition/perception or predisposition to negative thinking can precipitate depression.  A person’s perception and appraisal of a major event can make them vulnerable to major depression (Blaney 1977). Experimental studies have for instance shown that depressive states can be induced in participants simply by manipulating their focus of attention or individual beliefs towards the negative, supporting Becks position. Moon et al (1973) requested participants to remember a sad event, focussing their attention on negative and unpleasant thoughts, which influenced their affective state. Other experiments have shown even lowering a person’s belief regarding self-worth and esteem will result in mild depression (Ludwig 1975; Coleman 1975). In other words, negative cognitive bias regarding self, the world and the future, what Becks (1969) refers to as the negative triad, is central to depression. It is also important to remember it is major life events that lead to stress factors precipitating to major depression (Flett and Hewitt 1990; Haaga et al., 1991).

Hopelessness/attribution theory

The second psychological explanation of major depression is the hopelessness theory by Abramson et al (1989) which postulates that onset of depression can be triggered by (a) tendency to negatively attribute the causes of negative events such as an earthquake (b) the tendency to catastrophize the consequences of that negative event, and (c) the tendency to deduce negative characteristics about the self after the negative event (Hankin 2008). 

Rumination theory

The last psychological theory is the rumination response, which represents another cognitive vulnerability factor in major depression. According to Nolen-Hoeksema (2000), people with a ruminative response style in essence “ruminate” repetitively and passively about the negative emotions elicited by negative events, and a number of studies have confirmed this response style predicts depression. For example, a study cited in Nolen-Hoeksema (2000) of college students at the time of the 1989 San Francisco earthquake showed that those possessing a ruminative style before the earthquake experienced elevated depressive symptoms shortly after the earthquake and 7 weeks after it, even controlling for depressive symptoms before the quake (Nolen-Hoeksema & Morrow, 1991). 

Despite significant evidence supporting all three psychological theories in predicting major depression, it is a multifaceted disorder with multiple factors and mechanisms contributing to its ontogeny. Cognitive explanations thus are only a contributory factor, and not a necessary, cause of depression, since persons can become depressed without necessarily showing cognitive vulnerability (Hankin et al., 2009).In the following section, we thus review some of the biological factors that may actually contribute to the emergency and developmental origins of cognitive vulnerabilities that predict depression.


Biological explanations of major depression

According to Davey (2011), biological explanations of major depression postulate that the aetiology of major depression can be down to two factors; genetic vulnerability and neurochemical imbalances.


According to McGuffin et al (1997), human beings are shaped by genetics and much of what a person is or becomes is inherited, including behaviour, temperament as well as disposition to certain diseases. This was illustrated by a study of MZ and DZ twins to determine their concordance rates when it came to major depression. The study showed that concordance rates for MZ twins was 69% compared to just 29% for DZ twins illustrating the genetic likelihood of inheriting major depression, if one twin also had it. 

Neurochemical factors

The second biological cause for major depression is linked to neurochemical factors specifically low levels of neurotransmitters serotonin and norepinephrine, with resulting symptoms similar to affective states of depression. In comparing psychological and biological explanations of major depression, many studies (e.g. Hayden et al., 2008; Lau et al 2006; Lau and Eley 2008; NolenHoeksema and Simen 2007) have actually found supporting evidence that shows biological origins for cognitive vulnerabilities. 

Lau et al (2006) for instance found considerable genetic heritability of attribution styles and depression in MZ twins. Expanding on this study, Lau and Eley (2008) replicated these results, finding moderate genetic links between attribution style and depressive symptoms among non-depressed MZ twins although the specific genes for cognitive vulnerability couldn’t be identified. Hayden et al., (2008) found a more pronounced biased recall of negative words among children having a certain genotype (two copies of the S allele) when a negative mood was induced. These findings were replicated by Sheikh et al., (2008) who found children with 1 or 2 copies of the of the S or LG allele had a higher tendency to negatively attribute the causes of negative events compared to those possessing long alleles.

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Comparison and variance between the two

In comparing and contrasting cognitive and biological explanations of major depression, we can thus deduce the following comparisons and variances between both explanations. Both psychological and biological explanations of major depression can be associated and linked interchangeably as one mechanism that can predict major depression. This has been shown by the many studies that have established gene-cognitive vulnerability interplay and co-relation that leaves persons with certain gene phenotypes vulnerable to negative attribution styles that induce major depression. This link brings both psychological and biological explanations when comparing their explanations of the aetiology of major depression following major negative events.

However, despite this comparison, both explanations have variances than need to be pointed out. First is the fact biological genetic vulnerabilities are natural occurrences that cannot be changed or influenced, which may explain why drugs such as SSRIs are still regarded as ineffective in treating major depression. On the other hand, research on cognitive or psychological explanations of major depression suggests certain cognitive dysfunctions can be influenced through manipulating beliefs, attitudes and environmental cues. Hankin et al (2009) for instance noted that children who face emotional abuse, maltreatment exhibit increases in depression. Thus eliminating such behaviour from their environment can reduce the development of dysfunctional attitudes that lead to psychological vulnerabilities to depression.


Overall, psychological explanations of major depression have more scope for research and influence with a better degree of control in reducing vulnerability to them compared to biological explanations. The fact that variations in environment and experiences of children and adolescents can alter individual cognitions positively or negatively makes for at least efficacious psychotherapeutic work as opposed to biological mechanisms.


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Psychological Theories of Depression

Saul McLeod published 2015

Depression is a mood disorder which prevents individuals from leading a normal life, at work socially or within their family. Seligman (1973) referred to depression as the ‘common cold’ of psychiatry because of its frequency of diagnosis. It is usually quite easy to see when someone is depressed.

Behaviorist Theory

Behaviorism emphasizes the importance of the environment in shaping behavior. The focus is on observable behavior and the conditions through which individuals' learn behavior, namely classical conditioning, operant conditioning and social learning theory. Therefore depression is the result of a person's interaction with their environment.

For example, classical conditioning proposes depression is learned through associating certain stimuli with negative emotional states. Social learning theory states behavior is learned through observation, imitation and reinforcement.

Operant Conditioning

Operant conditioning states that depression is caused by the removal of positive reinforcement from the environment (Lewinsohn, 1974). Certain events, such as losing your job, induce depression because they reduce positive reinforcement from others (e.g. being around people who like you).

Depressed people usually become much less socially active. In addition depression can also be caused through inadvertent reinforcement of depressed behavior by others.

For example, when a loved one is lost, an important source of positive reinforcement has lost as well. This leads to inactivity. The main source of reinforcement is now the sympathy and attention of friends and relatives.

However this tends to reinforce maladaptive behavior i.e. weeping, complaining, talking of suicide. This eventually alienates even close friends leading to even less reinforcement, increasing social isolation and unhappiness. In other words depression is a vicious cycle in which the person is driven further and further down.

Also if the person lacks social skills or has a very rigid personality structure they may find it difficult to make the adjustments needed to look for new and alternative sources of reinforcement (Lewinsohn, 1974). So they get locked into a negative downward spiral.

Critical Evaluation

Behavioral/learning theories makes sense in terms of reactive depression, where there is a clearly identifiable cause of depression. However, one of the biggest problems for the theory is that of endogenous depression. This is depression that has no apparent cause (i.e. nothing bad has happened to the person).

An additional problem of the behaviorist approach is that it fails to take into account cognitions (thoughts) influence on mood.

Psychodynamic Theory

During the 1960's psychodynamic theories dominated psychology and psychiatry. Depression was understood in terms of:

  1. inwardly directed anger (Freud, 1917),
  2. introjection of love object loss,
  3. severe super-ego demands (Freud, 1917),
  4. excessive narcissistic, oral and/or anal personality need (Chodoff, 1972),
  5. loss of self-esteem (Bibring, 1953; Fenichel, 1968), and
  6. deprivation in the mother child relationship during the first year (Kleine, 1934).

Freud’s psychoanalytic theory is an example of the psychodynamic approach. Freud (1917) prosed that many cases of depression were due to biological factors. However, Freud also argued that some cases of depression could be linked to loss or rejection by a parent. Depression is like grief, in that it often occurs as a reaction to the loss of an important relationship.

However, there is an important difference, because depressed people regard themselves as worthless. What happens is that the individual identifies with the lost person, so that repressed anger towards the lost person is directed inwards towards the self. The inner directed anger reduces the individual’s self-esteem, and makes him/her vulnerable to experiencing depression in the future.

Freud distinguished between actual losses (e.g. death of a loved one) and symbolic losses (e.g. loss of a job). Both kinds of losses can produce depression by causing the individual to re-experience childhood episodes when they experienced loss of affection from some significant person (e.g. a parent).

Later, Freud modified his theory stating that the tendency to internalize loss objects is normal, and that depression is simply due to an excessively severe super-ego. Thus, the depressive phase occurs when the individual’s super-ego or conscience is dominant. In contrast, the manic phase occurs when the individual’s ego or rational mind asserts itself, and s/he feels control.

In order to avoid loss turning into depression, the individual needs to engage in a period of mourning work, during which s/he recalls memories of the lost one. This allows the individual to separate him/herself from the lost person, and so reduce the inner-directed anger. However, individuals very dependent on others for their sense of self-esteem may be unable to do this, and so remain extremely depressed.

Critical Evaluation

Psychoanalytic theories of depression have had a profound impact on contemporary theories of depressions. For example, Beck's (1983) model of depression was influenced by psychoanalytic ideas such as the loss of self-esteem (re: Beck's negative view of self), object loss (re: the importance of loss events), external narcissistic deprivation (re: hypersensitivity to loss of social resources) and oral personality (re: sociotropic personality).

However, although being highly influential, psychoanalytic theories are difficult to test scientifically. For example, many of its central features cannot be operationally defined with sufficient precision to allow empirical investigation. Mendelson (1990) concluded his review of psychoanalytic theories of depression by stating:

'A striking feature of the impressionistic pictures of depression painted by many writers is that they have the flavor of art rather than of science and may well represent profound personal intuitions as much as they depict they raw clinical data' (p. 31).

Another criticism concerns the psychanalytic emphasis on unconscious, intrapsychic processes and early childhood experience as being limiting in that they cause clinicians to overlook additional aspects of depression. For example, conscious negative self-verbalisation (Beck, 1967), or ongoing distressing life events (Brown & Harris, 1978).

Cognitive Approach

This approach focuses on people’s beliefs rather than their behavior. Depression results from systematic negative bias in thinking processes.

Emotional, behavioral (and possibly physical) symptoms result from cognitive abnormality. This means that depressed patients think differently to clinically normal people. The cognitive approach also assumes changes in thinking precede (i.e. come before) the onset of depressed mood.

Beck's (1967) Theory

One major cognitive theorist is Aaron Beck. He studied people suffering from depression and found that they appraised events in a negative way.

Beck (1967) identified three mechanisms that he thought were responsible for depression:

  1. The cognitive triad (of negative automatic thinking)
  2. Negative self schemas
  3. Errors in Logic (i.e. faulty information processing)

The cognitive triad are three forms of negative (i.e. helpless and critical) thinking that are typical of individuals with depression: namely negative thoughts about the self, the world and the future. These thoughts tended to be automatic in depressed people as they occurred spontaneously.

For example, depressed individuals tend to view themselves as helpless, worthless, and inadequate. They interpret events in the world in a unrealistically negative and defeatist way, and they see the world as posing obstacles that can’t be handled. Finally, they see the future as totally hopeless because their worthlessness will prevent their situation improving.

As these three components interact, they interfere with normal cognitive processing, leading to impairments in perception, memory and problem solving with the person becoming obsessed with negative thoughts.

Beck believed that depression prone individuals develop a negative self-schema. They possess a set of beliefs and expectations about themselves that are essentially negative and pessimistic. Beck claimed that negative schemas may be acquired in childhood as a result of a traumatic event. Experiences that might contribute to negative schemas include:

  • Death of a parent or sibling.
  • Parental rejection, criticism, overprotection, neglect or abuse.
  • Bullying at school or exclusion from peer group.

However, a negative self-schema predisposes the individual to depression, and therefore someone who has acquired a cognitive triad will not necessarily develop depression. Some kind of stressful life event is required to activate this negative schema later in life. Once the negative schema are activated a number of illogical thoughts or cognitive biases seem to dominate thinking.

People with negative self schemas become prone to making logical errors in their thinking and they tend to focus selectively on certain aspects of a situation while ignoring equally relevant information.

Beck (1967) identified a number of systematic negative bias' in information processing known as logical errors or faulty thinking. These illogical thought patterns are self-defeating, and can cause great anxiety or depression for the individual. For example:

  1. Arbitrary Inference. Drawing a negative conclusion in the absence of supporting data.
  2. Selective Abstraction. Focusing on the worst aspects of any situation.
  3. Magnification and Minimisation. If they have a problem they make it appear bigger than it is. If they have a solution they make it smaller.
  4. Personalization. Negative events are interpreted as their fault.
  5. Dichotomous Thinking. Everything is seen as black and white. There is no in between.

Such thoughts exacerbate, and are exacerbated by the cognitive triad. Beck believed these thoughts or this way of thinking become automatic. When a person’s stream of automatic thoughts is very negative you would expect a person to become depressed. Quite often these negative thoughts will persist even in the face of contrary evidence.

Critical Evaluation

Alloy et al. (1999) followed the thinking styles of young Americans in their early 20’s for 6 years. Their thinking style was tested and they were placed in either the ‘positive thinking group’ or ‘negative thinking group’. After 6 years the researchers found that only 1% of the positive group developed depression compared to 17% of the ‘negative’ group. These results indicate there may be a link between cognitive style and development of depression.

However such a study may suffer from demand characteristics. The results are also correlational. It is important to remember that the precise role of cognitive processes is yet to be determined. The maladaptive cognitions seen in depressed people may be a consequence rather than a cause of depression.

Learned Helplessness

Martin Seligman (1974) proposed a cognitive explanation of depression called learned helplessness. According to Seligman’s learned helplessness theory, depression occurs when a person learns that their attempts to escape negative situations make no difference.

As a consequence they become passive and will endure aversive stimuli or environments even when escape is possible.

Seligman based his theory on research using dogs.

A dog put into a partitioned cage learns to escape when the floor is electrified. If the dog is restrained whilst being shocked it eventually stops trying to escape.

Dogs subjected to inescapable electric shocks later failed to escape from shocks even when it was possible to do so. Moreover, they exhibited some of the symptoms of depression found in humans (lethargy, sluggishness, passive in the face of stress and appetite loss).

This led Seligman (1974) to explain depression in humans in terms of learned helplessness, whereby the individual gives up trying to influence their environment because they have learned that they are helpless as a consequence of having no control over what happens to them.

Although Seligman’s account may explain depression to a certain extent, it fails to take into account cognitions (thoughts). Abramson, Seligman, and Teasdale (1978) consequently introduced a cognitive version of the theory by reformulating learned helplessness in term of attributional processes (i.e. how people explain the cause of an event).

The depression attributional style is based on three dimensions, namely locus (whether the cause is internal - to do with a person themselves, or external - to do with some aspect of the situation), stability (whether the cause is stable and permanent or unstable and transient) and global or specific (whether the cause relates to the 'whole' person or just some particular feature characteristic).

In this new version of the theory, the mere presence of a negative event was not considered sufficient to produce a helpless or depressive state. Instead, Abramson et al. argued that people who attribute failure to internal, stable, and global causes are more likely to become depressed than those who attribute failure to external, unstable and specific causes. This is because the former attributional style leads people to the conclusion that they are unable to change things for the better.

Critical Evaluation

Gotlib and Colby (1987) found that people who were formerly depressed are actually no different from people who have never been depressed in terms of their tendencies to view negative events with an attitude of helpless resignation.

This suggests that helplessness could be a symptom rather than a cause of depression. Moreover, it may be that negative thinking generally is also an effect rather than a cause of depression.

Humanist Approach

Humanists believe that there are needs that are unique to the human species. According to Maslow (1962) the most important of these is the need for self-actualization (achieving out potential). The self actualizing human being has a meaningful life. Anything that blocks our striving to fulfil this need can be a cause of depression. What could cause this?

  1. Parents imposing conditions of worth on their children. I.e. rather than accepting the child for who s/he is and giving unconditional love, parents make love conditional on good behavior. E.g. a child may be blamed for not doing well at school, develop a negative self-image and feel depressed because of a failure to live up to parentally imposed standards.
  2. Some children may seek to avoid this by denying their true self and projecting an image of the kind of person they want to be. This façade or false self is an effort to please others. However the splitting off of the real self from the person you are pretending to be causes hatred of the self. The person then comes to despise themselves for living a lie.
  3. As adults self actualization can be undermined by unhappy relationships and unfulfilling jobs. An empty shell marriage means the person is unable to give and receive love from their partner. An alienating job means the person is denied the opportunity to be creative at work.


Abramson, L. Y., Seligman, M. E., & Teasdale, J. D. (1978). Learned helplessness in humans: critique and reformulation. Journal of abnormal psychology, 87(1), 49.

Alloy, L. B., Abramson, L. Y., Whitehouse, W. G., Hogan, M. E., Tashman, N. A., Steinberg, D. L., ... & Donovan, P. (1999). Depressogenic cognitive styles: Predictive validity, information processing and personality characteristics, and developmental origins. behavior research and therapy, 37(6), 503-531.

Beck, A. T. (1967). Depression: Causes and treatment. Philadelphia: University of Pennsylvania Press.

Beck, A. T., Epstein, N., & Harrison, R. (1983). Cognitions, attitudes and personality dimensions in depression. British Journal of Cognitive Psychotherapy.

Bibring, E. (1953). The mechanism of depression.

Brown, G. W., & Harris, T. (1978). Social origins of depression: a reply. Psychological Medicine, 8(04), 577-588.

Chodoff, P. (1972). The depressive personality: A critical review. Archives of General Psychiatry, 27(5), 666-673.

Fenichel, O. (1968). Depression and mania. The Meaning of Despair. New York: Science House.

Freud, S. (1917). Mourning and melancholia. Standard edition, 14(19), 17.

Gotlib, I. H., & Colby, C. A. (1987). Treatment of depression: An interpersonal systems approach. Pergamon Press.

Klein, M. (1934). Psychogenesis of manic-depressive states: contributions to psychoanalysis. London: Hogarth.

Lewinsohn, P. M. (1974). A behavioral approach to depression.

Maslow, A. H. (1962). Towards a psychology of being. Princeton: D. Van Nostrand Company.

Seligman, M. E. (1973). Fall into helplessness. Psychology today, 7(1), 43-48.

Seligman, M. E. (1974). Depression and learned helplessness. John Wiley & Sons.

How to reference this article:

McLeod, S. A. (2015). Psychological theories of depression. Retrieved from

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