Biological explanation of depression

Biological explanations of dysfunctional behaviour centres around physiology, and refers to aspects of biology such as genetics and brain functioning. 

The biological explanation of depression specifically refers to two factors: neurotransmitter dysfunction and inherited genes. In terms of neurotransmitter dysfunction, the biological approach would explain that depression is significantly associated with low levels of serotonin, which has been also been associated with many forms of dysfunctional behaviour including excess anger, anxiety, poor social functioning and other mood disorders. Serotonin is believed to have a variety of roles, and affects brain functioning; though it is not known whether depression is caused by serotonin levels, or whether depression causes low serotonin, or if there is another factor causing them both.

In terms of genes, family research - especially twin and adoption studies - has shown there to be a genetic link to depression, and that this suggests some people may carry genes that predispose them to depression and other mood disorders. Thus, depression could be explained in terms of genetic predispositions.

One study which conducted family correlational research into depression was Wender et al. It was an adoption study which looked at whether environment or genetics appeared to be more associated with depression in adopted adults. The study used a sample of 71 adults who had been adopted and who had a mood disorder, and 71 controls with the same mean age who'd also been adopted but did not have a mood disorder. All had been removed from their mothers at a young age. Psychiatric evaluations were conducted of both the biological and adoptive parents to see whether there was a stronger correlation between depression in adopted adults and depression in adopted parents or biological parents. The results showed that there was an eight fold increase in unipolar depression among the biological parents of the adults. In other words, adoptive parents were eight times less likely to have depression, and the biological parents having depression correlated more significantly with depression in the adopted children than the adopted parents having depression. 

Thus mood disorders appear to have a genetic link, and biological psychologists would thus attribute depression to genetics. 

Gender as a cause of crime

Evolutionary psychology, a branch of biological psychology, attempts to explain our behaviour in terms of evolved survival instincts, often revolving around reproduction.

Daly and Wilson were the first to refer to evolution as an explanation for why some turn to crime. They found that most murders are of young males and committed by young males, and explained this in terms of it being the result of extreme competition for women and status between young, unmarried and unemployed men; they were competing for survival. They claimed this explained why this demographic formed a disproportionate amount of the prison population, especially for violent crimes – that males committed more crimes because their ancestors’ role of hunter and protector predisposes them to more risky behaviour than females. 

Study: Daly and Wilson conducted a study, based on their initial findings and theories, which aimed to investigate the link between homicide rates and life expectancy in different areas of Chicago. They conducted a cross-sectional correlation study using data from police records, government records, school records and local demographic records. Daly and Wilson found much variation between homicide rates in different areas of Chicago, with a strong negative correlation between life expectancy and homicide rates. Another key finding was that school absenteeism also negatively correlated with life expectancy, and thus Daly and Wilson concluded that young men from disadvantaged neighbourhoods were expected to live shorter lives, and thus became more likely to engage in risky behaviour such as crime.

Genes and Serotonin

Crime has been found to run in families, but this does not necessarily mean that nurture is responsible for crime. 

One biological explanation of crime is that some people may be predisposed to crime as they differ in terms of genes and serotonin levels. Low levels of serotonin have been associated with mood disorders and aggressive impulsive acts, as serotonin is involved in brain development, whilst some psychologists have claimed that inheriting certain genes or combinations may predispose someone to crime. 


Study: Brunner et al. conducted a case study of a Dutch family upon request of females in the family who were concerned about the behaviour of the males.

5 affected males were involved in the case study, all of whom were affected by borderline mental retardation and tendencies of abnormal violent behaviour including attempted rape and arson.  Urine samples were taken and analysed from the sample, from which Brunner et al found disturbed monoamine metabolism associated with a deficit of MAO A. A mutation in the X chromosome was also identified, which explained why no females were affected as the XX genetic make-up counteracted the mutation. 

MAO A is involved in serotonin metabolism, and thus Brunner et al concluded that the impairment of this gene was the cause of the mental retardation as well as their aggressive behaviour. 

Brain dysfunction theory

The brain dysfunction theory of why people turn to crime emphasises the role of brain dysfunction. 

Much of the behaviour that makes us "civilised", such as self-control and maturity, are controlled by the pre-frontal cortex area of the frontal lobe. Damage to this area is thought to  result in dysfunctional behaviour such as crime. 

Various research has shown that poor functioning in the temporal lobe, such as in the hippocampus, can lead to people not learning from experience, whilst poor functioning in the amygdala has been associated with altered emotionality and outbursts of negative emotion such as anger. There has been significant association between brain dysfunction and murderers, though it is not known if there is a causality between the two and in which direction this might be. 

Study: Raine et al.

41 murderers who'd been referred to the researchers pending their NGRI pleas were involved in this study. They had a range of mental disorders including schizophrenia. There were also 41 age, gender and mental health matched controls.

Participants were injected with a tracer which attached itself to a glucose molecule to enable a PET scan to determine levels of activity in different areas of the brain. Participants were then asked to complete a 32 minute task involving concentrating on targets. 

The results showed reduced glucose metabolism in the pre-frontal cortex of the murderers' brains. The pre-frontal cortex has been associated with impulsivity, and could explain this aspect of criminality. There were also abnormal asymmetries in the limbic area. Two key areas of difference were the amygdala (which is responsible for the managing of emotions) and hippocampus (responsible for learning), which could further enhance our understanding of why some people kill whilst others do not. 

Why the DSM-V is dividing psychiatry (and why you need to know this)

It's not strictly in the syllabus, but if you can fit this seamlessly into an exam question on diagnosing dysfunctional behaviour or disorders, then no doubt the examiner will be impressed.

If you've got a spare ten minutes, check out this article from the New Scientist on opposition to the DSM-V, and why the National Institute of Mental Health has withdrawn its support to the publication of the DSM-V. If not, read my very much condensed summary below.

The DSM-V is due out later this month (May 2013), replacing the current DSM-IV that's been around since the mid-1990s. Essentially, there's been a lot of complaints about the amount of reliance, by both the medical profession and researchers alike, on a psychiatry "bible". 

The main issue is that it's purely symptomatic - it ignores the biological nature of disorders.

Those who advocate psychology as a science want the biological and physical aspects of psychological disorders to be taken into account so that subjectivity isn't such an issue. They use the comparison of being diagnosed with physical illnesses such as cancer on the basis of self-report alone, rather than being screened and tested. (Though, note that not all "physical" illnesses can be tested for, such as IBS). 

Some of the more radical people want the DSM completely scrapped in favour of a biological approach to diagnosis, such as depression being diagnosed on the basis of serotonin, or schizophrenia after dopamine levels have been analysed. Others merely want both symptoms and biology to play a part in diagnosis.

Whatever you think is the right decision, including this in your G543 paper would show your interest in the subject, and could be a valuable evaluation point which makes the examiners stand up and take note. 

Depression - Comparing treatments [Biological, behavioural and cognitive]

Depression is an affective (mood) disorder which affects approximately one in 5 older people, and thus being able to treat depression is obviously very important. 

The biological approach to treating depression

The biological approach assumes that all behaviour has a biological cause, and thus it targets biology when attempting to treat depression. As many biological psychologists believe that depression is caused by neurotransmitter dysfunction, the treatment for depression aims to target this through a form of therapy called drug therapy. 

Drug therapy is specific to the type of disorder that is being treated; anti-psychotics for psychotic disorders, anti-anxiety medication for anxiety disorders, and anti-depressants for affective disorders. 

Anti-depressants aim to treat depression by raising levels of certain neurotransmitters such as serotonin, as low levels of serotonin have been associated with depressed mental states. 

Study: Karp and Frank (1995) carried out a review article on the effectiveness of drug therapy in treating depressed women. Meta-analysis  (combined analysis) of nine pieces of research featuring a total of 520 women with depression showed that adding cognitive therapy to drug therapy was no more effective than merely prescribing anti-depressants. This suggests that drug therapy for depression is sufficient treatment for depression without other components. 

The behavioural approach to treating depression

The behaviourist approach works on the basis that if behaviour is learned, it can also be unlearned, often through the use of Cognitive Behavioural Therapy (or CBT).

The cognitive element of CBT essentially asks the client undergoing therapy to keep a diary of thoughts and beliefs, and then the therapist will work through them in order to challenge negative thought patterns. The behavioural element, focussed on behavioural activation, features the client and therapist planning pleasurable activities (working on the basis of classical conditioning) and providing rewards for non-depressed activities such as being sociable and active (working on the basis of operant conditioning). Thus, the client learns to associate "non-depressed" activities with pleasure and will therefore be more likely to continue in order to get the positive reinforcement of pleasurable activities and feelings. 

Study: Lewinson (1990) refers to the CBT programme of "coping with depression", a skills based programme where people with depression work together in small-groups to relieve their depression through learning skills such as assertiveness, mood monitoring, relaxation and conflict resolution. It used a sample of 69 depressed self-selected adolescents from Oregon, US, who were split into 3 conditions: only adolescent received training, both adolescent and parents received training, and a control group who were put onto a waiting list for therapy. Note that whilst the adolescents received the "coping with depression" course, parents were taught about positive reinforcement for non-depressed activities and positive changes in their children. By the end of the treatment, group 1 had a 43% reduction in depression, group 2 showed a 47% reduction, whilst the control group showed only 5%. All follow up interviews showed depression rates continued to drop over time, suggesting that CBT is valuable in reducing depression in the short and long term, and that positive reinforcement training for parents is also significant.

The cognitive approach to treating depression

The cognitive approach assumes that it is necessary to recognise the importance of internal mental processes such as thought and perception in determining behaviour. In terms of depression, this approach attempts to identify cognitive distortions through therapy, and to challenge them.

One common type of cognitive therapy used to treat depression is Rational Emotive therapy (RET). It was devised by Albert Ellis and aims to target the irrational beliefs that cause depression. It focuses on depressed people's tendency to think catastrophically (worst case scenario) and then challenging the irrational assumptions underlying this tendency. His model is often referred to as the ABC model:

A: Activation (event which triggers depressive thought/depression)

B: belief (main target of therapy; irrational thought/assumption)

C: consequence (what happens as a result; depression)

Study: Beck et al (1978) is one study which looked at cognitive therapies such as RET, comparing their effectiveness to drug therapy. 44 patients diagnosed with depression undergoing therapy (either drug or cognitive) for 12 weeks were monitored. Whilst both groups showed marked improvements, self-report measures and observations made by psychologists suggested that cognitive therapy was substantially more effective in reducing depression and also seemed to be linked to greater adherence (shown by less attrition in the cognitive group).

Similarities:

Both the behavioural and cognitive approaches use face-to-face therapy and recognise the importance of interaction and cognitive elements in treating depression.

None of the approaches are instantaneous; they require a course across several weeks to be effective. 

Differences:

Drug therapy doesn't require much patient-client interaction, nor does it require much effort on the part of the client - this might be more appropriate as lack of energy or concentration is often part of depression. The other two require more effort.

The behavioural approach is the most holistic as it includes both a cognitive and behavioural element, and aims to treat both the depressed person and change their social environment by changing their parents' behaviour. The other two are quite reductionist as they believe depression is simply dispositional in terms of cognition or biology. 

Reductionism

Reductionism is a really key issue in psychology because to some extent it can be applied to every theory, and every approach or paradigm. 

Reductionism refers to the breaking down of complex phenomenon into smaller components. It's the opposite of holism, where complex phenomena are looked at in their entirety.

Reductionism/holism is a continuum rather than an either/or description of a theory or approach. Some of the more reductionist approaches are behaviourism and the biological approach, whilst the more holistic approaches are humanistic psychology, the individual differences approach and social psychology.

Essentially, the more simplistically a behaviour is explained, the more reductionist the theory. 

MANAGING STRESS: Behaviourist Approach and biofeedback [Budzynski et al]

The behaviourist approach to psychology assumes that we are all born as a blank slate, and we learn all of our behaviour. It's a very reductionist approach as it is purely on the nurture side of the nature-nurture debate, the situational side of the situational-dispositional debate, and deterministic on the freewill-determinism debate. 

It essentially works on the basis of three concepts: classical conditioning (learning via association), operant conditioning (learning via punishment and reinforcement) and social learning theory (learning via imitation and interaction with others).

In terms of stress management, the behaviourist approach takes the view that as behaviour is learned, you can be taught to manage stress through the same processes. Stress is often dealt with in behavioural therapies through the use of CBT (mentioned in this post on cognitive therapies) or through the use of positive reinforcements. This often involves direct positive reinforcement in terms of improved relaxation and reduced stress combined with feedback from a biodot (which shows you reducing your stress) or a monitor such as a heart rate monitor.

Study: Budzynski et al 

Budzynski et al conducted a study on the role of biofeedback in reducing stress management. It was a field experiment using 18 volunteers who had responded to an advert asking for people with tension headaches. They were split into 3 conditions. Group 1 were taught relaxation techniques during two weekly sessions for eight weeks, during which they had their muscle tension measured by an EMG machine. They were informed about the biofeedback in terms of clicks, (more clicks = more tension) and encouraged to relax. Group 2 had the same relaxation training but didn't know about the biofeedback and were given a false soundtrack of clicks, whilst Group 3 were not trained in the relaxation techniques nor taught about the biofeedback and so acted as a control group. The study showed that Group 1 had the lowest muscle tension, lowest levels of hysteria and depression and the fewest tension headaches by the end of the study, concluding that biofeedback combined with relaxation techniques help to significantly reduce stress-related illness.