According to the Centers for Disease Control and Prevention (CDC), 7.6 percent of people over the age of 12 have depression in any 2-week period. This is substantial and shows the scale of the issue.
According to the World Health Organization (WHO), depression is the most common illness worldwide and the leading cause of disability. They estimate that 350 million people are affected by depression, globally.
- Depression seems to be more common among women than men.
- Symptoms include lack of joy and reduced interest in things that used to bring a person happiness.
- Life events, such as bereavement, produce mood changes that can usually be distinguished from the features of depression.
- The causes of depression are not fully understood but are likely to be a complex combination of genetic, biological, environmental, and psychosocial factors.
Depression is a mood disorder characterized by persistently low mood and a feeling of sadness and loss of interest. It is a persistent problem, not a passing one, lasting on average 6 to 8 months.
Diagnosis of depression starts with a consultation with a doctor or mental health specialist. It is important to seek the help of a health professional to rule out different causes of depression, ensure an accurate differential diagnosis, and secure safe and effective treatment.
As for most visits to the doctor, there may be a physical examination to check for physical causes and coexisting conditions. Questions will also be asked - "taking a history" - to establish the symptoms, their time course, and so on.
Some questionnaires help doctors to assess the severity of depression. The Hamilton depression rating scale, for example, has 21 questions, with resulting scores describing the severity of the condition. The Hamilton scale is one of the most widely used assessment instruments in the world for clinicians rating depression.
What does not class as depression?
Depression is different from the fluctuations in mood that people experience as a part of normal life. Temporary emotional responses to the challenges of everyday life do not constitute depression.
Likewise, even the feeling of grief resulting from the death of someone close is not itself depression if it does not persist. Depression can, however, be related to bereavement - when depression follows a loss, psychologists call it a "complicated bereavement."
Signs and symptoms
Symptoms of depression can include:
- depressed mood
- reduced interest or pleasure in activities previously enjoyed, loss of sexual desire
- unintentional weight loss (without dieting) or low appetite
- insomnia (difficulty sleeping) or hypersomnia (excessive sleeping)
- psychomotor agitation, for example, restlessness, pacing up and down
- delayed psychomotor skills, for example, slowed movement and speech
- fatigue or loss of energy
- feelings of worthlessness or guilt
- impaired ability to think, concentrate, or make decisions
- recurrent thoughts of death or suicide, or attempt at suicide
The causes of depression are not fully understood and may not be down to a single source. Depression is likely to be due to a complex combination of factors that include:
- biological - changes in neurotransmitter levels
- psychological and social (psychosocial)
Some people are at higher risk of depression than others; risk factors include:
- Life events: These include bereavement, divorce, work issues, relationships with friends and family, financial problems, medical concerns, or acute stress.
- Personality: Those with less successful coping strategies, or previous life trauma are more suceptible.
- Genetic factors: Having a first-degree relatives with depression increases the risk.
- Childhood trauma.
- Some prescription drugs: These include corticosteroids, some beta-blockers, interferon, and other prescription drugs.
- Abuse of recreational drugs: Abuse of alcohol, amphetamines, and other drugs are strongly linked to depression.
- A past head injury.
- Having had one episode of major depression: This increases the risk of a subsequent one.
- Chronic pain syndromes: These and other chronic conditions, such as diabetes, chronic obstructive pulmonary disease, and cardiovascular disease make depression more likely.
Depression is a treatable mental illness. There are three components to the management of depression:
- Support, ranging from discussing practical solutions and contributing stresses, to educating family members.
- Psychotherapy, also known as talking therapies, such as cognitive behavioral therapy (CBT).
- Drug treatment, specifically antidepressants.
Psychological or talking therapies for depression include cognitive-behavioral therapy (CBT), interpersonal psychotherapy, and problem-solving treatment. In mild cases of depression, psychotherapies are the first option for treatment; in moderate and severe cases, they may be used alongside other treatment.
CBT and interpersonal therapy are the two main types of psychotherapy used in depression. CBT may be delivered in individual sessions with a therapist, face-to-face, in groups, or over the telephone. Some recent studies suggest that CBT may be delivered effectively through a computer
Interpersonal therapy helps patients to identify emotional problems that affect relationships and communication, and how these, in turn, affect mood and can be changed.
Antidepressants are drugs available on prescription from a doctor. Drugs come into use for moderate to severe depression, but are not recommended for children, and will be prescribed only with caution for adolescents.
A number of classes of medication are available in the treatment of depression:
- selective serotonin reuptake inhibitors (SSRIs)
- monoamine oxidase inhibitors (MAOIs)
- tricyclic antidepressants
- atypical antidepressants
- selective serotonin and norepinephrine reuptake inhibitors (SNRI)
Each class of antidepressant acts on a different neurotransmitter. The drugs should be continued as prescribed by the doctor, even after symptoms have improved, to prevent relapse.
A warning from the Food and Drug Administration (FDA) says that "antidepressant medications may increase suicidal thoughts or actions in some children, teenagers, and young adults within the first few months of treatment."
Any concerns should always be raised with a doctor - including any intention to stop taking antidepressants.
Exercise and other therapies
Aerobic exercise may help against mild depression since it raises endorphin levels and stimulates the neurotransmitter norepinephrine, which is related to mood.
Brain stimulation therapies - including electroconvulsive therapy - are also used in depression. Repetitive transcranial magnetic stimulation sends magnetic pulses to the brain and may be effective in major depressive disorder.
Severe cases of depression that have not responded to drug treatment may benefit from electroconvulsive therapy (ECT); this is particularly effective for psychotic depression.
Unipolar and bipolar depression
If the predominant feature is a depressed mood, it is called unipolar depression. However, if it is characterized by both manic and depressive episodes separated by periods of normal mood, it is referred to as bipolar disorder (previously called manic depression).
Unipolar depression can involve anxiety and other symptoms - but no manic episodes. However, research shows that for around 40 percent of the time, individuals with bipolar disorder are depressed, making the two conditions difficult to distinguish.
Major depressive disorder with psychotic features
This condition is characterized by depression accompanied by psychosis. Psychosis can involve delusions - false beliefs and detachment from reality, or hallucinations - sensing things that do not exist.
Women often experience "baby blues" with a newborn, but postpartum depression - also known as postnatal depression - is more severe.
Major depressive disorder with seasonal pattern
Previously called seasonal affective disorder (SAD), this condition is related to the reduced daylight of winter - the depression occurs during this season but lifts for the rest of the year and in response to light therapy.
Countries with long or severe winters seem to be affected more by this condition.
Making A level psychology easier
Act directly on the biological mechanism responsible for the abnormal behaviour
Drugs (antidepressants, antipsychotics, anxiolytics)
ECT (Electro convulsive therapy)
Treat symptoms more than causes
Biological treatments act directly on the biological mechanisms that cause, or are involved in, mental illness. This can be, for example, by altering the function or availability of a neurotransmitter, changing the way certain cells in the nervous system function, or removing dysfunctional parts of the nervous system. The three main biological treatments for mental illness are:
- Drug treatments
- Electroconvulsive therapy
Drugs that have been found to usefully treat mental illnesses generally work by changing the amount of a neurotransmitter that is available at a synapse. If, for example, a certain neurotransmitter causes a certain behaviour then stopping the neurotransmitter working, by making less of it available, may reduce the behaviour it causes. Similarly, it may be useful to increase the quantity of a certain neurotransmitter so the the behaviour it affects may be increased.
- Serotonin is a neurotransmitter that has been found to be involved in depression. A class of drugs called SSRIs (selective serotonin reuptake inhibitors) work by stopping nerve cells reabsorbing the serotonin they have released into the synapse, thereby increasing the amount of serotonin that is available. SSRIs are a very effective treatment for depression and include drugs such as Prozac (fluoxetine) and Seroxat (paroxetine).
- Benzodiazepine drugs are commonly used to treat stress, anxiety and high blood pressure. They work by blocking receptors that are usually activated by adrenaline and noradrenaline, meaning that the body is less able to produce extreme and unhealthy sympathetic nervous system responses.
- Another class of drugs that work on noradrenaline synapses is monoamine oxidase inhibitors (MAOIs). These stop the enzyme monoamine oxidase breaking down noradrenaline, and therefore increase the amount of noradrenaline that is available at the synapse. Low levels of noradrenaline in certain areas of the brain has been linked with depression, and so MAOIs are an effective antidepressant.
- Antipsychotic drugs, which are often used to treat schizophrenia, work by reducing the amounts of dopamine at synapses in certain areas of the brain.
Evaluating drug treatments
- Drug treatments have been found to be effective in treating many many illnesses, and in many cases the improvement seen is very quick (e.g. antidepressant drugs may relieve many of the symptoms of depression in just a couple of weeks). However, as is argued by Kirsch & Saperstein (1998), much of the benefit may be due to the placebo effect. The placebo effect is where a drug has an effect simply because the patients expects it to, rather than the actual chemicals in the drug.
- Many drugs have side effects that can, in some cases, be more unpleasant than the illness they are supposed to be treating. Many antidepressants cause nausea, dizziness and even anxiety at first. Antipsychotic drugs may cause movement disorders and tremors. Doctors and patients have to weigh up the possible benefits of using a certain drug against the negative effects it may cause.
- Drugs are an intervention that treat the symptoms of many mental illnesses and do not address the cause. Antidepressants may elevate a person's mood so they are able to return to a normal life, but they do not necessarily address the cause of the depression, which is often psychological.
- The use of drugs to treat mental illness raises many ethical concerns, particularly when they are used in mental institutions against a patent's will. Critics have argued that the drugs are not effectively treating mental disorders, but instead are sedating patients to make them compliant and manageable.
Electroconvulsive therapy involves applying electrodes to a patient's head and passing an electric current through their brain until they have a convulsive fit. It is, for reasons not properly understood, very effective at treating severe depression in patients that do not respond to antidepressant drugs. In 1999 some 11,000 patients were given ECT for depression in England and Wales.
- ECT is a quick and effective method of treating severe depression, and is particularly useful when depressed patients are in imminent danger of harming themselves or committing suicide.
- It is not know how ECT works, but it does seem to increase the levels of certain neurotransmitters in the brain.
- When ECT was first used there were serious side effects, such as broken bones from the convulsions that the treatment causes. However modern use of the treatment is carried out under anaesthetic and with muscle relaxants so injuries are uncommon. There is often memory loss following treatment, but this has been reduced by only applying ECT to one hemisphere of the brain (unilateral) rather than both hemispheres (bilateral).
- ECT is a barbaric-appearing treatment that has been used to punish patents in the post. Today it can only be used when other treatment methods have failed, and only when the patient agrees to it. It can be forced upon patients, but only when they are unable to make a rational decision themselves, and only when they are in imminent danger of self harm.
Psychosurgery is brain surgery to treat psychological disorders. It is the more invasive form of biological therapy because it involves removal of brain tissue and the effects are irreversible, and sometimes unpredictable. The first modern psychosurgery technique was the pre-frontal lobotomy, developed in the 1930s as a cure for schizophrenia and other disorders where patients were aggressive and unmanageable. Lobotomies involved destroying areas of the pre-frontal cortex that are involved in planning and free will, with the result that lobotomised patients became compliant, less aggressive and easy to control. Modern psychosurgery for mental illness is limited to rare procedures such as anterior capsulotomy in extreme cases of obsessive-compulsive disorder, and the removal of tumours that cause behaviour change.
- Psychosurgery is an extremely controversial treatment for mental illness. Before the 1960s it was performed on many thousands of people in an effort to treat otherwise untreatable disorders, and to allow otherwise dangerous patients to leave mental institutions. However, today's treatment methods are so much more advanced that it is almost never necessary to go to the extreme of brain surgery to treat a psychological disorder.
- If psychosurgery is performed today, it will be as a last resort when all other treatments have failed. However there is some surgery that has far more benefit than others, for example anterior capsulotomy in severe anxiety or obsessive-compulsive disorders.
A Level exam tips
Answering exam questions (PSYA2 AQA A specification)
Outline and evaluate biological treatments of abnormality (12 marks)
6 AO1 marks. Describe drug treatments, with elaborated examples, ECT and psychosurgery.
6 AO2 marks. Write a commentary on the effectiveness of drug treatments as it has the most to discuss. Concentrate on the speed and effectiveness, but that it may work due to the placebo effect, that it does not treat the cause only the symptoms, has side effects, and ethical issues. You could also evaluate ECT as a fast and effective treatment, but that it is not know how it works and has side effects.