Depression, in psychology, is a mood or emotional state marked by feelings of low self-worth or guilt and a reduced ability to enjoy life. A person who is depressed usually experiences several of the following symptoms: feelings of sadness, hopelessness, or pessimism; lowered self-esteem and heightened self-depreciation; a decrease or loss of ability to take pleasure in ordinary activities; reduced energy and vitality; slowness of thought or action; loss of appetite; and disturbed sleep or insomnia .
Depression symptoms can vary from mild to severe and can include:
1. Feeling sad or having a depressed mood
2. Loss of interest or pleasure in activities once enjoyed
3. Changes in appetite, weight loss or gain unrelated to dieting
4. Trouble sleeping or sleeping too much
5. Loss of energy or increased fatigue
6. Increase in purposeless physical activity (e.g., hand-wringing or pacing) or slowed movements and speech (actions observable by others)
7. Feeling worthless or guilty
8. Difficulty thinking, concentrating or making decisions
9. Thoughts of death or suicide .
Risk Factors for Depression
Depression can affect anyone，even a person who appears to live in relatively ideal circumstances.
Several factors can play a role in depression:
1. Biochemistry: Differences in certain chemicals in the brain may contribute to symptoms of depression.
2. Genetics: Depression can run in families. For example, if one identical twin has depression, the other has a 70 percent chance of having the illness sometime in life.
3. Personality: People with low self-esteem, who are easily overwhelmed by stress, or who are generally pessimistic appear to be more likely to experience depression.
4. Environmental factors: Continuous exposure to violence, neglect, abuse or poverty may make some people more vulnerable to depression .
As the diagram below indicates, the most pronounced commonality between anxiety and depression, at least in terms of emotion, is a feeling of intense energy that is very consuming and hard to shake off.
Depressions that are more biological in their origins (melancholic depression and psychotic depression) are more likely to need physical treatments (antidepressants) and less likely to be resolved with psychological treatments alone. Non-melancholic depression which is linked to psychological factors, personality characteristics and stressful life events, responds to both psychological treatments and physical treatments.
A. Physical treatments.
The main physical treatments for depression comprise drug treatments and Electroconvulsive therapy (ECT).
There are three groups of drugs most likely to be used for depression:
3) Mood stabilizers
2. Electroconvulsive Therapy (ECT)
Because of its controversial past many people feel the need to think carefully before having ECT or allowing it to be given to relatives. Clinicians at the Institute firmly believe that ECT has a small but important role in treatment, particularly in cases of:
1) Psychotic depression
2) severe melancholic depression where there is a high risk of suicide or the patient is too ill to eat, drink or take medications．
3) Life-threatening mania
4) Severe post-natal depression.
In people with depression, the levels of certain brain chemicals are thought to be out of balance, particularly the neurotransmitters serotonin, dopamine, and norepinephrine.
B. Psychological treatments
There are a wide range of psychological treatments for depression. The main ones include:
1) cognitive behavior therapy (CBT)
2) Mindfulness meditation • interpersonal therapy (IPT)
C. Self-help and alternative therapies
There are also a wide range of self-help measures and alternate therapies which can be useful for some types of depression, either alone or in conjunction with physical treatments (such as antidepressants) or psychological treatments. The more biological types of depression (melancholic and psychotic depression) are very unlikely to respond to self-help and alternative therapies alone. However, these therapies can be valuable adjuncts to physical treatments. Self-help and alternative therapies that may be useful for depression are:
2) Relaxation and meditation techniques
3) Good nutrition • alcohol and drug avoidance
7) Light therapy
10) St John's wort＿St John's wort is a herbal treatment that some people take for depression .
The role of serotonin in normal and depressed people with or without SSRIs treatment.
Trials are looking at the effects of botulinum toxins on depression. The idea is that the drug is used to make the person look less frowning and that this stops the negative facial feedback from the face. In 2015 results showed, however, that the partly positive effects that had been observed until then could have been due to placebo effects .
MRI scans of patients with depression have revealed a number of differences in brain structure compared to those who are not depressed. Meta-analyses of neuroimaging studies in major depression reported that, compared to controls, depressed patients had increased volume of the lateral ventricles and adrenal gland and smaller volumes of the basal ganglia, thalamus, hippocampus, and frontal lobe (including the orbitofrontal cortex and gyrus rectus) . Hyperintensities have been associated with patients with a late age of onset, and have led to the development of the theory of vascular depression .
1. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). American Psychiatric Association. 2013.
6. Arnone, D., McIntosh, A. M., Ebmeier, K. P., Munafò, M. R., & Anderson, I. M. (2012). Magnetic resonance imaging studies in unipolar depression: systematic review and meta-regression analyses. European Neuropsychopharmacology, 22(1), 1-16.
7. Herrmann, L. L., Le Masurier, M., & Ebmeier, K. P. (2008). White matter hyperintensities in late life depression: a systematic review. Journal of Neurology, Neurosurgery & Psychiatry, 79(6), 619-624.