The Treatment of Depression

Depression is a mental health disorder characterized by symptoms such as continuous low mood, feelings of hopelessness, fatigue, changes in sleep pattern and many more. The World Health Organisation estimates that by 2020 depression will be the second most common cause of disability [1]. This is most concerning. Not only can depression dramatically diminish quality of life but also, if it is left untreated, can be life threatening. However, whilst there are many forms of treatment none of them can be defined as a ‘cure’. Some people have untreatable depression, and some treatments are more effective for certain people than others. Today depression is normally treated via pharmacological or psychological interventions (or a combination of the two).

 

Drug Treatments

Pharmacological treatments use a class of drugs called antidepressants and these support the monoamine theory of depression. This theory states that depression is caused by deficits in two monoamine neurotransmitters in the brain – serotonin and noradrenalin. Antidepressants are therefore considered to work by increasing the levels of serotonin and noradrenalin in the brain. However, there is controversial evidence for this. Firstly, if the monoamine theory of depression is accurate and antidepressants corrected this imbalance, the success rate of antidepressant treatment should be much higher than it actually is (around 65%). Furthermore, the rate of success for people on placebo is staggeringly high (around 30%), which implies a psychological component to recovery [2]. Another finding which takes away from the monoamine theory is from research done into imipramine, one of the first antidepressants developed. Imipramine is a tricyclic antidepressant and some evidence suggests that it actually causes noradrenalin levels in the brain to lower. This would directly oppose the monoamine theory of action [3]. Therefore, since it is not completely clear how depression manifests on a neural level, it can be challenging to create pharmacological treatments that will have a higher success rate.

Psychological Treatments

Psychological interventions include treatments such as cognitive behavioural therapy (CBT), which has a similar success rate to antidepressant treatment. Psychological treatments aim to help patients by altering the way they approach, think about and behave in response to negative thoughts, feelings and situations. CBT has been found to have lower relapse rates than antidepressant treatment, with one study finding that 76% of patients treated with antidepressants relapsed after finishing treatment whilst only 31% of patients treated with CBT relapsed afterwards [4]. Findings such as these could demonstrate some advantages of psychological therapies over pharmacological treatments. Another set of findings show that whilst drug treatments can have negative side effects such as blurred vision, insomnia and headaches, these will not be experienced with psychological treatments [5].

However, whilst there are many advantages to therapeutic treatments over drug treatments, effectiveness of particular therapies will vary from person to person and what is more some therapists will be much better qualified and more effective than others. Furthermore, drug treatments can act much faster than psychological therapy. It therefore follows that for patients with severe or life-threatening depression, drug treatment may be the only option.

 

The power of psychological treatment for mental health disorders, specifically CBT, can be seen through the development of CBT as a treatment for OCD. When initially scanned, patients with OCD had hyperactivity in the orbital frontal cortex as well as in the caudate nucleus and anterior cingulate gyrus as compared with non-OCD participants. The orbital frontal cortex has been shown to fire when errors occur, which would explain its’ over activity in OCD. What was remarkable was that over the course of treatment these hyperactive brain areas associated with OCD were reduced resulting in happier and healthier patients. This therefore demonstrates the power of the mind and thought, since through cognitive behavioural therapy brain structures and their activity were altered [6].

 

Mindfulness

More recently, the technique known as mindfulness has been developed into a psychological treatment designed to follow on from antidepressant treatment in order to reduce relapse rates in depressed patients. Mindfulness teaches people to view certain thoughts and emotions through of an objective lens so they are able to recognize and understand their thoughts and emotions without necessarily internalising them or processing them in a subjective manner. Studies have been carried out in which patients coming off antidepressant treatment underwent an eight week course of mindfulness. This found that relapse rates in these people were reduced by 30% [7].

 

There is currently no cure for depression. The myriad of treatments available do allow for most people suffering from depression to undergo effective treatment and a reduction of depressive symptoms, however many people still relapse, or are not sufficiently treated. With the continual development of new treatments and techniques to reduce depressive symptoms and relapse, especially in the psychological domain, it is hopeful that more efficient treatments, like mindfulness, will continue to be developed. However, in order for a treatment with a truly high success rate to be developed, it may be necessary for researchers to have a better understanding of the mechanisms underlying depression as well as the interaction of these mechanisms.

 

References

[1] Roiser, J. P., Elliott, R. & Sahakian, B. J. (2012) Cognitive Mechanisms of Treatment in Depression. Neuropsychopharmacology, 37(1), 117-136.Cesar, J. & Chavoushi, F. (2013) Background Paper 6.15: Depression. Priority Medicines for Europe and the World.

[2] Insel, T. (2011) Director’s Blog: Antidepressants: A complicated picture. National Institute of Mental Health.

[3] Moncrieff, J. (2008) The Myth of the Chemical Cure: A Critique of Psychiatric Drug Treatment. Palgrave Macmillan, New York.

[4] DeRubeis, R. J., Siegie, G. J. & Hollon, S. D. (2008) Cognitive therapy vs. medications for depression: Treatment outcomes and neural mechanisms. Nature Reviews Neuroscience, 9(10), 788-796.

[5] NHS Choices: Antidepressants – Side Effects

[6] Piet, J. & Hougaard, E. (2011) The effect of mindfulness-based cognitive therapy for prevention of relapse in recurrent major depressive disorder: A systematic review and meta-analysis. Clinical Psychology Review, 31(6), 1032-1040.

[7] Schwartz, J. M. & Begley. S. (2002) The Mind & The Brain: Neuroplasticity and the Power of Mental Force. HarperCollins, New York.

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