Considered as one of the most common psychiatric conditions, depression is defined as a mental health problem in which the person feels a sad mood for a long period of time. Current statistics show that one out of four adults experience depression. 


People diagnosed with depression have a depressed mood for the most part of their days. They have a significant decline of interest in the activities that they used to love, and even in activities that they need such as eating and taking a bath. They can either experience oversleeping or insomnia, and may also be either overweight or underweight.  Depressed people have appetite disturbance, chronic tiredness, low energy level, decreased concentration and attention, and feelings of self-deprecation, low self-esteem and inadequacy. Furthermore, people with depression have recurrent thoughts of death. Due to this, they may have an expressed desire to die. They are highly at risk for suicide.

Biological Basis

Serotonin is the neurotransmitter related to feelings, mood and emotions. This substance is also associated with appetite, sleep, alertness and energy. When a person experiences a high level of stress for a long period of time, his brain uses more serotonin to keep up. As it uses serotonin in such a rate that it cannot balance out serotonin use and serotonin production, the serotonin levels drop, causing depression. Diminishing serotonin levels result to the symptoms of depression that were mentioned earlier in this article.

Aside from serotonin, norepinephrine is another neurotransmitter that is found to be lower throughout the depressive episodes. Abnormally high activity in the site for norepinephrine synthesis, locus coeruleus, may also be associated with depression. Other neurotransmitters such as acetylcholine (AcH) and GABA may be related to depression. AcH is a potent stimulator of the locus coeruleus, while GABA is a potent inhibitor of it. Therefore, excessive AcH levels and abnormally low GABA levels may contribute to depression.

Another biological cause is the intake of drugs that disturb amine transmitter systems by decreasing amine levels. This is the reason why antidepressant medications aim to raise amine levels in the brain.


Mild depression is usually managed through psychological treatment. The psychologist or therapist will assist the patient in sorting out thoughts that have piled up due to highly stressful events during his life for the past months. The therapist will help the patient rebuild self-esteem, concentration and self-appreciation. Mild depression may or may not require medication treatment. Antidepressants such as Prozac, Paxil and Zoloft aim to increase the levels of serotonin in the brain.

Full reference: 

(Mar 25, 2013). Depression. Retrieved Apr 23, 2024 from

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