A depressed person may have a suicidal tendency as he thinks he is a worthless person and a burden on earth. Sometimes, thoughts of suicide may occur even if the person has no plan to carry it out. Such thoughts are generally involuntary and they enter into the mind on their own. Though most people with such thoughts don’t act on them, but the risk remains high.

The person has a diminished ability to make decisions on his own as he is not able to concentrate on the situation in hand. The task seems much too huge, and he does not have the energy and interest to think and chalk out a way. Serotonin is very important for regulating sleep. Its reduction interferes in normal sleep which can further cause brain fog.

A depressed person underestimates his worth and thinks he has nothing of value to contribute to the world. Such people sometimes get affected by dissociative identity disorder where they think themselves to be another person of high reputation but ultimately when they realize the truth, it pushes them further into depression. This condition is caused by the reduction of dopamine levels inside the brain.

Fatigue is fueled by depression. A depressed person feels like he has no energy. He experiences the type of headaches never felt before, feels pain and low energy in muscles and joints, restless sleep, problems in digestion, and respiratory problems etc.

The person shows a clearly noticeable lack of interest in his day to day activities. He does not enjoy anymore the activities he loved at one point of time. Reduction in norepinephrine transmission leads to this condition and it gets worse as the transmission levels decrease further.

Mood swings are one of the major signs of depression. A depressed person might feel alright at one moment, but suddenly his depression might reach its peak and he is thrown back in to the ocean of sadness. Such a person cries frequently as this gives him some relief. In the course of a day, the mood changes from excitement and happiness, to anger and sadness. The imbalance in the neurotransmitters, especially norepinephrine, leads to mood swings.

Depression causes loss of appetite and constipation in a person. As we know, depression makes a person lose interest in their surroundings, and so he loses interest in eating too. People even feel tired while preparing meals for themselves. All this leads to the person eating less and, ultimately, it results in weight loss. Changes in the levels of serotonin inside the brain causes a person to change his way of eating and ultimately his weight fluctuates.

A depressed person suffers from lack of sleep called insomnia, or in some rare cases with hypersomnia. Even if this was not enough, insomnia prolongs depression. A depressed person is not only unable to sleep but the sleep pattern is also disturbed. In normal sleep we go from the relaxed sleep to dream sleep which is marked by fast eye movements and striking brain activity. The lack of serotonin transmitter is the main reason behind insomnia. Almost 85% of depressed people suffer from insomnia.

Anxiety refers to various mental states like nervousness, apprehensiveness, worry and fear. They affect how we behave and feel, and can cause some real psychological problems. In case feelings of anxiety don’t abate and begin to interfere in the daily functioning of our life, it could ultimately lead to depression. The imbalance created in the neurotransmitters levels and the increase in progesterone secretion are the main causes of this disorder. About one out of four Americans suffer from anxiety but luckily there are centers like Johns Hopkins which provide effective treatment.