A low level of certain brain chemicals called neurotransmitters can result in depression. Neurotransmitters are what enable the different parts of the brain to communicate. When there are not enough neurotransmitters and miscommunication within the brain occurs, it can create the feelings of depression. Biochemical imbalance is not always a cause of depression, but if it is, it is almost always treated with medication of some kind to help create a better chemical balance in the brain. Many times, an individual who is depressed might have some kind of biochemical imbalance as well as another, non-chemical factor involved; together, they can create a debilitating depression. Usually medication will help to ease the depression, and counseling can help the person to deal with the other factor(s) behind the depression.

Feeling alone does not mean that a depressed person has no significant relationships; it might just be that the person feels misunderstood, unappreciated, has been deeply hurt by friends or family members, or is dealing with other emotional and situational factors that cause him to feel alienated. Loneliness comes and goes for almost all people at different times in life; for some, however, if it is a strong enough sensation and is persistent for enough time, it can lead to feelings of depression. The depression itself usually causes a person to feel even more alienated, which exacerbates the original feelings of loneliness, which cause more depression. It can be a cycle and needs to be resolved by talking about the feelings themselves, why they are there, if they are valid, and how to deal with them in a positive way.

Stress is another common life thread. We all experience different levels of stress at different times in our lives; given enough stress in a short enough period of time, feelings of depression almost naturally result. The stress may be induced by a strained or broken relationship, by a major life change such as a new job or a move to a different location, or by physical illness or pain, or financial difficulty. Depression is more likely to result from stress if: 1) a person is already prone to depression (has a chemical imbalance or other depression-causing factors), 2) if the stress is very intense and/or goes on for a long time, or 3) several situations that cause severe stress occur simultaneously or within a short period of time.

We don't always like to revisit the past, especially the painful parts of it. But if there are significant hurts from the past that have not been resolved, they can continue to effect us in the present. For example, if a child was abandoned by one of his/her parents, he/she may feel unworthy, unloved, and unwanted. Even though the child will grow up and be able to say, as an adult, "That was my parent's problem and it was not my fault," those emotions from the actual experience of abandonment still linger in the heart. It is important that there be time and attention given to talking about the experience and the resulting emotions and how they may still be effecting the person in adulthood. The emotions will not necessarily go away, but knowing what they are and why they exist can help a person to deal with them in a better way, rather than letting them create depression.