Depression is something that every person in the world has experienced. Generally, most cases of depression are temporary and mild. Technically speaking, whenever you are sad over something, an event, a disappointment, the loss of an item, friend or loved one. As rule, that sadness doesn’t last.

However, some forms of depression are more severe and longer lasting and fall under the definition of clinical depression. Signs of clinical depression include:

• Feelings of sadness, tearfulness, emptiness or hopelessness
• Angry outbursts, irritability or frustration, even over small matters
• Loss of interest or pleasure in most or all normal activities, such as sex, hobbies or sports
• Sleep disturbances, including insomnia or sleeping too much
• Tiredness and lack of energy, so even small tasks take extra effort
• Reduced appetite and weight loss or increased cravings for food and weight gain
• Anxiety, agitation or restlessness
• Slowed thinking, speaking or body movements
• Feelings of worthlessness or guilt, fixating on past failures or self-blame
• Trouble thinking, concentrating, making decisions and remembering things
• Frequent or recurrent thoughts of death, suicidal thoughts, suicide attempts or suicide
• Unexplained physical problems, such as back pain or headaches

Here in the United States, depression affects more than 18 million adults every year. Depression can be so severe that for ages 15-44, it is the leading cause of disability. It leads to the loss of around 490 million days of work every year here in the US, which amounts to a yearly loss of about $23 billion. The overall yearly economic impact of depression is estimated to be about $100 billion.

It is also the major contributor to the more than 41,000 suicides a year in the US – about one every 13 minutes (about double the number of deaths due to homicide).

What causes depression? According to Mental Health America:

“Many things can contribute to clinical depression.  For some people, a number of factors seem to be involved, while for others a single factor can cause the illness.  Oftentimes, people become depressed for no apparent reason.”

“Biological – People with depression may have too little or too much of certain brain chemicals, called ‘neurotransmitters.’  Changes in these brain chemicals may cause or contribute to depression.”

“Cognitive – People with negative thinking patterns and low self-esteem are more likely to develop clinical depression.”

“Gender – More women experience depression than men. While the reasons for this are still unclear, they may include the hormonal changes women go through during menstruation, pregnancy, childbirth and menopause.  Other reasons may include the stress caused by the multiple responsibilities that women have.”

“Co-occurrence – Depression is more likely to occur along with certain illnesses, such as heart disease, cancer, Parkinson’s disease, diabetes, Alzheimer’s disease, Multiple Sclerosis and hormonal disorders.”

“Medications – Side effects of some medications can bring about depression.”

“Genetic – A family history of depression increases the risk for developing the illness. Some studies also suggest that a combination of genes and environmental factors work together to increase risk for depression.”

“Situational – Difficult life events, including divorce, financial problems or the death of a loved one can contribute to depression.”

However, some of those causes may have to be re-defined after a recent report stating:

“A global consortium of more than 200 scientists identified 44 gene variants, or small changes in genes, each one contributing in some small way to a person’s risk of depression. Thirty of the gene variants had not been identified in any previous study…”

“The massive study, which was published yesterday (April 26) in the journal Nature Genetics, analyzed the genomes of more than 135,000 patients with major depressive disorder, colloquially called major depression, and compared them to the genomes of nearly 350,000 people with no depression.”

“Many of the genes tied to depression also are associated with other psychiatric conditions, such as schizophrenia and bipolar disorder, as well as health issues linked to depression, including obesity and insomnia, the study found.”

“Some of the gene variants control neurotransmitters in the brain, such as dopamine and adrenaline, which the current class of antidepressant drugs can target. Other gene variants have nothing to do with neurotransmitters, though, which may be why antidepressants don’t work for some people if the genetic underpinnings of their depression lie elsewhere in the brain, the scientists said.”

Dr. Steven Hyman, Director of the Stanley Center for Psychiatric Research at the Broad Institute of MIT and Harvard, commented about the study conducted by others, saying:

“Despite decades of effort there have been, until now, only scant insights into its biological mechanisms. This landmark study represents a major step toward elucidating the biological underpinnings of depression.”

The identification of these genes and gene variants will help researchers develop specific drug treatments that should work better than many treatments used today. Many people suffering from depression don’t respond well to some of the main anti-depressants but now that they know what to look for, treatments for various forms of depressions can be more specific and target the real reasons.

The potential of this discovery is huge. Just think of how many suicides could be prevented and how many people could become more productive in life and get off of disability. The future is looking brighter for depression sufferers.