The Science Behind Depression: Why Your Mind Constantly Finds Reasons to be Depressed3 min read

There is no single reason why someone might experience anxiety or depression. Sometimes you may feel depressed without there being a clear reason why—it’s almost as if you’re waiting for a reason to be upset. 

The truth is depression is related to a mixture of social, environmental and biological factors. For some, depression sets in after a difficult life event. For others, depression is a constant threat to their state of mind, and that’s down to certain biological factors:

Genes

Every part of the body, including the brain, is controlled by genes that influence our biological functioning and response. Scientists have identified many neurotransmitters that impact how your brain regulates your mood. There is a sizeable amount of evidence suggesting people can be genetically vulnerable to anxiety and other mental illnesses.

Trauma

Not dealing with past trauma can take its toll on mental health, and subconsciously affect how we respond to life’s difficult moments. Research shows past trauma negatively affects the functioning of the CRH and the HPA axis. The HPA axis is located in the brain and plays a key role in coordinating our emotional reactions, thoughts, behaviors and involuntary responses. CRH is a cortisol-releasing hormone that triggers the body’s fight or flight defenses when a threat is sensed. These imbalances can make symptoms of anxiety and depression more pronounced.

Brain chemical imbalance not quite

It may come as a shock to many but ‘brain chemical imbalance’ is no more than a figure of speech. Commonly cited as cause for anxiety and depression, this theory is disputed within the medical community.

The notion that mental illnesses, specifically depression and anxiety, are caused by chemical imbalances of the brain was first proposed in the 1950s by scientists. To this day, the theory is unproven. Millions of chemical reactions are happening in the brain at any given moment. There’s no simple way to tell which chemicals are out of balance or impacting someone’s feelings. 

Stress

Medical experts have found evidence that stress suppresses the production of new nerve cells in the hippocampus area of the brain. This is where long term memory and fear is registered.

 

To Keep learning visit Harvard Medical School.