Anxiety and depression almost always go together. It is not uncommon for someone suffering from an anxiety disorder to also experience depression. Research shows that depressive disorders frequently co-occur with anxiety disorders. According to the largest survey taken in the United States, called the National Comorbidity Survey, more than half of patients diagnosed with major depressive disorder (MDD) have also had an anxiety disorder.

Which Comes First?

Anxiety and depression both share overlapping symptoms, incidence/risk factors, genetic/biological markers and similar treatment methods. The problem many research studies are still trying to understand is the nature of the relationship between anxiety and depression. In some patients these two disorders occur at the same time while in other patients, anxiety precedes the depression by several years, or vice versa.

When anxiety precedes depression, it may cause what is called secondary depression. Other times, depression comes first and then when people recover from depression they feel anxious. Depression can often be tainted by a negative stigma, which in turn can exacerbate anxiety. Organizations such as iFred help educate on this negative stigma, lessening its affects. On other occasions, anxiety can be caused as a direct result from treatment for depression such as antidepressants or from administration of benzodiazepines or tranquilizers.

Similar, but Different

People with medical illnesses frequently have anxiety and depression simultaneously. Some patients cannot distinguish and properly explain whether they experience anxiety or depression. Yet, a new classification recently published by American Psychiatric Association refused to grant the Mixed Anxiety Depression (MAD) syndrome a separate diagnostic status even though MAD exists in the International Classification. The relationship between anxiety and depression can be rather complicated.

Over the years researchers made many attempts to clarify the relationship between anxiety and depression and attempted to distinguish them. Two recent studies have attempted to explain why anxiety and depressive disorders commonly coexist and examine the risk factors associated with them.

Unified Research on Mixed Diagnosis

The research on anxiety and depressive studies increases our knowledge about the relationship between anxiety and depression, but still remains unclear. The researchers in recent studies seem to think that anxiety and depression are two distinct entities that overlap in terms of symptoms and time of occurrence. They agree with DSM-5 on non-inclusion of a mixed diagnosis of anxiety and depression. In other words, they agree that anxiety and depression are two separate disorders that have some overlap rather than two variations on one problem.

New research has also shown that there are distinct differences in the incidences and risk factors associated with the anxiety and depressive disorders. Further studies addressing underlying mechanisms of these syndromes could provide more insight into why anxiety and depression disorders are connected. This knowledge may improve our understanding and treatment of these important conditions.

More on the Studies

One of these supporting studies, published in April 2013, investigated overlapping symptoms associated with Generalized Anxiety Disorder (GAD) and Major Depressive Disorder (MDD) as they occurred in primary care. The two disorders share many of the same symptoms such as fatigue, sleep disturbances, restlessness, and problems concentrating.

The aim of the study was to examine if the coexistence of anxiety and depressive disorders could be explained by an overlap in diagnostic criteria. The study enrolled 1,218 participants who had either GAD, MDD, or both GAD/MDD. Each patient then participated in a structured interview processes that assessed for various mental disorders.

A second study investigated the incidence and risk patterns for anxiety and depressive disorders by interviewing 3021 adolescents and young adults in Munich Germany. The researchers gathered each individual's family history, surveys from their parents, and a series of follow-up surveys for 10 years after the initial interview. They then measured the incidences of various anxiety disorders (including GAD) as well as depressive disorders and their rate of coexistence among the sampled participants.

Results and Outlook

The results from the first study revealed that the patients who suffered from both GAD/MDD experienced more of the overlapping symptoms for anxiety and depression rather than the non-overlapping symptoms. Similarly, these patients experienced the overlapping symptoms of anxiety and depression more than the patients who suffered from just GAD or MDD alone. These findings suggest that the coexistence of GAD and MDD may be a result of overlapping symptoms.

The second study found a strong association between anxiety and depression, too. However, the results revealed that the association between GAD and other anxiety disorders was stronger than the association between anxiety and depressive disorders. Also, they found that GAD differed from other anxiety and depressive disorders in regard to family history and personality characteristics.

Analysis of the data showed that there were many differences among the patterns for GAD, other anxiety disorders, and depressive disorders. The authors concluded that anxiety and depressive disorders are remarkably different with distinctive risks, patterns, and familial association.

There is still research that needs to be done to explain why the coexistence of anxiety and depression is such a common occurrence. This phenomenon is typically attributed to the lack of diagnostic clarity as well as corresponding pharmaceutical options for treatment. Nonetheless, there may be good news: current psychiatric treatments are mostly symptomatic. Regardless of the diagnosis, both anxiety and depression seem to respond to similar medications (mostly antidepressant agents).

Date of original publication:
Updated on: January 03, 2016