The co-existence of anxiety and depression
Anxiety and depression frequently co-concur - clients often present with both mental states at the same time; often one tends to be more pronounced then the other and there is fluidity. Your anxiety may be more troubling one day than your depression and vice versa. Vulnerability factors that contribute to a diagnosis of anxiety-depression comorbidity (that is a diagnosis of more than one health problem) include childhood trauma, a family history of depression and anxiety, negative life events and personality traits.
There is often a chicken and egg situation with anxiety and depression. For example having anxious thoughts and constant worries will affect your mood and can lead to a sense of helplessness or hopelessness often associated with depression. Conversely experiencing deeply troubling thoughts when in the grip of a depressive episode can lead to a constant worry and fear of the next episode.
The prevalence of both anxiety and depressive disorders is very high: one study ranked major depression as fourth on the global list of most disabling illnesses in the world population. Anxiety comes very close on the heel on this list. Over half of all patients who have been diagnosed with a type of anxiety also have depression. There are a range of different types of anxiety disorders for example generalised anxiety disorder (GAD), health anxiety, obsessive-compulsive disorder (OCD) or post-traumatic stress disorder (PTSD).
When a client is diagnosed with depression the likelihood that they will suffer from anxiety is very high. By the same token, a client with anxiety disorder is likely to also display depressive symptoms. Frequently life stressors such as the loss of a loved one or interpersonal conflict lead to clinical levels of anxiety which in turn makes a further decline into depression more likely. With both conditions there is often a feeling of no hope and helplessness.
Often one condition masks the other, thus a diagnosis of depression may overlook that the client also suffers from clinical anxiety. In part this is explained by the similarity in symptoms of both disorders. Thus an anxious client may suffer from insomnia or a loss of appetite as does a depressive client.
Anxiety and depression can often reinforce each other. Being able to recognise that you suffer from more than one problem helps you to have to a better understanding your experiences and reactions, what causes them and how they may be best addressed.
References
Understanding comorbid depression and anxiety. Psychiatric times. http://www.psychiatrictimes.com/articles/understanding-comorbid-depression-and-anxiety
Loewe, B, Spitzer RL, Williams JB, Mussell M, Schellberg D, Kroenke K: Depression, anxiety and somatization in primary care: syndrome overlap and functional impairment. Gen Hosp Psychiatry. 2008 May-Jun;30(3):191-9.
Lamers F1, van Oppen P, Comijs HC, Smit JH, Spinhoven P, van Balkom AJ, Nolen WA, Zitman FG, Beekman AT, Penninx BW. Comorbidity patterns of anxiety and depressive disorders in a large cohort study: the Netherlands Study of Depression and Anxiety (NESDA). J Clin Psychiatry. 2011 Mar;72(3):34