The connection between cortisone and depression is that depression is one of the psychological side effects of steroids such as cortisone. Other psychological side effects are irritability, euphoria and agitation. These effects are particularly evident when high doses of steroids are administered and they may appear within days.
Cortisone and its derivatives are steroids which are effective anti-inflammatory drugs often prescribed for neurological, respiratory, rheumatoid and allergic conditions. While they are a popular and powerful therapy, steroids are associated with both physical and psychological side effects. The link between depression and cortisone as well as the many other mood changes, anxiety, behavioral disturbances and cognitive impairments are little understood and ill defined mainly due to their complexity and unpredictability.
In the past, it was thought that those who suffered from psychological side effects were predisposed to, or already suffering from, a mental disorder such as depression, and cortisone simply exacerbated the condition. More recent studies, however, have shown that this is not so and steroids affect the central nervous system universally. As to why this should vary from a subtle mood change to full-on psychosis is not yet understood. It has been shown that psychological side effects such as euphoria and hypo-mania are more likely with short term treatment and depressive symptoms are more often associated with long term therapy.
The difficulty in studying the connection between cortisone and depression is reflected in the wide variety of study results. While some researchers have found the incidence of steroid-related psychiatric side effects to be under 2%, others have reported the incidence to be over 50%. In an analysis of 11 studies, the average incidence was found to be just under 30%, ranging from mild to severe. Severe psychiatric disturbances was found to average just under 6%. The few studies which have been carried out investigating the response children have to corticosteroids have found that nearly half of those receiving oral cortisone presented adverse psychological effects such as depression and anxiety.
The most significant factor in the connection between cortisone and depression appears to be the dosage. The higher the dosage, the more likely the appearance of side effects with the majority of them occurring early in the therapy. Should cortisone cause mental disorders such as depression, the drug is usually reduced or stopped altogether. However, another link between cortisone and depression is that a rapid or substantial reduction in cortisone may also cause severe changes in mental state. For this reason, care must be taken and the withdrawal closely monitored.