Oswald et al identified a number of risk factors associated with resistance to antidepressant therapy in a patient with depression. These can help identify a patient who may benefit from closer monitoring and more aggressive management. The authors are from multiple university hospitals in Brussels, Austria, France, Isreal and London.


Treatment resistant depression is a failure to respond to consecutive regimens of at least 2 antidepressants in adequate doses.


Risk factors associated with resistance to antidepressant therapy:

(1) severe depression

(2) current suicidal risk (which probably goes along with the severity)

(3) presence of melancholia (which suggests severe depression)

(4) comorbid anxiety disorder

(5) poor response (no response or unsatisfactory response) to initial antidepressant treatment



• Anxiety and depression are often found together. In the implementation I will use severe anxiety as the risk factor. This approach could be expanded to moderate or severe anxiety for greater sensitivity.

• Since treatment resistance is defined as failure to respond to at least 2 different antidepressants, poor response to the first agent used meets part of the criteria.


number of risk factors =

= SUM(number of factors present)



• minimum number of risk factors: 0

• maximum number of risk factors: 5

• The more risk factors present the more likely that the person will be resistant to antidepressant therapy.

• A person who has had an excellent response to the first medication should have a lower risk of treatment resistance.


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