An approach to treatment-resistant depressionDefinition:Failure to respond to adequate (dose and duration i.e. max. dose for at least 6weeks) courses of 2 antidepressants, or 1 antidepressant and ECT.The consequences of resistant depression include: 1) Reduced quality of life. 2) Excessive strain on relationships (which may lead to break-up of families). 3) Significant personal economic impact. 4) Increased physical comorbidity (e.g. malignancy, cardiovascular disease, even premature death). 5) Increased risk of suicide. 6) Therapeutic alienation (making further interventions difficult due to difficulties forming a therapeutic alliance). 7) High use of psychiatric services (without clear benefit).Differentiating "treatment resistance":It is important to distinguish actual treatment resistance from chronicity ofsymptoms.Apparent treatment failure may also occur due to: 1. Incorrect initial diagnosis (i.e. not depressive disorder). 2. Inadequate initial treatment. 3. Poor compliance. 4. Incomplete formulation (esp. role of maintaining factors). 5. Comorbidity (both physical and other psychiatric disorders).
Risk factors for treatment resistance: o Concurrent physical illness. o Drug/alcohol abuse. o Personality disorder. o Delayed treatment. o High premorbid neuroticism.Management: i. Review diagnostic formulation: Is diagnosis correct?, Are there any unaddressed maintaining factors (e.g. social, physical, psychological)? ii. Check patient understanding and compliance: (serum levels may help). iii. Continue monotherapy at maximum tolerable dose: May mean exceeding dose guidelines (esp. if there has been partial benefit). iv. Consider change in antidepressant: Try a different class of antidepressant. v. Consider augmentation with a mood stabiliser: (e.g. lithium). vi. Consider additional augmentative agents: (e.g. L-tryptophan, T3).vii. Consider combining antidepressants from different classes: Caution is advised, due to possible serious adverse reactions (e.g. serotonin syndrome).viii. Consider use of ECT: (esp. if severe biological features or psychotic symptoms). ix. Consider possibility of psychosurgery.