ORGANUM
Despite a larger number of antidepressants available, they are far from ideal. Clinicians have thus devised combination and augmentation strategies, particularly in use with SSRIs, to try and achieve improvement in depressive symptoms. Two-thirds of depressed patients will respond at some extent albeit it after 2-8 weeks.
Response to pharmacological therapy in depression is defined as at least a 50% reduction in depressive symptoms evaluated in a standardised methods; Hamilton Depression rating scale (HAM-D) or Montgomery-Asberg depression scale. If there is poor response to monotherapy, a few strategies can be employed:
Combination : Two or more antidepressants combined together
Augmentation : Addition of a non-antidepressant therapy to a particularly active therapy.
Some combination of antidepressants can be very dangerous and thus should be avoided - for example, the use of an SSRI, SNRI or TCA with MAOI.
The following information is adapted from NICE Guideline 222 (NG222):
First line
Addition of Mirtazapine (Alpha-2-adrenoceptor antagonist) or Trazodone (Serotonin antagonist & reuptake inhibitor, SARI).
Second line
Addition of Lithium therapy
Third line
Addition of atypical/second generation antipsychotic therapy:
Aripiprazole
Olanzapine
Quetiapine
Risperidone0