We argue that the treatment of depressive disorders should reject the ‘one size fits all’ model in favour of a model based on a matrix of differing depressive disorders and a more differentiated ‘horses for courses’ management model of treatment. The three-tiered Black Dog Institute hierarchical model for depressive classes lends itself to the development of specific targeted interventions that can be expected to lead to higher rates of treatment efficacy. Further refinements in improving treatment efficacy are also possible by varying the levels or stages of intervention within each of the depressive classes. Varying the type and level of intervention enables treatment to be delivered at a more or less intensive level depending on symptom severity, chronicity, and complexity or comorbidity with other disorders.

The match between patients' and therapists' expectations is crucial for therapy to proceed effectively. A mismatch, unless resolved, becomes a source of distraction and irritation in therapy. Although, if designed by an experienced therapist, such a mismatch can be used to advantage to shift patients' rigid expectations and may be especially useful in treating those with highly dysfunctional personality styles.

Psychological interventions for non-melancholic depression

Recent studies on the treatment of depressive disorders have predominantly focused on pharmacological or other biological therapies, most notably the efficacy of antidepressant medications. Explanations of the origins of depressive symptoms have focused on describing and categorising the various neurotransmitter pathways in the brain that may be responsible for particular physical and/or psychological phenomena.