Putting aside the discussion on the effectiveness of one psychotherapeutic approach over another, it is clear that the differences in approaches appears to be minimal or small at the very least (Wampold,2001,2007,2010). And so we are left with the question: if the differences in effectiveness of approaches is minimal what are the other factors that influence the outcome of psychotherapy? On reviewing the evidence, Lambert & Bergin, (1994) firmly state that common factors account for positive outcomes in therapy and may be credited with “the gains that result from psychological interventions” (McFadzean, 2005).
Norcross (2005b, p. 9) in describing the common factors approach states: “The common factors approach seeks to determine the core ingredients that different therapies share in common, with the eventual goal of creating more parsimonious and efficacious treatments based…show more content… Drawing on years of experience Lambert (1992) proposed four common therapeutic factors. (Assay and Lambert,1999 ;, Hubble et al.,1999a;, McFadzean, 1995). In his 1992 paper Lambert suggested that nearly 40 % of the improvement in psychotherapy is from client variables or extra-therapeutic events, which would include everything about the client and their environment e.g. personality, history, motivation, social support; an estimated 30 % improvement was attributed to the therapeutic relationship or therapeutic alliance including for example, empathy, warmth & trust; a further 15% was associated with placebo and expectancy effects and finally 15% of the variables attributed to the therapist’s specific techniques or approach. Lambert, (1992) Assay and Lambert, (1999), Hubble et al., (1999a) McFadzean, (1995) interestingly only 15% of the outcome of therapy is attributed to approach or therapeutic technique. Cooper, (2008).
Figure 1,‘Lambert’s Pie’: shows graphically how common factors are estimated to contribute to client improvement.