How the intervention might work
Cognitive behavioural therapy aims to remediate distressing emotional experiences or dysfunctional behaviour by changing the way in which the individual interprets and evaluates the experience or cognates on its consequence and meaning. Cognitive behavioural therapy encourages the person to identify and challenge biased interpretations of experiences that may be maintaining symptoms. Many of the CBT programmes (e.g. Garety 2008) are based upon a stress-vulnerability model of symptom onset and relapse. The empirical evidence for the stress-vulnerability model has been questioned (McKenna 2007).
In a recent theoretical review of the potential change processes that CBT for psychosis might possess, Birchwood 2006 distinguishes between "quasi-neuroleptic" effects of CBT upon psychotic symptoms (e.g., hallucination) and the emotional and behavioural consequences of such experiences or their treatment. Accordingly, Birchwood 2006 distinguishes between emotional/behavioural distress and psychotic symptomatology and advocates the former as an appropriate target for CBT interventions. Specifically, Birchwood 2006 suggests that CBT might focus upon the following.
1. Distress reduction or the reduction of depression and problem behaviour associated with beliefs about psychotic symptomatology.
2. The emotional and interpersonal difficulty in individuals at high risk of developing psychosis.
3. Relapse prodromes to prevent relapse in psychosis.
4. ‘Comorbid’ depression and social anxiety, including the patient’s appraisal of the diagnosis and its stigmatising consequences.
5. General stress reactivity, thereby increasing resilience to life stress and preventing psychotic relapse.
6. Increasing self-esteem and social confidence in people with psychosis.
However, many of the current trials of CBT for psychosis have defined their outcomes in terms of psychotic symptomatology (e.g., hallucinatory and delusional experience) rather than distress, problem behaviour or stigma and self esteem.