Evaluation of a Cognitive Therapy (Inference-based-therapy) for the Treatment of Obsessional Compulsive Disorder
Condition: Obsessive Compulsive Disorder
MeSH terms: Compulsive Personality Disorder; Obsessive-Compulsive Disorder
Study type: Interventional

Summary: 
      Obsessional compulsive disorder (OCD) is a very debilitating psychiatric problem which
      affects around one million Canadians and their families. Obsessions are intense
      preoccupations about bad, harmful, dangerous, shocking or unlucky events which 'may' occur
      and which drive sufferers to perform time consuming and distressing compulsive rituals to
      prevent the possible event occurring. The current psychological treatment of choice is
      cognitive behavior (CBT) therapy which focuses on treating OCD by reducing obsessional
      anxiety about the likelihood and the consequences of the preoccupying event. A rival
      cognitive model termed the inference-based therapy (IBT), developed by the principal
      investigator and co-workers, considers that the OCD begins with the initial doubting
      inference 'maybe something is wrong' and focuses on changing the reasoning behind this
      doubting inference which often trumps the common sense conviction that there is no reason to
      doubt. This clinical trial randomly allocates participants to either IBT or CBT treatment
      condition or to a third generic mindfulness condition. The latter condition is a non-specific
      meditational-based training which has shown evidence of reducing stress and anxiety across a
      number of psychiatric problems including OCD. Two hundred and forty people will be recruited
      over a 5-year period from two principal sites (Montreal and Gatineau/Ottawa) with which the
      principal investigator and co-investigators have clinical links. Therapy will be administered
      by trained professionals following a treatment manual specific to each approach. The therapy
      will last a maximum of six months or until the point when the person achieves a non-clinical
      status. The patients will be assessed pre, post, and at six months following treatment on
      standard evaluation instruments as well as on subjective measures. We expect the IBT to be
      superior in terms of number of participants responding to treatment, rapidity of improvement
      and gains at follow-up.
    

Detailed description: 
      Obsessive compulsive disorder (OCD) affects 1-3% of the population and is the fourth most
      common mental disorder. It is characterized by a preoccupying obsessional doubt that harm,
      illness, disorder or bad luck, will occur if compulsive actions are not carried out to
      neutralize the risk. Treatments of choice include pharmacotherapy and cognitive behavior
      therapy (CBT) either alone or in combination. Although these interventions are clinically
      effective, they usually do not reduce the obsessions to a sub-clinical level. There is a risk
      of relapse and even so a sizeable minority of people with OCD refuse or abandon treatment,
      and some specific subtypes of OCD show no or minimal response. CBT-as-usual, involves
      principally the administration of exposure and response prevention (E/RP). A cognitive
      psycho-education element may by added in line with current cognitive thinking that it is the
      appraisal the person attributes to the initial intrusive thought with engenders obsessional
      distress. Such cognitive treatment will focus on modifying the anxiety and beliefs about
      consequences following on from the initial obsessional preoccupation. A competing cognitive
      model termed the inference-based approach (IBA) developed by the principal investigator and
      co-workers offers an account of obsessions which focuses on the reasoning producing the
      initial obsessional doubt as the source of the OCD. In this model the obsessing begins at the
      point where the person crosses over from reality into the initial obsessional doubt since the
      doubt is not based on real perception but on a subjective narrative misleading the person to
      infer doubt where no doubt is required. Over the last 10 years, experimental, clinical and
      psychometric research studies (independently replicated) have supported the essential claims
      of the IBA and have led to development of inference-based therapy (IBT). A small scale
      randomized clinical trial, and clinical case studies have established IBT as a 'promising'
      intervention (according to American Psychological Association criteria) and shown that IBT
      seems to offer advantages over conventional CBT, particularly for treatment-resistant cases
      who over-invest in their obsessional convictions. The current randomized clinical trial will
      compare IBT to CBT as usual, and to a third active control condition of mindfulness.
      Mindfulness is a generic treatment shown effective in a range of psychiatric problems which
      seeks to calm thoughts by redirecting mental focus through meditative distancing. The
      mindfulness condition is a non-specific cognitive control for any confounding effect of mood
      change on symptom relief. CBT follows an 'appraisal' model either through restructuring
      appraisals and beliefs about the obsession or by de-dramatizing anxious expectations through
      exposure and reality testing (combined with E/RP). IBT seeks to change the reasoning leading
      up to the initial inference of doubt on the principle that eliminating the doubt logically
      and necessarily eliminates all anticipated consequences and accompanying obsessional anxiety.
      All three treatments will be manualized and administered by experienced professional
      therapists supervised by a co-investigator with an allegiance to one of the three approaches.
      The three treatment models operate on distinct processes and on separable stages of the
      obsessional chain, so therapy components will not overlap. The principal sites chosen will be
      Montreal Louis-H. Lafontaine Hospital and Gatineau Pierre-Janet Hospital. A total of 80
      participants will be recruited over a five-year period into each treatment modality, giving a
      total of 240, which will permit robust conclusions even with weak effect sizes. Outcome
      evaluators will be blind to treatment modality and independent of therapists. All therapy
      will be delivered on an individual weekly basis until significant clinical improvement or up
      to a maximum of 26 weeks with a 6-month follow-up post-treatment. All parameters of treatment
      delivery will be identical across treatments. All sessions will be audio recorded and
      treatment integrity will be rated independently. Outcome measures will be standard DSM-IV
      based clinical diagnostic scales and also psychosocial measures of end-point functioning
      across life domains. Treatment process variables will be continuously monitored. Refusal and
      attrition are calculated at 16% and analysis will include intention to treat. The hypotheses
      are that: (1) all treatments will be effective in improving mood and reducing symptoms; (2)
      the IBT will be superior in terms of: (a) its consistent impact over all types of OCD; (b)
      its lower rate of relapse. The RCT will be the first of its kind in comparing these three
      active treatments and will impact on treatment of choice for OCD.
    

Intervention name(s): Cognitive behavior therapy; Mindfulness-based stress reduction; Inference-based therapy
Intervention type(s): Behavioral; Behavioral; Behavioral
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Inference-based therapy; Cognitive behavior therapy; Obsessive compulsive disorder; Randomized clinical trial