The reduced life expectancy (15-20 years less) often faced by many people with schizophrenia is frequently a result of cardiovascular disease. Lifestyle choices (smoking, lack of exercise and poor diet) can increase the risk of these diseases, but people who take antipsychotic drugs often have the additional problem of weight gain that is caused by the medication.

This systematic review and meta-analysis published in Schizophrenia Research sets out to evaluate the efficacy of non-pharmacological interventions (cognitive behavioural therapy, exercise, changes in diet) for antipsychotic-associated weight gain.

The authors searched for randomised controlled trials (RCT) that aimed to prevent or reduce antipsychotic-associated weight gain by using non-pharmacological interventions (NPI). They found 17 RCTs (8-72 weeks in duration, involving a total of 810 participants):

• 7 RCTs involved cognitive behavioural therapy
• 10 RCTs looked at diet interventions and/or exercise

Here’s what they found:

• Compared to controls, the non-pharmacological interventions (NPI) significantly reduced:
  • Weight gain (14 RCTs, weighted mean difference (WMD) −3.12 kg, 95% CI −4.03 to −2.21, p<0.0001, I2=42%)
  • Body mass index (BMI) (16 RCTs, WMD −0.94 kg/m2, 95% CI −1.45 to −0.43, p=0.0003, I2=75%)
• The authors conducted a sensitivity analyses, which showed that the reductions in weight and BMI were significant in outpatient populations (p<0.0001), but not in inpatient or mixed samples (p values 0.09–0.96)
• At 2-12 months after treatment:
  • The loss of weight was maintained (5 RCTs, n=220, WMD −3.48 kg, 95% CI −6.37 to −0.58, p=0.02)
  • But the BMI benefit was not maintained (5 RCTs, n=211, WMD −0.72 kg/m2, 95% CI −2.36 to +0.58, p=0.40)
• Compared to controls, NPI significantly reduced:
  • Waist circumference (6 RCTs, n=349, WMD −3.58 cm, 95% CI −5.51 to −1.66, p=0.03)
  • Body fat percentage (3 RCTs, n=83, WMD −2.83%, 95% CI −5.35% to −0.30%, p=0.03)
  • Total cholesterol (WMD −20.98 mg/dl, 95% CI −33.78 to −8.19, p=0.0001)
  • Low density-lipoprotein-cholesterol (WMD −22.06 mg/dl, 95% CI −37.80 to −6.32, p=0.006)
  • Triglycerides (WMD −61.68 mg/dl, 95% CI −92.77 to −30.59, p=0.0001)

The reviewers concluded:

Behavioral interventions effectively prevented and reduced antipsychotic-associated weight gain and cardiometabolic perturbations, at least in outpatients agreeing to participate in trials aimed at improving physical health. Effective treatments ranged from nutritional interventions to cognitive behavioral therapy.

These non-pharmacological interventions compare favourably with the drug treatments that would otherwise be offered. It’s interesting to note that diet and exercise changes do as well as CBT, which is good news for financially challenged Trusts who may not be able to afford more expensive talking treatments.

One big downside to the findings is that NPIs were only found to work in outpatient settings and not in the inpatient setting where most antipsychotics are first prescribed and where weight gain often occurs initially. Further studies are needed to explore this issue in more detail.

So this review sets a challenge to professionals working with people who are prescribed antipsychotics. Non-pharmacological interventions can help prevent and reduce weight gain and cardiometabolic risk. The question is: how can we provide these treatments for people in routine practice?

Link

Caemmerer J, Correll CU, Maayan L. Acute and maintenance effects of non-pharmacologic interventions for antipsychotic associated weight gain and metabolic abnormalities: a meta-analytic comparison of randomized controlled trials. Schizophr Res. 2012 Sep;140(1-3):159-68. doi: 10.1016/j.schres.2012.03.017. Epub 2012 Jul 3. [PubMed abstract]