Effects of Antipsychotics on Eating and Food Craving in People With Schizophrenia

Objective

Some second-generation antipsychotics, such as olanzapine and clozapine, seem especially prone to induce metabolic complications and substantial increases in weight. The mechanisms of these side effects are unknown, but may include antagonism at histamine H1 receptors. We will refer to olanzapine and clozapine as antipsychotics with a high weight-gain liability (HWGL). The primary aim of this project is to examine eating and food craving in patients with schizophrenia who are taking HWGL antipsychotics compared with those taking LWGL antipsychotics (mid- to high-potency first-generation antipsychotics, aripiprazole, or ziparasidone) and compared with healthy controls taking no antipsychotics. The antipsychotics we are classifying as LWGL group do not have appreciable H1 receptor antagonism. We will exclude participants taking antipsychotics that have middling degrees of H1 receptor antagonism (e.g. quetiapine).

This study will help us understand how people with schizophrenia differ from controls on eating and food craving, as well as the effects of different classes of antipsychotics. This knowledge should help to guide practitioners when advising patients about the weight-gain effects of these medications. For example, if we find that participants on HWGL antipsychotics tend to crave high-fat foods, practitioners can work with patients to anticipate and mitigate this side effect.

Study population. The study population will be in- or outpatients with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder stabilized on either olanzapine or clozapine (HWGL antipsychotics) (N=20), aripiprazole, ziprasidone, or a first-generation antipsychotic (LWGL antipsychotics) (n=20), and normal controls (people with no Axis I psychiatric disorder taking no antipsychotic medication) (n=20), for a total of 60 participants. All participants will be between the ages of 18 to 45 years and considered overweight (BMI greater than or equal to 25 and less than or equal to 29.9 kg/m(SqrRoot)). The pediatric population has been excluded to rule out certain hormonal effects (e.g. puberty) on eating behavior. A BMI range encompassing participants that are overweight was selected to maximize recruitment and to minimize confounding effects of BMI on eating behavior. Exclusion criteria will include weight-related conditions and current dietary restrictions.

Experimental design and methods. In a between-subjects design, the three study groups will be compared in terms of four domains of eating behavior: (1) food craving, (2) satiety signaling, (3) meal size (satiation), and (4) food preferences. Assessments will occur during five study visits (including an initial visit for consenting and screening).

Outcome measures: Primary outcome measures will include a preload-test meal paradigm (satiety), meal size perception and satiation, food preference, food craving, and gustatory functioning. Secondary measures will include: Weight and Eating Assessment questionnaire, Recent Physical Activity Questionnaire (RPAQ), State Trait Anxiety Inventory (STAI), Exercise Motivations Inventory (EMI), Childhood Trauma Questionnaire, Tobacco Craving Questionnaire-Short Form (TCQ-SF), Fagerstrom Test for Nicotine Dependence (FTND), BMI, hip/waist measurements, and fasting blood work: CBC, CMP14, lipid panel, leptin, ghrelin, adiponectin, and thyroid panel.