Association between antipsychotics and body mass index when treating patients with tics

Treatment with antipsychotics can be associated with weight gain, and second-generation (atypical) antipsychotics (SGAs) can increase the risk for diabetes and dyslipidemia. These risks have not been assessed in patients with tics, who receive lower doses than those used to treat psychosis. The objective of this study is to investigate the relationship between antipsychotic use and weight in tic patients and compare the effects of SGAs to first-generation (typical) antipsychotics (FGAs).

We studied the association between antipsychotic use and body mass index (BMI) in consecutive patients with tics seen in a specialty Movement Disorders clinic.

Height and weight were recorded on 198 patients, average age 19.9 years+/-14.0 years, 128 treated and 70 not treated with antipsychotics. Standardized measures of BMI were significantly higher in the antipsychotic-treated patients compared to the untreated patients (0.56+/-1.10) treated vs. untreated (-0.31+/-0.82). This difference remained significant after controlling for age, gender, stimulant medications, and co-morbidities such as attention-deficit/hyperactivity disorder (ADHD) and obsessive compulsive disorder (OCD). Concomitant medications did not independently influence weight, and there was no difference between FGAs and SGAs. Antipsychotic dose, expressed in chlorpromazine (CPZ) equivalents, and treatment duration did not influence weight.

Patients with tics on either FGAs or SGAs have higher BMI values compared to patients on no antipsychotics. Better knowledge of this risk should guide physician decision making when treating patients with tics.