A pilot randomized clinical trial evaluating the impact of genetic counseling for serious mental illnesses

The serious mental illnesses schizophrenia, schizoaffective disorder, and bipolar disorder are complex conditions affecting 1% to 4% of the population. Individuals with serious mental illnesses express interest in genetic counseling, an intervention showing promise for increasing patient knowledge and adaptation. This trial aimed to evaluate the effects of genetic counseling for people with serious mental illnesses as compared to an educational intervention or wait list.

A pilot 3-arm (each n = 40; genetic counseling, a control intervention involving an educational booklet, or wait list), parallel-group, randomized clinical trial was conducted from September 2008 through November 2011 in Vancouver, Canada. Participants with schizophrenia, bipolar disorder, or schizoaffective disorder (DSM-IV) completed outcome measures assessing knowledge, risk perception, internalized stigma, and perceived control over illness at baseline and 1-month follow-up. The Brief Symptom Inventory was administered to control for current symptoms. Analyses included linear mixed-effects models and χ(2) tests.

Knowledge increased for genetic counseling/educational booklet compared to wait list at follow-up (LRT1 = 19.33, Holm-adjusted P = .0003, R(2)LMM(m) = 0.17). Risk perception accuracy increased at follow-up for genetic counseling compared to wait list (Yates continuity corrected χ(2)1 = 9.1, Bonferroni P = .003) and educational booklet (Yates continuity corrected χ(2)1 = 8.2, Bonferroni P = .004). There were no significant differences between groups for stigma or perceived control scores.

Genetic counseling and the educational booklet improved knowledge, and genetic counseling, but not the educational booklet, improved risk perception accuracy for this population. The impact of genetic counseling on internalized stigma and perceived control is worth further investigation. Genetic counseling should be considered for patients with serious mental illnesses.

ClinicalTrials.gov identifier: NCT00713804.