Fragile X syndrome (FXS) is a model for studying the relative contributions of genetic and environmental factors to psychiatric disorders in mothers of children with disabilities. Here, we examine the frequency and predictors of mood and anxiety disorders in mothers with the FMR1 premutation. Ninety-three females with the FMR1 premutation were in the study and were compared to 2,159 women from the National Comorbidity Survey Replication (NCS-R) dataset. Mood and anxiety disorders were assessed using the SCID-I. Our data reflect elevated lifetime major depressive disorder (MDD), lifetime panic disorder without agoraphobia and current agoraphobia without panic disorder in the FMR1 premutation sample. Also, we found a low frequency of lifetime social phobia, specific phobia, and post-traumatic stress disorders and current specific phobia in the FMR1 premutation sample. The profile of MDD in the FMR1 premutation sample was not episodic or comorbid with an anxiety disorder, as in the NCS-R dataset. Never having been married and smaller CGG repeat length were associated with increased likelihood of MDD while increased children with FXS in the family and greater child problem behaviors were associated with increased likelihood of an anxiety disorder in the FMR 1 premutation group. Major depression in females with the FMR1 premutation may not be characterized as an episodically chronic recurrent disorder as it is in community samples and may have a genetic basis given the relationship with CGG repeat length and lack of association with all child and most demographic factors. © 2008 Wiley-Liss, Inc.