Apolipoprotein D is associated with long-term outcome in patients with schizophrenia

Accumulating evidence implicates deficiencies in apolipoprotein D (ApoD) function and arachidonic acid signaling in schizophrenic disorders. We addressed two hypotheses in relation to ApoD: first, polymorphisms in the ApoD gene confer susceptibility to or are markers of disease, and, second, genetic variation in the ApoD is associated with long-term clinical outcome to antipsychotic treatment. We genotyped two single-nucleotide polymorphisms in the ApoD gene in 343 chronic patients with schizophrenia spectrum disorders (ICD-10) and 346 control subjects of Danish origin. We did not find ApoD alleles, genotypes or haplotypes to be associated with disease. However, we did find that long-term clinical outcome was associated with the ApoD polymorphism rs7659 (P ¼ 0.041) following adjustment for lifetime clinical global impression, age at first admission and gender.