Lupus autoantibody levels correlate with depression behavior. Linear regression correlation of % floating time in forced swim test with serum anti-dsDNA titers (A, 8w; D, 18w), anti-NMDAR antibody titers (B, 8w; E, 18w), or anti-cardiolipin antibody titers (C, 8w; F, 18w) were shown. MRL/+: ■, MRL/lpr: ▼. P values and Pearson’s R values for each correlation are also shown in the graphs.