Specific subtypes of abuse sometimes differentiate individuals with BPSD from those with BPSD. Results have found significantly more childhood sexual abuse (Hyun et al. 2000), or more physical abuse but not sexual abuse (Levitan et al. 1998) in adults with bipolar depression compared to unipolar depression. Still others have found relatively higher rates of childhood abuse among adults with unipolar depression (Wexler et al. 1997).