A review of the published case reports of adverse behavioral episodes or unexpected psychopathology in patients taking benzodiazepines was undertaken in an attempt to determine if these adverse or unexpected events are more likely to occur with alprazolam when compared with other currently marketed benzodiazepines. Adverse behavioral phenomena and unexpected psychopathology were divided into the following categories: (1) anger or violence, (2) impulsive, suicidal, or self-harming behavior, (3) depression, (4) mania, (5) schizophrenia, (6) withdrawal syndromes and (7) physical dependence and abuse liability. It is difficult to draw conclusions from this literature because of the limitations of spontaneously reported cases and the lack of epidemiologic studies. Despite these limitations, it appears that some differences between alprazolam and older benzodiazepines may exist. The older benzodiazepines are more commonly reported to have adverse events than alprazolam (with the exception of mania or hypomania). On the other hand, worsening in post-traumatic stress disorder and an increase in impulsive behavior in patients with borderline personality disorder have only been reported in patients receiving alprazolam. This is probably explained by the fact that only alprazolam has been used to any great extent in these conditions.