Chronic diazepam treatment in psychiatric outpatients.

Anxiety symptoms and plasma diazepam and desmethyldiazepam were assessed in 50 male outpatient veterans with primary chronic anxiety symptoms who had been taking an average of 17.7 mg of diazepam per day for a mean of 4.9 years. These subjects were moderately anxious (mean Hamilton Anxiety Scale score = 23) despite their chronic diazepam use. Although tolerance could explain this inadequate anxiolytic effect, the absence of a significant correlation between duration of use and either diazepam dose or any of the three anxiety measures argues against this hypothesis. The findings of modest diazepam dose and plasma concentration (mean=324 ng/ml) and of a trend toward a positive correlation between anxiety level and both dose and plasma level suggest inadequate dosage as a more likely explanation for the subjects' continued anxiety.