In a sample of 12 major depressive inpatients, endogenous subtype (8 primary and 4 secondary) defined by Research Diagnostic Criteria, we compared the sensitivity of four potential biological markers: latency of rapid eye movement (REM) sleep (recorded during at least 4 consecutive nights), dexamethasone suppression, and the clonidine and apomorphine tests. Shortened REM latency (less than 50 minutes during at least 1 night) identified 67% of depressives (87% of primary and 25% of secondary); nonsuppression after dexamethasone identified 50% of depressives (62% of primary and 25% of secondary); blunted growth hormone (GH) response after clonidine identified 75% of depressives (100% of primary and 25% of secondary); and blunted GH response after apomorphine identified 42% of depressives (62% of primary and 0% of secondary). Ninety-two percent of patients were correctly identified by at least one biological marker (100% of primary and 75% of secondary depressives). Of 67% of patients positive on at least two biological markers, all were primary depressives (100%). These four biological markers do not necessarily identify the same population, suggesting that their concurrent use may yield the highest level of diagnostic sensitivity.

In a sample of 26 inpatients (15 primary endogenous depressives and a heterogeneous comparison group of 11 psychiatric patients), results of the dexamethasone suppression test (DST) for endogenous depression were compared when cortisol was measured in plasma (total and free) and in saliva. Results showed a close linear relationship among plasma total and free cortisol, plasma total cortisol, and saliva cortisol, and between free plasma and saliva cortisol. A saliva cortisol cutoff point of 70 ng/dl achieved the same sensitivity (67%), specificity (91%), and diagnostic confidence (91%) as the best cutoff scores of plasma total cortisol (5 micrograms/dl) and plasma free cortisol (0.15 microgram/dl). These results suggest that saliva cortisol, which directly reflects the biologically active fraction of cortisol, can be used as a reliable and more practical index in the DST, especially in outpatients.

Clinical differences exist between the benzodiazepines but demonstration of such differences requires a more specialized methodology than that normally used in comparative trials. It is recommended that double-blind studies should be carried out in hospitalized patients with severe and chronic anxiety, selected according to precise criteria, and that the trials should be designed as crossover rather than as parallel group studies, with randomization of the stages and flexible dosage. A simple graphic method of representing the clinical profile of individual benzodiazepines is described and it is suggested that this could help clinicians adapt their prescribing to each patient's symptoms.

The anxiolytic activity of methylclonazepam was compared to lorazepam and placebo in a double-blind, randomized cross-over study, using a latin square design, in 18 inpatients meeting Research Diagnostic Criteria for Generalized Anxiety Disorders. Patients presented at least 1 year of symptomatology and had a minimum score of 20 on the Hamilton Anxiety Scale, despite chronic anxiolytic pharmacotherapy. Daily dosage was flexible, from three to six tablets of methylclonazepam 1 mg, lorazepam 2.5 mg, or placebo. Clinical evaluation included Hamilton Anxiety Scale, Clinical Global Impression (CGI), a side-effects checklist, completed every 2 days, and the global preference of the patient for one of the treatment periods. Results showed a highly significant superiority of both benzodiazepines over placebo on the Hamilton Scale (P less than 0.000001) and CGI (P less than 0.001), and also a significant superiority of methylclonazepam over lorazepam on the Hamilton Scale (P less than 0.01), CGI-1 (P less than 0.01), and in the number of patient preferences (14 versus 1; P less than 0.001), with no significant differences in side-effects or related to position in the trial. These results support the value of the cross-over design in chronic and severe anxious inpatients for the demonstration of differences in efficacy between anxiolytic pharmacotherapies.

A new formulation of oxazepam especially designed to increase the speed of absorption and eliminate the need to use water (freeze-dried dosage formulation; FDDF) was compared in double-blind and crossover conditions with the standard tablets of the same compound. 5 inpatients with generalized anxiety disorder received at 1-week intervals a single 30 mg dose of one of the compounds. Every 8 min for 96 min after drug intake, they completed a battery of visual analogue scales and had an EEG recording with computerized spectral analysis. Results showed a significantly more rapid onset of activity of FDDF oxazepam for both the self-reports of anxiety level (p < 0.005) and the specific β₂ EEG changes (p < 0.0001), which were significantly correlated (r = -0.73; p < 0.01). Moreover, all patients rated FDDF oxazepam as having faster onset of action in clinical change than regular tablets (p < 0.05). This study shows the value of visual analogue scales, pharmaco-EEG, and crossover design in well-selected anxious inpatients in substantiating clinical differences between anxiolytic pharmacotherapies.