A multicenter, double-blind comparison of the effects of nefazodone and fluoxetine on sleep architecture and quality of sleep in depressed outpatients

This study was an 8-week, randomized, double-blind, parallel-group investigation that compared the effects of nefazodone and fluoxetine on sleep architecture and on clinician- and patient-rated sleep measures in 43 outpatients with moderate to severe, nonpsychotic major depressive disorder and insomnia. Twenty-two patients received nefazodone 200 mg daily for 1 week, followed by 400 mg daily for 7 weeks. Twenty-one patients received fluoxetine 20 mg daily. Dosage increases (to 500 mg/day for nefazodone and 40 mg/day for fluoxetine) were available after day 29, depending on clinician judgement. Sleep parameters were measured during baseline phase, while patients were unmeasured and symptomatic, and at weeks 2, 4, and 8 of treatment. Nefazodone and fluoxetine were equally effective as antidepressants. However, compared with baseline, nefazodone increased sleep efficiency and reduced the number of awakenings and percent awake and movement time, whereas fluoxetine increased the number of awakenings and did not significantly alter sleep efficiency or percent awake and movement time. Although fluoxetine increased stage 1 sleep and rapid eye movement (REM) latency and reduced total percent REM sleep, nefazodone increased REM sleep, decreased REM latency, and did not alter stage 1 sleep. Differences between treatment groups, based on change from baseline, revealed greater sleep efficiency, fewer awakenings, less percent awake and movement time, less percent stage 1 and more REM sleep, and shorter REM latency for nefazodone compared with fluoxetine. Significantly greater improvement in clinician- and patient-rated sleep disturbance was found with nefazodone compared with fluoxetine. Nefazodone was associated with better sleep quality.

Double-blind comparison of sertraline, imipramine, and placebo in the treatment of dysthymia: psychosocial outcomes

OBJECTIVE

The purpose of this study was to determine the effects of antidepressant pharmacotherapy on mood symptoms and psychosocial outcomes in dysthymia.

METHOD

In a multicenter, double-blind, parallel-group trial, 416 patients with a diagnosis of early-onset primary dysthymia (DSM-III-R) of at least 5 years' duration without concurrent major depression were randomly assigned to 12 weeks of acute-phase therapy with sertraline, imipramine, or placebo. The psychosocial outcome measures used in the study were the Global Assessment of Functioning Scale, the Social Adjustment Scale, the Longitudinal Interval Follow-up Evaluation psychosocial ratings, and the Quality of Life Enjoyment and Satisfaction Questionnaire.

RESULTS

Sertraline and imipramine were significantly better than placebo in improving psychosocial outcomes as measured by the first three instruments. The Quality of Life Enjoyment and Satisfaction Questionnaire scores demonstrated significant improvements from baseline, and both active treatments produced significantly greater improvements than placebo. Significantly fewer patients discontinued sertraline (6.0%) than discontinued imipramine (18.4%) because of adverse events.

CONCLUSIONS

Pharmacotherapy is an effective treatment for dysthymia in terms of psychosocial functioning as well as depressive symptoms, even when the dysthymia is long-standing.

The infrequency of "pure culture" diagnoses among the anxiety disorders

BACKGROUND

Anxiety disorders are known to commonly coexist in individuals, both with other anxiety disorders and with mental disorders from other groupings, such as affective disorders. We questioned how frequently anxiety disorders actually occur in isolation, as "pure cultures."

METHOD

We examined diagnostic patterns among the 711 subjects entered into a large, multicenter study of anxiety disorders, the Harvard/ Brown Anxiety Disorders Research Program (HARP), which focused on panic, agoraphobia, generalized anxiety disorder, and social phobias as "index disorders" required for intake.

RESULTS

We used various definitions for "pure culture." By all definitions, subjects with "pure culture" represented a minority, especially in cases of generalized anxiety disorder and social phobia, where comorbidity was virtually ubiquitous. "Pure culture" status was associated with later onset of illness and less chronicity.

CONCLUSION

Future studies of anxiety disorder should aim to document the extensive comorbidity, rather than eliminate it by restrictive diagnostic exclusion criteria, lest they yield atypical or even misrepresented groups of patients. Clinicians should not stop at identifying only the "main" diagnosis but look for other, comorbid diagnoses that are often present.

Low plasma gamma-aminobutyric acid levels during the late luteal phase of women with premenstrual dysphoric disorder

OBJECTIVE

Plasma gamma-aminobutyric acid (GABA) levels have been reported to be low in some patients with major depressive disorder. Premenstrual dysphoric disorder is often associated with major depressive disorder. Therefore, the authors sought to determine whether women with premenstrual dysphoric disorder with or without prior major depressive disorder also had low plasma GABA levels.

METHOD

Plasma GABA levels were measured in 27 women with premenstrual dysphoric disorder and 21 comparison women during the the mid-follicular and late luteal phases of the menstrual cycle.

RESULTS

In comparison women, plasma GABA levels increased from the mid-follicular to the late luteal phase. Women with premenstrual dysphoric disorder and a past history of major depressive disorder had low plasma GABA levels during both phases. In women with premenstrual dysphoric disorder but no past major depressive disorder, plasma GABA levels decreased from the nonsymptomatic, mid-follicular phase to the symptomatic, late luteal phase.

CONCLUSIONS

Decreased GABA function may represent a common biological link between subtypes of depressive and premenstrual dysphoric disorders. A trait in major depressive disorder and a state-dependent decrease in premenstrual dysphoric disorder might imply a possible continuum between the two disorders.

Hormone-induced conformational changes in the hepatic insulin receptor

The insulin receptor can exist in either a lower or a higher affinity state. Hormone binding alters the equilibrium between the two states of the insulin receptor, favoring the formation of that of higher affinity (Corin, R.E., and Donner, D.B. (1982), J. Biol. Chem. 257, 104-110). After brief or extended incubations with hormone, during which the fraction of higher affinity receptors increased, 125I-insulin was covalently coupled to the alpha subunits of its receptor using disuccinimidyl suberate. Some 125I-insulin remained bound to higher affinity receptors after dissociation of hormone from lower affinity sites. This hormone could also be covalently coupled to the alpha subunit of the receptor. During extended incubations between 125I-insulin and liver plasma membranes, components of the receptor were cleaved to yield degradation products of 120,000 and 23,000 Da. The significance of this process remains undetermined. Unoccupied insulin receptors were cleaved by trypsin to produce fragments of 94,000 and 37,000 Da which remained membrane-bound and could be covalently coupled to 125I-insulin. Trypsin treatment after binding yielded an additional receptor fragment of 64,000 Da. As the incubation time between 125I-insulin and membranes was lengthened, components of the receptor became progressively less sensitive to trypsin. Higher affinity binding sites isolated after release of rapid dissociating insulin were less sensitive to trypsin than were mixtures of higher and lower affinity receptors. These observations suggest that hormone binding produces two conformational changes (alterations of tryptic lability) in the hepatic insulin receptor. The first change is rapid and exposes parts of the receptor to tryptic degradation. The second, slower conformational change renders the receptor less sensitive to trypsin and occurs with the same time course as the increase of receptor affinity mediated by site occupancy.