Some of the problems and difficulties associated with clinical studies of antidepressant agents

A regression analytical approach to estimate the onset of activity of antidepressants

The onset of activity of antidepressants is a clinically and theoretically important criterion of efficacy. We estimated the onset of activity by an intraindividual regression analytical approach. It is assumed that efficient treatment causes a fast shift of depression scores from a baseline level to an end level. From this assumption follows a limited number of opportunities for the onset of activity to occur. These opportunities correspond to different regression models which are estimated for each patient's depression course. The day of onset is concluded from the regression model which produces the best fit to the empirical depression curve. Results of a double-blind clinical trial comparing mianserin and amitriptyline are reported (n = 28). The methodological approach confirms that observer ratings by physicists show a significantly earlier onset of activity than self ratings by the patients. The D-S also shows a significantly earlier onset of activity of mianserin compared to amitriptyline. The discussion emphasises methodological aspects.

Drug evaluation and the permissive principle: continuities and contradictions between standards and practices in antidepressant regulation

Pharmaceuticals are not permitted on to the market unless they are granted regulatory approval. The regulatory process is, therefore, crucial in whether or not a drug is widely prescribed. Regulatory agencies have developed standards of performance that pharmaceuticals are supposed to meet before entering the market. Regulation of technologies is often discussed by reference to the precautionary principle. In contrast, this paper develops the concept of the 'permissive principle' as a way of understanding the departure of regulators' practices from standards of drug efficacy to which regulatory agencies themselves subscribe. By taking a case study of antidepressant regulation in the UK and the USA, the mechanisms of permissive regulatory practices are examined. An STS methodology of both spatial (international) and temporal comparisons of regulatory practices with regulatory standards is employed to identify the nature and extent of the permissive regulation. It is found that the permissive principle was adopted by drug regulators in the UK and the USA, but more so by the former than the latter. Evidently, permissive regulation, which favours the commercial interests of the drug manufacturer, but is contrary to the interests of patients, may penetrate to the heart of regulatory science. On the other hand, permissive regulation of specific drugs should not be regarded as an inevitable result of marketing strategies and concomitant networks deployed by powerful pharmaceutical companies, because the extent of permissive regulation may vary according to the intra-institutional normative commitments of regulators to uphold their technical standards against the commercial interests of the manufacturer. Likely sociological factors that can account for such permissive regulatory practices are 'corporate bias', secrecy and excessive regulatory trust in the pharmaceutical industry in the UK, political expediency and ideological capture in the USA, combined in both countries with some regulatory deference to the clinical autonomy of the psychiatry profession.

The politics and bio-ethics of regulatory trust: case-studies of pharmaceuticals

Drawing on case studies from the modern era of pharmaceutical regulation in the UK, US and Europe, I examine how the extent and distribution of trust between regulators, the pharmaceutical industry, and the medical profession about drug testing and monitoring influences knowledge and regulatory judgements about the efficacy and safety of prescription drugs. Introducing the concepts of 'acquiescent' and 'investigative' norms of regulatory trust, I demonstrate how investigative norms of regulatory trust-which deter pharmaceutical companies from assuming that their data analyses will be accepted without independent de-construction-drive up bioethical and regulatory standards of drug assessment in the interests of health. By contrast, acquiescent norms of regulatory trust, which are associated with industrial capture and professional closure of interests, promote permissive standards allowing patients to take pharmaceuticals with greater risks to health and less evidence of therapeutic efficacy.

Acute antidepressant effect of lithium is associated with fluctuation of calcium and magnesium in plasma. A double-blind study on the antidepressant effect of lithium and clomipramine

In a double-blind study on 22 patients with major depressive disorder the effects of lithium and clomipramine on signs and symptoms and on calcium and magnesium in plasma were compared. Ratings of antidepressant and side effects were performed by 2 psychiatrists at the end of a placebo period of 5-7 days and after treatment for 2 and 4 weeks. Psychopathology was rated by 15 reported and 4 observed items from the Comprehensive Psychopathological Rating Scale (CPRS). Eleven items present in 72-100% of the patients were used to evaluate the effect of the two drugs. After 2 weeks of treatment the rated scores dropped for more than half of the CPRS items. After 4 weeks the scores for all but one item were reduced in both groups. The sums of scores were significantly reduced after 2 weeks in both groups and after 4 weeks global scores were reduced as well. The drugs had notable and similar antidepressant effects. Lithium treatment was associated with fluctuations in calcium and magnesium levels in plasma not seen during clomipramine treatment. Serum prolactin increased during clomipramine treatment but was unaffected by lithium treatment. No correlations were found between the sum of rating scores and blood levels of drugs, prolactin, calcium or magnesium.

The premenstrual syndrome: selection of women for treatment trials

Statements made at interview by 31 women presenting with the premenstrual syndrome (PMS) were compared with the moods and physical symptoms reported daily during the next 6 menstrual cycles. Diagnosis was confirmed in 21 women (premenstrual tension (PMT) present in greater than or equal to 5/6 cycles), not substantiated in two (PMT in less than or equal to 1/6 cycles) and in doubt in eight. Placebo treatment was associated with a significant over-all reduction in both the incidence and the severity of mood-related PMT, but had no clear effect on premenstrual physical symptoms; women with PMT in 5 cycles were usually placebo-resistant. Criteria are proposed for the selection of women for treatment trials based on their response to placebo.

On finding depressed patients for clinical trials

A special clinic was set up in an attempt to overcome the problem of accumulating a sufficient number of depressed patients for inclusion in clinical trials. Only 21 patients of the 81 patients referred during 1 year fulfilled the criteria for inclusion in the trials. The function of the special clinic did not prove successful as a similar proportion of depressed patients was found in a comparison group referred to the district psychiatric outpatient clinic.

The response of endogenously and reactivity depressed patients to electroconvulsive therapy

Patients diagnosed as reactively or endogenously depressed were given electroconvulsive therapy (ECT). The endogenously depressed patients tended to respond to the treatment more quickly and favourably. Measures of age and severity of depression were as predictive as the classification into endogenous or reactive depression using the Newcastle rating scale. The degree of psychological stress ascertained and presumed to be operating did not contribute to the prediction of outcome.

Bromocriptine in depression

A double-blind trial was carried out in 9 patients with endogenous depression to compare the effectiveness of bromocriptine (15 mg per day, 4 patients) with that of imipramine (75 mg per day, 5 patients) over a period of 10 weeks. The results of assessments using the Hamilton Rating Scale for Depression showed that both drugs produced comparable reduction in mean scores and there was no significant difference between the two treatment groups. Fewer patients han anticholinergic type side-effects on bromocriptine although some had transient nausea.

The assessment of the symptoms of premenstrual syndrome and their response to therapy

The symptoms of premenstrual syndrome should be rated daily, or at frequent intervals throughout the menstrual cycle. Self-rating is usually most feasible and separate rating of differing symptom groups is important, as symptoms differ in their response to therapy. Daily scores should be analysed to assess periodicity, either by subdividing the cycle into phases or by using the least mean square method of fitting sine waves. Standardized scores enable data to be compared across cycles. In a clinical trial it is important to include an untreated cycle to assess whether the subject has premenstrual syndrome and as a baseline with which to compare treated cycles. Allowance should be made for a carry-over effect and for high placebo response. One solution is to use a change-over design balanced for carry-over effects. The criteria used to define a patient should be stated.

Controlled studies of the acute antidepressant effects of lithium

In two randomized double-blind controlled trials on 63 depressed female in-patients subject to recurrent affective disorder (bipolar and unipolar manic-depressive psychosis) lithium was shown to have major acute antidepressant effects. At the end of three weeks lithium produced more uniform improvement than did imipramine; lithium in combination with tryptophan (in the form of Optimax) was superior to tryptophan alone--the latter drug having no discernible antidepressant activity in this group of patients. Lithium did not produce an antidepressant effect until the second and third week of both trials.

A review of controlled studies with nomifensine, performed outside the UK

1. Double-blind controlled comparisons of nomifensine with placebo, imipramine, desipramine, viloxazine, nortriptyline, a combination of amitriptyline and chlordiazepoxide, and diazepam have been carried out in various parts of the world. 2. Dosage ranged from 50-225 mg daily, and treatment lasted from 2-26 weeks. 3. Nomifensine was shown to possess useful antidepressive activity, to counteract inhibition, to restore drive and to relieve anxiety. 4. Adverse reactions were uncommon, particularly anticholinergic effects, and nomifensine was not shown to cause sedation or to interact with alcohol. No withdrawal phenomena were observed after 6 months' treatment. 5. Nomifensine is not suitable for severely agitated patients.