The duration, nature and recurrence rate of brief depressions

1. It has been shown in placebo controlled studies of prophylactic treatment of suicidal behaviour in patients not suffering from major depression that brief episodes of depression predict further suicidal behaviour. 2. In a prospective follow up study of patients with a history of repeated suicidal behaviour it appears that almost all suffered recurrent episodes of brief depression, mainly of moderate to severe intensity. Two thirds of the episodes lasted between two and four days. The recurrences were frequent, irregular, and apparently unpredictable. 3. The episodes were distinguishable from major depression only by the short duration.

Plasma-level response relationships with fluoxetine and zimelidine

The results of pharmacokinetic studies of two recent 5-HT uptake inhibitors, zimelidine and fluoxetine, have pointed to the inadequacy of open-dose rising studies for establishing the most appropriate dose of new antidepressants. High plasma concentrations of the active metabolites, norzimelidine and norfluoxetine, were associated with a poorer therapeutic response in patients suffering from major depression. High drug plasma concentrations are also associated with increased side effects. Large fixed-dose placebo controlled studies with fluoxetine have confirmed the findings of the small pharmacokinetic study that lower doses are more effective. Fixed-dose pharmacokinetic studies are recommended as part of the program to establish the best dose of new antidepressants.

Early response with clomipramine in obsessive compulsive disorder--a placebo controlled study

1. Clomipramine has been found to be effective in the treatment of obsessive compulsive disorder (OCD) in nine placebo controlled studies whereas other conventional antidepressants lacking 5-HT reuptake inhibiting properties do not appear to be effective. 2. The placebo response rate in OCD is very low as is seen in the placebo controlled study of the efficacy of clomipramine 75mg in 14 patients suffering from OCD reported here. 3. Response appears early in treatment when compared with response of depression to antidepressants.

Is there a relationship between serotonin receptor subtypes and selectivity of response in specific psychiatric illnesses?

Identification of 5-HT receptor subtypes--5-HT1A, 5-HT1B, 5-HT1C, 5-HT1D, 5-HT2 (possibly A and B), 5-HT3 subtypes, and possibly 5-HT4--has encouraged the manufacture of 5-HT receptor inhibitors with greater subtype specificity. However, it appears that the receptors interact, and drugs initially thought to be specific may have multiple actions. For some conditions such as anxiety/depression, almost all receptors are implicated. Clinical studies provide clear evidence that manipulation of the 5-HT system has a role in treating depression, anxiety, obsessional illness, migraine, and eating disorders. Interactions between the various receptor subtypes make it difficult to identify specific clinical functions. The 5-HT1A receptors may be involved in aggression, anorexia, and hypotension. The 5-HT1B receptors may be involved in aggression, while the 5-HT1C receptors may play a role in central aversion systems and anxiety/depression. The role of the 5-HT1D receptors remains speculative; 5-HT2 receptors appear to be involved in depression, anxiety, appetite, sleep, vasoconstriction, and hypertension. Many drugs that are effective in treating migraine are potent 5-HT2 antagonists. 5-HT3 antagonists at high doses are effective in treating nausea and at low doses in treating anxiety. Treatment of aggression, suicidal behaviour, addiction behaviour, memory impairment, dementia, and schizophrenia with 5-HT inhibitors requires further testing.

Why do amitriptyline and dothiepin appear to be so dangerous in overdose?

Data from different analyses of reported deaths from overdose with antidepressants in the U.K. reveal that amitriptyline and dothiepin are the antidepressants most likely to be associated with death from overdose. All widely used tricyclic antidepressants (TCAs) except clomipramine and lofepramine appear to be dangerous in overdose, whereas the newer antidepressants such as mianserin, trazodone, viloxazine and the TCA lofepramine appear to be relatively safe. The toxicity of amitriptyline and dothiepin appears to be greater than all antidepressants including other TCAs and it is important to try to understand why. A number of explanations will be considered: 1. Dothiepin and amitriptyline may be inherently more toxic than other TCAs. 2. Dothiepin and amitriptyline may induce suicide more than other antidepressants. It is assumed that antidepressants are neutral with regard to inducing suicide but this may not be true. There is, for example, evidence that alprazolam and other benzodiazepines induce suicidal behaviour. 3. Amitriptyline and dothiepin are often presented in subtherapeutic and ineffective doses and it is possible that increased suicides may result from inadequately treated depression. 4. There may be a selective overreporting of deaths with amitriptyline and dothiepin. 5. Amitriptyline and prothiaden may be selectively given to the suicide prone on the mistaken assumption that they are safe.

New antidepressants and 5-HT uptake inhibitors

The efficacy of 5-HT uptake inhibitors, including paroxetine, as antidepressants is compared with that of the reference tricyclic antidepressants. It is suggested that some of the older tricyclic antidepressants might not have been released for general clinical use if tested by today's rigorous standards. Placebo-controlled, multicentre studies indicate that 5-HT uptake inhibitors are both effective as antidepressants and well tolerated by depressed patients. They also appear to have a role in the treatment of depression when associated with personality disorders, in the treatment of obsessive-compulsive disorder and bulimia, and in resistant depression. Moreover, the evidence for efficacy in the prophylaxis of depression is better established for 5-HT uptake inhibitors than for reference antidepressants.

Intermittent 3-day depressions and suicidal behaviour

Intermittent short-lived episodes of depression were examined in a group of 20 recurrent suicidal attempters without major depression, classified misleadingly as borderline personality disorders on DSM-IIIR, during careful prospective follow-up for between 4 and 6 months. The duration of depressions clustered tightly around a median of 3 days with two thirds lasting between 2 and 4 days. They occurred erratically and unpredictably with a median interval of 18 days and were seen to be moderate to severe measured on the MADRS in 70% of episodes.

Prophylaxis in recurrent unipolar depression: a new indication for treatment studies

Antidepressants are used for long periods of time and until recently there were no formal requirements for establishing efficacy in the maintenance phase or the prophylactic phase of the treatment of depression. The CPMP guidelines advise regulatory authorities in the EEC to consider the efficacy of antidepressants in the medium and the long term separately from efficacy in the treatment of the acute episode. This paper reviews the efficacy of antidepressants in continuation treatment and prophylactic treatment of unipolar depression. Prophylactic studies are difficult and time consuming and it is important to adopt adequate trial methodology. The minimum criteria for the demonstration of prophylactic efficacy are presented.

Prophylactic treatment of depression: a public health issue

The majority of depressive illness is a chronic and relapsing, frequently occurring illness, which carries significant social and economic consequences for the sufferer. Depression is also associated with increased morbidity and mortality from physical illness and suicide. Long-term antidepressant treatment is needed for at least 6 months after the resolution of the symptoms of an acute episode to consolidate recovery. In recurrent depression, treatment over a much longer period is required to reduce the risk of a new episode occurring. It is clear from the prophylactic studies, which require careful and appropriate methods, that some half of the recurrent episodes of depression are preventable by adequate prophylactic treatment with antidepressants. This effect has been clearly demonstrated with some of the newly introduced 5-HT uptake inhibitors. The disadvantages of long-term treatment have to be weighed against the risks and costs, personal, social and economic, of the illness.

The specificity of the zimelidine reaction

The first of a series of 5HT reuptake inhibitors, zimelidine was withdrawn because of associated hypersensitivity reactions. There was concern that such reactions might be seen with other compounds of this class. Two depressed patients who had a sensitivity reaction to treatment with zimelidine were crossed over to treatment with fluoxetine and no abnormalities were observed. Both patients remained well during uneventful long term treatment with fluoxetine.

The use of cholecystokinin in schizophrenia: a review

Cholecystokinin (CCK) is a peptide originally isolated from the gut. It has been investigated as a candidate treatment for schizophrenia on the assumption that the illness is associated with an imbalance between CCK and dopamine in the mesolimbic dopamine system. Many of the studies to assess the efficacy of CCK used open designs and are prone to observer bias and over-optimistic reporting. Most of the studies used CCK as an adjunct to standard neuroleptic treatment and are too small to be able to demonstrate extra efficacy above that of the active compound. Only three out of ten studies using CCK or placebo as an adjunct to neuroleptics reported limited efficacy. Of the 14 placebo-controlled reports only three were in drug-free patients. These were unfortunately too small, or too brief, to draw valid conclusions of efficacy. A summary of these data suggests that although 500 patients have received CCK, its efficacy in the treatment of schizophrenia has not been properly tested.

The psychopharmacology of borderline personality disorders

DSM-III borderline personality disorder defines a group of patients who are characterised by impulsivity and unpredictable behaviour, inappropriate aggression, intense and unstable relationships and are often associated with repeated suicidal behaviour. A substantial body of research has established an association between disturbance of serotonin and also dopamine and suicidal behaviour in depression. A similar relationship is also seen in studies of personality disorders which suggests the association is not specific to depression. A placebo controlled study of low dose flupenthixol has been shown to significantly reduce subsequent suicidal behaviour in patients with personality disorders without depression or schizophrenia. Evidence points to a biological basis for suicidal behaviour and borderline personality disorder and possibly of pharmacotherapy.

Profiles of antidepressant activity with the Montgomery-Asberg Depression Rating Scale

The Montgomery and Asberg Depression Rating Scale (MADRS) is a 10 item severity scale constructed to be sensitive to change with treatment. It was designed to be sensitive for individual items and is therefore useful for measuring differential profiles of action. The MADRS profiles of activity were examined in a six-week double-blind comparative group study of depressed patients treated with mianserin or zimeldine. Three of the ten items on the MADRS showed individual significant advantages for mianserin, reduced sleep (weeks 1 and 3), concentration difficulties (week 1), and reduced appetite (week 3). These findings are in agreement with earlier reports of poor sleep and gastrointestinal upset associated with the 5-HT uptake inhibitor zimeldine. The selective improvement in concentration difficulties and in the other items support the view that mianserin is particularly useful in alleviating the anxiety associated with depression. The sedative effect of mianserin did not appear to interfere with concentration. There were significant improvements in the mianserin-treated group at 1, 2, 3, and 4 weeks for the MADRS, Hamilton Depression Rating Scale and Clinicians Global Impression scale. There was no significant advantage for mianserin at 5 and 6 weeks. The differential clinical effects were apparent early in the study but any selectivity of action appeared to be overwhelmed by the general antidepressant effect later in treatment.

Development of new treatments for depression

The mixed actions of the older tricyclic antidepressants make them generally unsuitable as pharmacologic tools in investigating mechanisms of antidepressant effect. Tricyclics are also relatively dangerous in overdose, and their patient acceptability is limited by marked side effects and cardiotoxicity. The current trend in the development of new antidepressants is to identify pharmacologically active molecules that have selective action. Compounds with a selective effect in blocking serotonin reuptake have recently been developed. Among these, fluoxetine is of substantial theoretical interest because, unlike other serotonin uptake inhibitors, it is rather specific and does not appear to down-regulate beta-receptors. Assessment of the relative efficacy of such compounds should provide insight into the mechanisms of antidepressant effect. Prerequisites of clinical trials for new antidepressants are briefly reviewed.