Serotonin reuptake inhibitors are the treatment of choice in obsessive compulsive disorder

Evidence-based pharmacotherapy for obsessive–compulsive disorder

The development of effective pharmacotherapy has revolutionised the treatment of obsessive–compulsive disorder (OCD), and has generated an explosion of interest in this previously poorly understood area of psychiatry. Once considered a rare, refractory form of learnt behaviour, we now recognise OCD to be a common, treatable illness, with a distinctive pathophysiology and pharmacology. Wide-ranging epidemiological surveys have demonstrated a surprisingly high lifetime prevalence amounting to 2–3% of the general population worldwide (Robins et al, 1984). Yet only a fraction of sufferers come forward for treatment and often the diagnosis is missed.

Outlining new frontiers for the comprehension of obsessive-compulsive disorder: a review of its relationship with fear and anxiety

Anxiety is an important component of the psychopathology of the obsessive-compulsive disorder (OCD). So far, most interventions that have proven to be effective for treating OCD are similar to those developed for other anxiety disorders. However, neurobiological studies of OCD came to conclusions that are not always compatible with those previously associated with other anxiety disorders.

OBJECTIVES

The aim of this study is to review the degree of overlap between OCD and other anxiety disorders phenomenology and pathophysiology to support the rationale that guides research in this field.

RESULTS

Clues about the neurocircuits involved in the manifestation of anxiety disorders have been obtained through the study of animal anxiety models, and structural and functional neuroimaging in humans. These investigations suggest that in OCD, in addition to dysfunction in cortico-striatal pathways, the functioning of an alternative neurocircuitry, which involves amygdalo-cortical interactions and participates in fear conditioning and extinction processes, may be impaired.

CONCLUSION

It is likely that anxiety is a relevant dimension of OCD that impacts on other features of this disorder. Therefore, future studies may benefit from the investigation of the expression of fear and anxiety by OCD patients according to their type of obsessions and compulsions, age of OCD onset, comorbidities, and patterns of treatment response.

Olanzapine, but not fluoxetine, treatment increases survival in activity-based anorexia in mice

Anorexia nervosa (AN) is an eating disorder characterized by extreme hypophagia, hyperactivity, and fear of weight gain. No approved pharmacological treatments exist for AN despite high mortality rates. The activity-based anorexia (ABA) phenomenon models aspects of AN in rodents, including progressive weight loss, reduced food intake, and hyperactivity. First, we optimized the ABA paradigm for mice. We compared mouse strains (Balb/cJ, A/J) for susceptibility with ABA, and evaluated the effects of different food access durations (2, 4, 6, 8, and 10 h) on ABA parameters. Balb/cJ mice exhibited significantly shorter survival time (days until 25% bodyweight loss) in the ABA paradigm compared with A/J mice. Furthermore, 6 h of food access reduced survival in mice housed with wheels without reducing survival in mice housed without wheels. We then evaluated the effects of chronic treatment with fluoxetine (4 weeks) or subchronic treatment with olanzapine (OLZ) (1 week) on ABA in BALB/cJ mice. OLZ (12 mg/kg/day) significantly increased survival and reduced food anticipatory activity (FAA). However, OLZ did not alter food intake or running wheel activity during ad-lib feeding (baseline) or restriction conditions, or in mice housed without wheels. Fluoxetine (18 mg/kg/day) increased food intake and reduced FAA, but did not alter survival. Here, we report for the first time that OLZ, but not fluoxetine, reduces ABA in mice. Our findings indicate further need for clinical investigations into the effects of OLZ, but not selective serotonin reuptake inhibitors, on core features of AN.

A novel potential therapeutic avenue for autism: design, synthesis and pharmacophore generation of SSRIs with dual action

Autism symptoms are currently modulated by Selective Serotonin Reuptake Inhibitors (SSRIs). SSRIs slow onset of action limits their efficiency. The established synergistic activity of SSRIs and 5HT(1B/1D) autoreceptors antagonists motivated us to incorporate SSRIs and 5HT(1B/1D) antagonists in one 'hybrid' molecule. A library of virtual 'hybrid' molecules was designed using the tethering technique. A pharmacophore model was generated derived from 16 structurally diverse SSRIs (K(i)=0.013-5000 nM) and used as 3D query. Compounds with fit values (≥2) were chosen for synthesis and subsequent in vitro biological evaluation. Our pharmacophore model is a promising milestone to a class of SSRIs with dual action.

Mechanisms of action of current and potential pharmacotherapies of obsessive-compulsive disorder

A significant body of evidence documented that the orbitofrontal cortex (OFC) and the head of caudate nucleus are involved in the mediation of obsessive-compulsive disorder (OCD) symptoms. Potent serotonin (5-HT) reuptake inhibitors (SRIs) are the only antidepressant agents thus far shown to be effective in the treatment of OCD. The present review summarizes information on 5-HT release and the adaptive changes in pre- and postsynaptic 5-HT receptors sensitivity induced by SRI treatment in rat and guinea pig structures involved in OCD. It emphasizes that the time course for the occurrence of increased 5-HT release and terminal 5-HT1D desensitization is congruent with the delayed therapeutic response to SRI in OCD. In addition, a greater dose of SRI inducing a greater degree of reuptake inhibition may play an essential role in this phenomenon. This is consistent with the common clinical observation that high doses of SRIs are sometimes necessary to obtain an anti-OCD effect, and with the results of some fixed-dose double blind trials showing a dose-dependent therapeutic effect of SRIs. It is hypothesized that enhanced 5-HT release in the OFC is mediated by the activation of normosensitive postsynaptic 5-HT2-like receptors and underlies the therapeutic action of SRI in OCD. This is supported by the beneficial effect of some hallucinogens with 5-HT2 agonistic properties in obtaining a more rapid therapeutic response. Finally, based on this knowledge, new strategies aimed at producing more rapid, effective and safe anti-OCD drugs, such as a selective action on terminal 5-HT1D receptors, on 5-HT2 receptors as well as on the glutamate system, are discussed.

Low-dose risperidone augmentation of fluvoxamine treatment in obsessive-compulsive disorder: a double-blind, placebo-controlled study

According to previous data, the addition of risperidone in obsessive-compulsive patients refractory to serotonin reuptake inhibitors (SRIs) is shown to be a safe and effective treatment strategy. The aims of our study were to evaluate the efficacy of risperidone addition, in comparison to placebo, in fluvoxamine-refractory obsessive-compulsive patients and to investigate whether risperidone could boost the efficacy of fluvoxamine in fluvoxamine-responder patients. Subjects were 45 obsessive-compulsive inpatients, consecutively recruited at the Department of Neurosciences at the San Raffaele Hospital, Milan. Thirty-nine patients completed the study. All patients received 12 weeks of a standardized open-label fluvoxamine monotherapy and then continued for 6 weeks with placebo or risperidone in a double-blind design. Results showed a significant effect of risperidone addition, at the end of the double-blind phase (18th week), only for fluvoxamine-refractory patients. Five patients on risperidone (50%) and two (20%) on placebo became responders, with a Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) decrease > or =35%. Risperidone was generally well tolerated, except for a mild transient sedation and a mild increase in appetite. This preliminary study suggests that even very low (0.5 mg) risperidone doses are effective in OC patients who were nonresponders to a standardized treatment with fluvoxamine.

Antidepressant-like effects of tramadol and other central analgesics with activity on monoamines reuptake, in helpless rats

Affective states are regulated mainly by serotonin and noradrenaline. However the opioid system has been also related to antidepressant-induced mood improvement, and the mu-opioid receptor has been involved in affective responses to a sustained painful stimulus. Similarly, antidepressant drugs induce an antinociceptive effect via both the monoaminergic and opioid systems, probably involving sensorial and affective dimensions of pain. The aim of this study was to test three opiate analgesics, which also inhibit monoamine reuptake, in the learned helplessness model of depression in rats. Helpless rats receiving (+/-)tramadol (10, 20 mg/Kg) or (-)methadone (2, 4 mg/Kg) showed a decreased number of failures to avoid or escape aversive stimulus (shock) in both the second and the third daily sessions, compared with controls. Rats receiving levorphanol (0.5, 1 mg/Kg) showed a decreased number of such failures in the third session. The number of crossings in the intertrial interval (ITI) was not significantly modified by (+/-)tramadol or (-)methadone. Levorphanol enhanced ITI crosses at 1 mg/Kg. These results, together with other clinical and experimental data, suggest that analgesics with monoaminergic properties improve mood and that this effect may account for their analgesic effect in regulating the affective dimension of pain. From this, it seems probable that the analgesic effect of opiates could be induced by adding together the attenuation produced of both the sensorial and the affective dimensions of pain.

Fluvoxamine in obsessive-compulsive disorder: similar efficacy but superior tolerability in comparison with clomipramine

Some meta-analyses have suggested that the selective serotonin reuptake inhibitors (SSRIs) are less effective than clomipramine in the treatment of obsessive-compulsive disorder (OCD). The aim of this double-blind, randomised, multicentre study was to directly compare the efficacy and safety of fluvoxamine and clomipramine in patients with OCD. A total of 227 patients were randomised to flexible doses of fluvoxamine or clomipramine (both 150-300 mg/day) for 10 weeks. Fluvoxamine and clomipramine were both clinically effective and there were no statistically significant differences between the two treatment groups, at any visit, on the National Institute of Mental Health Obsessive-Compulsive global rating scale, the Yale-Brown Obsessive-Compulsive scale (total score and obsession and compulsion subscores), the Clinical Global Impression severity of illness and global improvement subscales, the Clinical Anxiety Scale and the 17-item Hamilton Depression Rating Scale. However, there were differences in safety between the two treatments. Compared with fluvoxamine-treated patients, those treated with clomipramine had more anticholinergic side effects (dry mouth, constipation and tremor) and premature withdrawals due to adverse events (18 versus 9). The results from this controlled study indicate that fluvoxamine is as effective as clomipramine in the treatment of OCD but has a better tolerability profile. Copyright 2001 John Wiley & Sons, Ltd.

Obsessive-complusive disorder: pharmacological treatment

Obsessive-compulsive disorder (OCD) in children and adolescents is often a disabling condition, which demands treatment with medication. Research shows that serotonin is involved in the disorder and empirical treatment studies show that antidepressants with serotonin activity are effective. The first choice of treatment in the psychopharmacological approach to OCD in children and adolescents are the SSRI agents, which have been documented as being effective as well as well-tolerated in children and adolescents. The best-documented SSRI to this point is sertraline. However, fluoxetine and fluoxamine have also undergone systematic studies in children and adolescents. Clomipramine has been proven effective, however, side effects caused by this agent would suggest that an SSRI is a better choice. Treatment with an SSRI seems to have effect in approximately 75 % of patients with OCD. There are still no systematic studies analyzing augmenting medication for children and adolescents with OCD. Research indicates that the combination of medication and psychotherapy (cognitive behavioural therapy) is important in most cases. Based on a few long-term follow-up studies on OCD children and adolescents there is not evidence that all children and adolescents suffer a lifetime course of the disease. It is therefore recommended that discontinuation is attempted after 1-1.5 years of successful treatment.

Effect of long-term administration of antidepressant treatments on serotonin release in brain regions involved in obsessive-compulsive disorder

BACKGROUND

Among all antidepressant treatments, including electroconvulsive shock (ECS) therapy and monoamine oxidase inhibitors (MAOIs), only the selective serotonin (5-HT) reuptake inhibitors (SSRIs) exert a clear therapeutic effect in obsessive-compulsive disorder (OCD). An 8-week, but not a 3-week treatment with the SSRI paroxetine results in an increased electrically evoked [3H]5-HT release and a desensitization of 5-HT autoreceptors in the guinea pig orbitofrontal cortex, a brain region implicated in OCD.

METHODS

In the present study, the effect of long-term treatment with the SSRI fluoxetine, ECS, and the reversible type A MAOI moclobemide was investigated on evoked [3H]5-HT release from preloaded guinea pig brain slices prepared from the hypothalamus, cingulate cortex, and orbitofrontal cortex.

RESULTS

Fluoxetine treatment yielded an enhanced [3H]5-HT release in the three brain areas, but a desensitization of the 5-HT autoreceptor only in the hypothalamus and orbitofrontal cortex. ECS treatment did not result in any alteration of the electrically evoked [3H]5-HT release or of 5-HT autoreceptor sensitivity in any of the brain regions. Moclobemide increased [3H]5-HT release only in the orbitofrontal cortex without any alteration in the 5-HT autoreceptor sensitivity.

CONCLUSIONS

These findings indicate that only treatments effective in OCD have the capacity to desensitize the terminal 5-HT autoreceptor in the orbitofrontal cortex.

Circulating lymphocyte subsets in obsessive compulsive disorder, major depression and normal controls

BACKGROUND

Obsessive compulsive disorder (OCD) shares several features with depressive illness (e.g., comorbidity, early escape from dexamethasone suppression, effectiveness of serotonergic pharmacotherapy). It was of interest to establish whether OCD, like major depression, was also associated with immune alterations, notably elevations of circulating natural killer (NK) cells.

METHOD

Circulating lymphocytes were determined from morning blood samples taken from OCD and major depressive patients, as well as from age- and sex-matched controls. Stress perception and coping styles were evaluated in order to assess whether such variables accompanied the NK alterations. Finally, in a subset of patients, symptoms of the illness, stress/coping, and circulating lymphocytes, were also evaluated following 12 weeks of antidepressant medication (serotonergic reuptake inhibitor).

RESULTS

The major depressive and OCD patients reported increased perception of day-to-day stresses, coupled with reliance on emotion focused coping styles. Moreover, circulating NK cells were elevated among male OCD and major depressive patients, whereas only a modest increase of NK cells was seen in female major depressives. Twelve weeks of medication alleviated depressive and OCD symptoms, and resulted in normalization of NK cells in the major depressives. However, in OCD patients the reduction of symptoms was not accompanied by significant variations of circulating NK cells.

CONCLUSIONS

Although major depression and OCD are both accompanied by elevated circulating NK cells, at least in males, normalization of NK cells following treatment was only evident in depression. The persistent elevations of NK cells among male OCD patients may reflect either a trait characteristic of the illness, or symptom reduction and not true remission.

LIMITATIONS

Although elevations of lymphocyte subsets in major depressive and OCD patients were observed, conclusions concerning immune status in OCD ought to be held in abeyance pending assessment of other indices of immune and cytokine functioning.

Paroxetine versus clomipramine in the treatment of obsessive-compulsive disorder. OCD Paroxetine Study Investigators

BACKGROUND

The aim was to assess the effect of a flexible dose of paroxetine, compared with clomipramine and placebo, in obsessive-compulsive disorder (OCD).

METHOD

In a multinational randomised study, 406 subjects with OCD of at least six months duration received double-blind medication for up to 12 weeks. Doses were adjusted according to therapeutic effect and side-effects. Primary efficacy measures were the Yale-Brown Obsessive-Compulsive Scale and the National Institute of Mental Health Obsessive-Compulsive Scale. Secondary efficacy measures were the Montgomery-Asberg Depression Rating Scale, Symptom Check-List (90), Clinical Global Impression, and Patients Global Evaluation.

RESULTS

Paroxetine was significantly more effective than placebo, and of comparable efficacy to clomipramine. Paroxetine had significantly superior tolerability to clomipramine on three measures: CGI efficacy index, anticholinergic adverse events, and adverse events leading to withdrawal.

CONCLUSION

Paroxetine is as effective as clomipramine in the treatment of OCD. The comparable efficacy and better tolerability of paroxetine suggest that it would be an appropriate treatment for OCD.

Treatment of obsessive-compulsive disorder in children and adolescents. A review of the literature

The literature on treatment of childhood and adolescent obsessive-compulsive disorder is reviewed. Most studies concerning treatment of obsessive-compulsive disorder has been based on experience from adult patients. Only a few controlled trials using medication with obsessive-compulsive children have been produced. No controlled study has as yet documented the effect of behavioural therapy alone. The most effective treatment seems to be a combination of behavioural therapy and medication with a serotonin reuptake inhibitor. In the treatment of children with OCD, it is important to consider the child's personality and comorbid disorders.

Regional 133xenon cerebral blood flow and cerebral 99mTc-HMPAO uptake in patients with obsessive-compulsive disorder before and during treatment

We previously reported increased regional cerebral cortical uptake and decreased caudate nucleus uptake of 99mTc-HMPAO in patients with obsessive-compulsive disorder(OCD) before treatment compared to matched normal controls. In the present study, we determined whether or not these changes persisted during treatment. Single-photon emission computed tomography was used to measure regional cerebral blood flow (rCBF) by 133Xe inhalation and cerebral uptake of 99mTc-HMPAO in eight adult male OCD patients before and during treatment with chlomipramine, and in eight age-matched normal male controls. With 133Xe, there were no significant differences in rCBF between patients with OCD and their matched controls, and no significant differences in rCBF in the patients before and during treatment. Significantly increased HMPAO uptake in the orbital frontal cortex, posterofrontal cortex, and high dorsal parietal cortex bilaterally occurred in the OCD patients before treatment compared to their matched controls, and there were significant reductions of HMPAO uptake, into the normal range, in all these areas in the patients during treatment. Significantly reduced HMPAO uptake in the caudate nucleus bilaterally occurred in the patients before treatment compared to their matched controls, and these reductions persisted during treatment. This study provides additional support for the involvement of both the orbital frontal cortex and the caudate nuclei in the pathophysiology of OCD.

Neuroendocrine responses to intravenous L-tryptophan in obsessive compulsive disorder

We studied the neuroendocrine responses produced by intravenous L-tryptophan (TRP) in 16 untreated patients with obsessive compulsive disorder (OCD) and 16 matched healthy controls. The increase in plasma growth hormone seen following TRP was significantly greater in the OCD patients, while TRP-induced prolactin release did not differ from controls. Taken in conjunction with findings from other neuroendocrine studies the data suggest that some aspects of 5-HT1A neurotransmission may be increased in OCD. This increase may represent a compensatory change which promotes adaptation to stress in non-depressed OCD patients.

Obsessive-compulsive disorder: admission patterns and diagnostic stability. A case-register study

All first-time admissions from 1970 to 1986 with obsessive-compulsive neurosis (OCD) (ICD-8 diagnosis number 300.39) or obsessive-compulsive personality disorder (OCPD) (ICD-8 diagnosis number 301.49) were analyzed based on an extract from the nationwide Psychiatric Case Register in Denmark. All patients with secondary diagnoses other than neurotic disorders or personality disorders (including "neuroses characterogenes") were excluded from the study. A total of 284 patients were first-time admitted with a main diagnosis of OCD during the period. The sex ratio was 0.67 (males/females). A total of 126 were first-time admitted with a diagnosis of OCPD, with a sex ratio of 1.18 (males/females). Seventy-seven percent of the readmitted patients with a first-time diagnosis of OCD kept a diagnosis within the "emotional spectrum" at the last admission. About half kept OCD as a main diagnosis, whereas only 15% shifted to a severe psychiatric diagnosis such as schizophrenia or manic-depressive psychosis. Of the readmitted patients with OCPD, 13% later developed a diagnosis of manic-depressive psychosis.

Individual differences in cerebral metabolic patterns during pharmacotherapy in obsessive-compulsive disorder: a multiple regression/discriminant analysis of positron emission tomographic data

A multiple regression/discriminant analysis of positron emission tomographic cerebral metabolic (rCMRglc) data in 10 obsessive-compulsive disorder (OCD) patients before and during pharmacotherapy was carried out to see if rCMRglc interdependencies distinguished OCD patients from controls. Before therapy, a discriminant function reflecting parietal, sensorimotor, and midbrain rCMRglc interdependencies correctly classified eight (80%) of the 10 patients as OCD; after therapy, six (70%) were classified as controls, most of whom were responders. Before therapy, rCMRglc interdependencies involving basal ganglia, thalamus, limbic, and sensory and association cortical regions distinguished 67% of patients who clinically responded to drug (RESP, n = 6) and 75% of patients who did not (NRESP, n = 4) from controls. After therapy, all RESP were classified as controls; classification of NRESP remained unchanged. The results suggest the conjunctive utility of this method to assess individual differences in rCMRglc during pharmacotherapy, and to explore the neurobiology of OCD.