[11C]PBR28 MR-PET imaging reveals lower regional brain expression of translocator protein (TSPO) in young adult males with autism spectrum disorder.

Mechanisms of neuroimmune and mitochondrial dysfunction have been repeatedly implicated in autism spectrum disorder (ASD). To examine these mechanisms in ASD individuals, we measured the in vivo expression of the 18 kDa translocator protein (TSPO), an activated glial marker expressed on mitochondrial membranes. Participants underwent scanning on a simultaneous magnetic resonance-positron emission tomography (MR-PET) scanner with the second-generation TSPO radiotracer [11C]PBR28. By comparing TSPO in 15 young adult males with ASD with 18 age- and sex-matched controls, we showed that individuals with ASD exhibited lower regional TSPO expression in several brain regions, including the bilateral insular cortex, bilateral precuneus/posterior cingulate cortex, and bilateral temporal, angular, and supramarginal gyri, which have previously been implicated in autism in functional MR imaging studies. No brain region exhibited higher regional TSPO expression in the ASD group compared with the control group. A subset of participants underwent a second MR-PET scan after a median interscan interval of 3.6 months, and we determined that TSPO expression over this period of time was stable and replicable. Furthermore, voxelwise analysis confirmed lower regional TSPO expression in ASD at this later time point. Lower TSPO expression in ASD could reflect abnormalities in neuroimmune processes or mitochondrial dysfunction.

Positive effects of methylphenidate on hyperactivity are moderated by monoaminergic gene variants in children with autism spectrum disorders.

Methylphenidate (MPH) reduces hyperactive-impulsive symptoms common in children with autism spectrum disorders (ASDs), however, response and tolerability varies widely. We hypothesized monoaminergic gene variants may moderate MPH effects in ASD, as in typically developing children with attention-deficit/hyperactivity disorder. Genotype data were available for 64 children with ASD and hyperactivity who were exposed to MPH during a 1-week safety/tolerability lead-in phase and 58 who went on to be randomized to placebo and three doses of MPH during a 4-week blinded, crossover study. Outcome measures included the Clinical Global Impression-Improvement (CGI-I) scale and the Aberrant Behavior Checklist (ABC-hyperactivity index). A total of 14 subjects discontinued the study because of MPH side effects. Subjects were genotyped for variants in DRD1-DRD5, ADRA2A, SLC6A3, SLC6A4, MAOA and MAOB, and COMT. Forty-nine percent of the sample met positive responder criteria. In this modest but relatively homogeneous sample, significant differences by DRD1 (P=0.006), ADRA2A (P<0.02), COMT (P<0.04), DRD3 (P<0.05), DRD4 (P<0.05), SLC6A3 (P<0.05) and SLC6A4 (P<0.05) genotypes were found for responders versus non-responders. Variants in DRD2 (P<0.001) and DRD3 (P<0.04) were associated with tolerability in the 14 subjects who discontinued the trial. For this first MPH pharmacogenetic study in children with ASD, multiple monoaminergic gene variants may help explain individual differences in MPH's efficacy and tolerability.

The Home Situations Questionnaire-PDD version: factor structure and psychometric properties.

BACKGROUND: The Home Situations Questionnaire (HSQ) is a caregiver-rated scale designed to assess behavioural non-compliance in everyday settings that has been used in several studies in typically developing children. Currently there is no accepted measure of behavioural non-compliance in children with pervasive developmental disorders (PDDs). METHODS: Investigators of the Research Units on Pediatric Psychopharmacology Autism Network modified the HSQ for children with PDDs by adding five items (making 25 total items), and used it as the primary outcome measure in a clinical trial. In the current investigation, we examined the factor structure and psychometric properties of the modified scale, the HSQ-PDD. RESULTS: An exploratory factor analysis with oblique rotations yielded two factors: 'Socially Inflexible' (14 items) and 'Demand-Specific' (six items). Item content of both factors appeared to fit well with the rubric of PDDs. Internal consistency, using Cronbach's alpha statistic, was 0.90 for 'Socially Inflexible', and 0.80 for 'Demand-Specific.' The obtained sub-scales and HSQ-PDD Total score showed moderate correlations with selected sub-scales of the Aberrant Behavior Checklist, Child and Adolescent Symptom Inventory, and Children's Yale-Brown Obsessive Compulsive Scale, and low correlations with the Vineland Adaptive Behavior sub-scales. CONCLUSIONS: The HSQ-PDD appears to be well suited for children with PDDs, although the Demand-Specific sub-scale may benefit from addition of more items. We provided sub-scale means and standard deviations for this relatively severe group of children with PDDs, and discussed the factor structure with respect to previous research.

A Protocol for Sedation Free MRI and PET Imaging in Adults with Autism Spectrum Disorder.

Imaging technologies such as positron emission tomography (PET) and magnetic resonance imaging (MRI) present unparalleled opportunities to investigate the neural basis of autism spectrum disorder (ASD). However, challenges such as deficits in social interaction, anxiety around new experiences, impaired language abilities, and hypersensitivity to sensory stimuli make participating in neuroimaging studies challenging for individuals with ASD. In this commentary, we describe the existent training protocols for preparing individuals with ASD for PET/MRI scans and our own experience developing a training protocol to facilitate the inclusion of low-functioning adults with ASD in PET-MRI studies. We hope to raise awareness of the need for more information exchange between research groups about lessons learned in this context in order to include the entire disease spectrum in neuroimaging studies.

Communication Deficits and the Motor System: Exploring Patterns of Associations in Autism Spectrum Disorder (ASD).

Many children with autism spectrum disorder (ASD) have notable difficulties in motor, speech and language domains. The connection between motor skills (oral-motor, manual-motor) and speech and language deficits reported in other developmental disorders raises important questions about a potential relationship between motor skills and speech-language deficits in ASD. To this end, we examined data from children with ASD (n = 1781), 2-17 years of age, enrolled in the Autism Speaks-Autism Treatment Network (AS-ATN) registry who completed a multidisciplinary evaluation that included diagnostic, physical, cognitive and behavioral assessments as part of a routine standard of care protocol. After adjusting for age, non-verbal IQ, Attention Deficit Hyperactivity Disorder (ADHD) medication use, and muscle tone, separate multiple linear regression analyses revealed significant positive associations of fine motor skills (FM) with both expressive language (EL) and receptive language (RL) skills in an impaired FM subgroup; in contrast, the impaired gross motor (GM) subgroup showed no association with EL but a significant negative association with RL. Similar analyses between motor skills and interpersonal relationships across the sample found both GM skills and FM skills to be associated with social interactions. These results suggest potential differences in the contributions of fine versus gross motor skills to autistic profiles and may provide another lens with which to view communication differences across the autism spectrum for use in treatment interventions.

A double-blind, placebo-controlled study of risperidone addition in serotonin reuptake inhibitor-refractory obsessive-compulsive disorder.

BACKGROUND: To date, only 1 controlled study has found a drug (haloperidol) to be efficacious in augmenting response in patients with obsessive-compulsive disorder (OCD) refractory to serotonin reuptake inhibitor (SRI) monotherapy; patients with comorbid chronic tic disorders showed a preferential response. This report describes the first controlled study of risperidone addition in patients with OCD refractory to treatment with SRI alone. METHODS: Seventy adult patients with a primary DSM-IV diagnosis of OCD received 12 weeks of treatment with an SRI. Thirty-six patients were refractory to the SRI and were randomized in a double-blind manner to 6 weeks of risperidone (n = 20) or placebo (n = 16) addition. Behavioral ratings, including the Yale-Brown Obsessive Compulsive Scale, were obtained at baseline and throughout the trial. Placebo-treated patients subsequently received an identical open-label trial of risperidone addition. RESULTS: For study completers, 9 (50%) of 18 risperidone-treated patients were responders (mean daily dose, 2.2 +/-0.7 mg/d) compared with 0 of 15 in the placebo addition group (P<. 005). Seven (50%) of 14 patients who received open-label risperidone addition responded. Risperidone addition was superior to placebo in reducing OCD (P<.001), depressive (P<.001), and anxiety (P =.003) symptoms. There was no difference in response between OCD patients with and without comorbid diagnoses of chronic tic disorder or schizotypal personalty disorder. Other than mild, transient sedation, risperidone was well tolerated. CONCLUSION: These results suggest that OCD patients with and without comorbid chronic tic disorders or schizotypal personality disorder may respond to the addition of low-dose risperidone to ongoing SRI therapy.

Noradrenergic dysregulation during discontinuation of cocaine use in addicts.

BACKGROUND: The primary objective of the study was to prospectively determine possible noradrenergic dysregulation in cocaine addicts by assessing biochemical, behavioral, and cardiovascular responses to intravenous yohimbine hydrochloride during early and late discontinuation of cocaine use. METHODS: Twelve male and two female hospitalized cocaine-dependent subjects (mean +/- SD age, 30.9 +/- 7.3 years) who were not seeking primary treatment for addiction participated voluntarily for monetary remuneration. Following an initial test dose of intranasal cocaine, 2 mg/kg, cocaine addicts received single-blind, monitored cocaine insufflation, 2 mg/kg three times each day, for 3 consecutive days. One to two days (early discontinuation) and 15 to 16 days (late discontinuation) after the last dose of cocaine, subjects received double-blind, randomized intravenous infusions of yohimbine hydrochloride, 0.4 mg/kg, or placebo. Plasma 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) and plasma cortisol levels, anxiety-related symptoms on clinician- and subject-rated scales, blood pressure, and heart rate were measured throughout each test day. Ten of 14 subjects completed the entire study. RESULTS: Subjects had a significantly greater placebo-corrected MHPG response to yohimbine during early compared with late discontinuation. Subjects rated themselves significantly more nervous following yohimbine administration during early compared with late discontinuation. Seventy-one percent of subjects experienced a yohimbine-induced panic attack during early discontinuation compared with none during late discontinuation. CONCLUSIONS: The results of this study provide evidence of an underlying dysregulation in noradrenergic function and a vulnerability to panic anxiety during early discontinuation of cocaine use in addicts. Additional investigations of noradrenergic function appear warranted to further clarify derangements associated with cocaine addiction.

Haloperidol addition in fluvoxamine-refractory obsessive-compulsive disorder. A double-blind, placebo-controlled study in patients with and without tics.

BACKGROUND: To determine the efficacy of adding haloperidol to the treatment of patients with obsessive-compulsive disorder (OCD), with or without a comorbid chronic tic disorder, who were refractory to adequate treatment with the serotonin-uptake inhibitor fluvoxamine alone. It was hypothesized that OCD patients with a concurrent chronic tic disorder would preferentially respond to this treatment. METHODS: Sixty-two patients with a primary DSM-III-R diagnosis of OCD received placebo fluvoxamine for 1 week, followed by 8 weeks of active fluvoxamine. Thirty-four of these patients were refractory to fluvoxamine and were randomized in a double-blind fashion to 4 weeks of treatment with either haloperidol (n = 17) or placebo (n = 17) added to ongoing fluvoxamine treatment. The placebo-treated group included five women and 12 men, six inpatients and 11 outpatients, and eight patients with a comorbid chronic tic disorder. The haloperidol-treated group consisted of two women and 15 men, three inpatients and 14 outpatients, and seven patients with a comorbid chronic tic disorder. All 34 patients completed the entire study. The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Clinical Global Impression scale were the principal measures of treatment outcome. RESULTS: Haloperidol addition was significantly better than placebo in reducing the severity of obsessive-compulsive symptoms as measured by the Y-BOCS. Eleven of 17 patients responded to the haloperidol, compared with none of 17 patients given placebo. Eight of eight patients with comorbid chronic tic disorders, such as Tourette's disorder, responded to double-blind haloperidol addition to ongoing fluvoxamine treatment. Haloperidol addition was of little benefit in treating OCD patients without tics. Fluvoxamine blood levels were not related to treatment response. CONCLUSIONS: The results of this study suggest that OCD patients with a comorbid chronic tic disorder constitute a clinically meaningful subtype of OCD that might require conjoint serotonin-uptake inhibitor/neuroleptic therapy for effective symptom reduction.

Tryptophan depletion in patients with obsessive-compulsive disorder who respond to serotonin reuptake inhibitors.

METHODS: The effects of short-term tryptophan depletion were examined in 15 patients with DSM-III-R obsessive-compulsive disorder who had demonstrated symptom reduction following treatment with serotonin reuptake inhibitors. Patients received a 24-hour, low-tryptophan (160-mg/d) diet followed the next morning by a drink of 15 amino acids. A double-blind, placebo-controlled cross-over design was used. RESULTS: The diet and the amino acid drink reduced free plasma tryptophan levels by a mean of 84% 5 hours later. Short-term tryptophan depletion did not significantly change mean ratings of obsessions and compulsions. In contrast, mean depression ratings were significantly increased with tryptophan depletion compared with the control (tryptophan-supplemented) testing. CONCLUSION: Maintenance of serotonin reuptake inhibitor-induced improvement of obsessive and compulsive symptoms, unlike remission of depressive symptoms, may not depend on ongoing short-term availability of serotonin.

Effects of tryptophan depletion in drug-free adults with autistic disorder.

BACKGROUND: The primary objective of this study was to investigate the behavioral and biochemical responses to acute tryptophan depletion in drug-free adult patients with autistic disorder. METHODS: Twenty drug-free adults with autistic disorder (16 men and 4 women) (mean [+/- SD] age, 30.5 +/- 8.5 years) underwent short-term tryptophan depletion in a double-blind, placebo-controlled, randomized crossover design. Patients received a 24-hour, low-tryptophan diet followed the next morning by an amino acid drink. Behavioral ratings were obtained on the morning of the amino acid drink (baseline) and 180, 300, and 420 minutes after the drink. Plasma free and total tryptophan levels were obtained at baseline and 5 hours after the drink. The active and sham testing sessions were separated by 7 days. RESULTS: Eleven (65%) of the 17 patients who completed both test days showed a significant global worsening of behavioral symptoms with short-term tryptophan depletion, but none of the 17 patients showed any significant change in clinical status from baseline after sham depletion (P = .001). Tryptophan depletion led to a significant increase in behaviors such as whirling, flapping, pacing, banging and hitting self, rocking, and toe walking (P < .05). In addition, patients were significantly less calm and happy and more anxious. No significant change was observed in social relatedness or repetitive thoughts and behavior. Plasma total and free tryptophan levels were reduced 86% and 69%, respectively, 5 hours after the tryptophan-deficient amino acid drink. Patients who had a significant global exacerbation of symptoms had significantly higher baseline plasma total tryptophan levels (P < .001) and Autism Behavior Checklist scores (P = .005) than did patients who showed no significant change in symptoms after tryptophan depletion. CONCLUSIONS: The results of this study are consistent with previous research that has implicated a dysregulation in serotonin function in some patients with autism. These data suggest that the short-term reduction of serotonin precursor availability may exacerbate some symptoms characteristic of autism in some patients. Continued investigation into the role of serotonin in the pathogenesis and treatment of autistic disorder is warranted.

A double-blind, placebo-controlled study of fluvoxamine in adults with autistic disorder.

BACKGROUND: Autistic disorder is characterized by a fundamental disturbance in social interaction, impairments in communication, and a markedly restricted repertoire of activities and interests. Abnormalities in the serotonin neurotransmitter system have been identified in some persons with autism. No consistently effective and safe drugs have been developed for treating the symptoms of autism. METHODS: Thirty adults with autistic disorder completed a 12-week double-blind, placebo-controlled trial of the potent and selective serotonin uptake inhibitor fluvoxamine maleate. Behavioral ratings were obtained at baseline and after 4, 8, and 12 weeks of treatment. RESULTS: Eight (53%) of 15 patients in the fluvoxamine-treated group were categorized as responders compared with none of 15 in the placebo group (P = .001). Fluvoxamine was superior to placebo in reducing repetitive thoughts and behavior (P < .001), maladaptive behavior (P < .001), and aggression (P < .03), and in improving some aspects of social relatedness (P < .04), especially language usage (P < .008). Treatment response was not correlated with age level of autistic behavior, or full-scale IQ. Other than mild sedation and nausea in a few patients, fluvoxamine was well tolerated. No dyskinesias, adverse cardiovascular events, or seizures occurred. CONCLUSIONS: Fluvoxamine is more effective than placebo in the short-term treatment of the symptoms of autistic disorder in adults. Controlled studies of fluvoxamine and other potent and selective serotonin uptake inhibitors seem warranted in children and adolescents with autism.

A double-blind, placebo-controlled study of risperidone in adults with autistic disorder and other pervasive developmental disorders.

BACKGROUND: Neurobiological research has implicated the dopamine and serotonin systems in the pathogenesis of autism. Open-label reports suggest that the serotonin2A-dopamine D2 antagonist risperidone may be safe and effective in reducing the interfering symptoms of patients with autism. METHODS: Thirty-one adults (age [mean+/-SD], 28.1+/-7.3 years) with autistic disorder (n=17) or pervasive developmental disorder not otherwise specified (n=14) participated in a 12-week double-blind, placebo-controlled trial of risperidone. Patients treated with placebo subsequently received a 12-week open-label trial of risperidone. RESULTS: For persons completing the study, 8 (57%) of 14 patients treated with risperidone were categorized as responders (daily dose [mean+/-SD], 2.9+/-1.4 mg) compared with none of 16 in the placebo group (P<.002). Risperidone was superior to placebo in reducing repetitive behavior (P<.001), aggression (P<.001), anxiety or nervousness (P<.02), depression (P<.03), irritability (P<.01), and the overall behavioral symptoms of autism (P<.02). Objective, measurable change in social behavior and language did not occur. Nine (60%) of 15 patients who received treatment with open-label risperidone following the double-blind placebo phase responded. Other than mild, transient sedation, risperidone was well tolerated, with no evidence of extrapyramidal effects, cardiac events, or seizures. CONCLUSION: Risperidone is more effective than placebo in the short-term treatment of symptoms of autism in adults.

Elevated cerebrospinal fluid levels of oxytocin in obsessive-compulsive disorder. Comparison with Tourette's syndrome and healthy controls.

BACKGROUND: Limited neurobiological data have implicated central arginine vasopressin in the pathobiology of obsessive-compulsive disorder (OCD). Based on twin, family genetic, and pharmacological studies, some forms of OCD are etiologically related to Tourette's syndrome. The role of arginine vasopressin and related compounds such as oxytocin in Tourette's syndrome has not been previously explored. METHODS: To compare cerebrospinal fluid (CSF) levels of arginine vasopressin and oxytocin, we collected CSF at midday in a standardized fashion from a total of 83 individuals (29 patients with OCD, 23 patients with Tourette's syndrome, and 31 normal controls). We also collected family study data on each subject to determine which subjects had a family history positive for Tourette's syndrome, OCD, or related syndromes. RESULTS: In contrast to previous reports, we report similar concentrations of arginine vasopressin for all three groups but increased oxytocin levels in patients with OCD. Remarkably, this increase was observed only in a subset of patients with OCD (n = 22) independently identified as being without a personal or family history of tic disorders (P = .0003). In this subgroup of patients, the CSF oxytocin level was correlated with current severity of OCD (n = 19, r = .47, P < .05). CONCLUSIONS: A possible role for oxytocin in the neurobiology of a subtype of OCD is suggested by the elevated CSF levels of oxytocin and by the correlation between CSF oxytocin levels and OCD severity. These findings reinforce the value of family genetic data in identifying biologically homogeneous (and perhaps more etiologically homogeneous) groups of patients with OCD. Together with emerging pharmacological data showing differential responsiveness to treatment of tic-related OCD vs non-tic-related OCD, these data also argue strongly for the incorporation of tic-relatedness as a variable in biological and behavioral studies of patients with OCD.

Effects of acute tryptophan depletion on nocturnal melatonin secretion in humans.

Measurement of melatonin secretion throughout the night provides an index of net noradrenergic activity mediated by postsynaptic beta-adrenergic receptors in the pineal gland. Reduced melatonin secretion in some patients with depression might be related to reduced net noradrenergic function. However, a dysregulation in serotonin function has also been implicated in the pathophysiology of depression. The essential amino acid tryptophan is the precursor for both serotonin and melatonin production. To determine the effects of serotonin function on nocturnal melatonin secretion, eight healthy volunteers underwent active and sham tryptophan depletion in a randomized, double-blind fashion. Blood samples for melatonin and free and total tryptophan were obtained before and after the depletion. Acute tryptophan depletion decreased free and total plasma tryptophan levels to less than 20% of baseline levels. Melatonin secretion, expressed as area under the curve, was decreased in all eight subjects after tryptophan depletion when compared to sham depletion. These results suggest that reduced plasma tryptophan levels, and presumably brain serotonin concentrations, decrease nocturnal melatonin secretion in humans. Additional studies investigating the relationship between serotonin metabolism and pineal function in humans appear warranted.

Effects of catecholamine depletion with AMPT (alpha-methyl-para-tyrosine) in obsessive-compulsive disorder.

BACKGROUND: Several lines of evidence suggest that brain dopamine function may contribute to some obsessive-compulsive (OC) phenomena. The effects of catecholamine depletion were examined in drug-free patients with obsessive-compulsive disorder (OCD). METHODS: The tyrosine hydroxylase inhibitor alpha-methyl-para-tyrosine (AMPT) and diphenhydramine hydrochloride (placebo) were administered for three consecutive days, one week apart, to 6 drug-free adult OCD patients without a personal or family history of chronic tics, in a double-blind, randomized design. The effects of AMPT and placebo on OC, depression, anxiety and global clinical symptoms were assessed. RESULTS: AMPT produced no clinically or statistically significant change in any behavioral ratings, including OC symptom severity, compared with placebo. CONCLUSIONS: Acute reduction of catecholamine levels does not seem to affect OC symptoms in drug-free patients with OCD. Studies of catecholamine depletion with AMPT in patients with comorbid OCD and chronic tics may be of considerable neurobiological and clinical interest.

The neurobiology of tryptophan depletion in depression: effects of intravenous tryptophan infusion.

BACKGROUND: Previous work has suggested that acute depletion of the serotonin (5-HT) precursor tryptophan (TRP) causes transient compensatory changes in the 5-HT system that might be exploited for their antidepressant effects. In this study, neuroendocrine and mood responses to intravenous (i.v.) infusion of TRP were examined in order to evaluate central 5-HT function in depressed patients undergoing acute TRP depletion. METHODS: Thirty-eight drug-free patients with DSM-III-R major depression participated. Each patient underwent two randomized, double-blind TRP depletion tests, one sham and one active. At the estimated time of maximum TRP depletion, each patient received an i.v. infusion of TRP 100 mg/kg. Blood was obtained for serum cortisol, prolactin, and growth hormone. Mood was assessed using standardized rating scales. RESULTS: The cortisol response to i.v. TRP was significantly greater during TRP depletion than during sham depletion. Depressive symptoms showed a tendency to decrease after i.v. TRP following active, but not sham, TRP depletion. CONCLUSIONS: These findings are consistent with the present hypothesis and previous evidence that acute TRP depletion in drug-free depressed patients induces compensatory upregulation of postsynaptic 5-HT receptors. These changes are insufficient to serve as a means of effecting clinical improvement, but suggest that the antidepressant properties of rapid, marked manipulations of 5-HT function warrant further study.

m-Chlorophenylpiperazine in patients with obsessive-compulsive disorder: absence of symptom exacerbation.

Oral administration of the serotonin mixed agonist-antagonist meta-chlorophenylpiperazine (mCPP) at 0.5 mg/kg has been reported to exacerbate symptoms of obsessive-compulsive disorder (OCD). In an attempt to replicate these findings, double-blind behavioral and biochemical measures were obtained in 12 drug-free patients (9 men, 3 women) with OCD who received either oral mCPP (0.5 mg/kg), intravenous (IV) mCPP (0.1 mg/kg over 20 min), or placebo in random order on 3 separate test days. Neither oral nor IV mCPP had significant effects on the severity of OCD symptoms. The magnitude of the mCPP-induced plasma prolactin response and plasma mCPP levels were similar to those values obtained in other published studies in which mCPP exacerbated OCD symptoms. In contrast, both oral and IV mCPP were associated with significant increases in ratings of anxiety. These findings suggest that mCPP, whether administered by an oral or intravenous route (as a slow infusion), may not be a reliable probe for investigating obsessive-compulsive symptoms. It is possible, however, that more reproducible behavioral findings might be obtained by identifying susceptible subgroups of OCD or by including a behavioral exposure condition.

Addition of desipramine to serotonin reuptake inhibitors in treatment-resistant obsessive-compulsive disorder.

OBJECTIVE: The purpose of this study was to determine whether combined treatment with a selective serotonin reuptake inhibitor (SSRI) and a norepinephrine reuptake inhibitor, desipramine, effectively reduces obsessive-compulsive symptoms in patients who do not respond to SSRIs. METHOD: In a double-blind study, desipramine or placebo was added for 6 or 10 weeks to the treatment of 30 patients with obsessive-compulsive disorder whose symptoms were refractory to SSRI treatment (fluvoxamine, fluoxetine, or sertraline) alone. RESULTS: There were no significant differences between the adjunctive desipramine and placebo groups in obsessive-compulsive or depressive symptoms. CONCLUSIONS: These data suggest that clomipramine's possibly superior efficacy in the treatment of obsessive-compulsive symptoms may not stem from its capacity to inhibit reuptake of norepinephrine.

Neuroendocrine and behavioral responses to intravenous m-chlorophenylpiperazine (mCPP) in depressed patients and healthy comparison subjects.

OBJECTIVE: This double-blind study was undertaken to compare central serotonergic function in depressed patients and healthy comparison subjects by examining neuroendocrine and mood responses to intravenous infusion of the serotonin agonist m-chlorophenylpiperazine (mCPP). METHOD: The participants were 20 drug-free patients with DSM-III-R major depression and 18 healty comparison subjects. After an overnight fast, the subjects received an intravenous infusion of mCPP, 0.1 mg/kg, or placebo saline. Blood was obtained for measurement of serum prolactin, growth hormone (GH), and cortisol. Visual analogue scales were used to assess mood. RESULTS: The depressed patients had a blunted GH response and felt less drowsy than the comparison subjects; prolactin, cortisol, and the remaining behavioral ratings showed no differences between the two groups. CONCLUSIONS: In light of findings with other provocative agents, the blunted GH response to mCPP may reflect a defect in GH production in depression and could be a marker of the depressed state. The lack of differences in the other neuroendocrine variables suggests that the functioning of postsynaptic serotonergic receptors responsive to mCPP may be relatively intact in depression.

Neuroleptic addition in fluvoxamine-refractory obsessive-compulsive disorder.

Nine of 17 patients with obsessive-compulsive disorder responded when neuroleptic was added to fluvoxamine with or without lithium. Comorbid occurrence of tic spectrum disorders or of schizotypal personality disorder was associated with response. Abnormalities in brain dopamine and serotonin may be implicated in such patients.