Low serotonergic function and its normalization by treatment with sertraline in obsessive-compulsive disorder--an auditory evoked potential study

Perinatal Obsessive-Compulsive Disorder: Epidemiology, Phenomenology, Etiology, and Treatment

PURPOSE OF REVIEW

We review recent evidence concerning the epidemiology, etiology, and treatment of obsessive-compulsive disorder (OCD) in the perinatal period. We examine studies reporting on rates of both new-onset OCD and exacerbation in both pregnancy and postpartum; explore both biological and psychosocial risk factors for the disorder; and review the latest evidence concerning treatment.

RECENT FINDINGS

Evidence is limited in all areas, with rates of both OCD and subthreshold obsessive-compulsive symptoms varying widely across studies. Prevalence is likely higher in the perinatal period than in the general population. Clinical features in the perinatal period are more likely than at other times to concern harm to the child, with contamination and aggressive obsessions and cleaning and checking compulsions especially common. Research into the biological etiology is too limited at this time to be definitive. Both observational and randomized controlled trials support cognitive behavioral therapy with exposure and response prevention (CBT with ERP) as a first-line treatment, with limited evidence also supporting the use of selective serotonin reuptake inhibitors (SSRIs). Treatment considerations in the perinatal period must weigh the risks of treatment vs. the risks of untreated illness. Perinatal OCD is common and can be impairing. Clinical features differ somewhat compared to non-perinatal periods. Treatment does not differ from that used in the general population, though evidence pertaining specifically to the perinatal period is sparse.

Serotonin: from sensory processing to schizophrenia using an electrophysiological method

Serotonin plays a major role in sensory processing especially with in the primary auditory cortex. The so-called loudness dependence of auditory evoked potentials is generated by pyramidal cells of the primary auditory cortex (LDAEP) which are modulated by serotonergic projection fibers to the main regulators of pyramidal cells, i.e. GABAergic interneurons. Therefore, there are a lot of preclinical as well as clinical proofs and hints that the LDAEP may serve as a valid indicator of synaptically released serotonin, although there are also data not supporting this relationship. This is further examplified by LDAEP data in patients with different states of schizophrenia, from prodromal to the chronic state. Hereby, a strong relationship was found between LDAEP, i.e. different serotonin levels, and the negative symptoms of these groups of patients with schizophrenia. This underlines the importance of LDAEP as indicator of central serotonergic neurotransmission and its high relevance for clinical psychiatry and psychopharmacology.

Transcranial sonography in obsessive-compulsive disorder

There is convergent evidence that basal ganglia structures are involved in the pathogenesis of obsessive-compulsive disorder (OCD). It has been also assumed that OCD is caused by a central serotonergic dysfunction. Transcranial sonography (TCS) has become a reliable, sensitive and non-invasive diagnostic tool concerning the evaluation of extrapyramidal movement disorders. This study used TCS to examine the alterations in different parenchymal regions, especially concerning serotonergic brainstem raphe nuclei as well as basal ganglia in OCD. Thirty-one OCD patients were compared with 31 matched healthy controls. Echogenecities were investigated according to the examination protocol for extrapyramidal disorders using a Siemens Sonoline(®) Elegra system. Obsessive-compulsive disorder patients showed reduced echogenity of the serotonergic brainstem raphe nuclei (32.3%) compared with healthy controls (16.1%). In nine OCD-patients (31%), but only in 2 control subjects (6.2%), a hyperechogenicity of the caudate nucleus was found. Patients with OCD significantly more often reveal a hypoechogenic brainstem raphe possibly reflecting altered serotonergic neurons there and a hyperechogenicity of caudate nucleus indicating structural or molecular cell changes. Further research is warranted to examine, whether TCS is useful in order to classify OCD and its subtypes.

The loudness dependence of auditory evoked potentials and effects of psychopathology and psychopharmacotherapy in psychiatric inpatients

OBJECTIVE

Many studies have provided evidence for the loudness dependence of auditory evoked potentials (LDAEP) as a marker for central serotonergic activity but remained inconclusive for its suitability in clinical use.

METHODS

A cross-sectional sample of 162 psychiatric inpatients (major depression N = 86, bipolar disorder N = 12, schizophrenia N = 50, and schizoaffective disorder N = 14) and 40 healthy subjects was retrospectively examined for LDAEP and effects of psychopathology and psychopharmacology.

RESULTS

The LDAEP was weaker in patients with affective disorders than in healthy subjects but did not differentiate between the total patient sample and healthy controls. LDAEP correlated significantly with dimensions of the Brief Symptom Inventory in the total patient sample (depression, paranoid ideation, psychoticism, Global Symptom Index, and Positive Symptom Distress Index), in patients with affective disorders (depression) and with schizophrenia spectrum disorders (depression, psychoticism, Global Symptom Index, and Positive Symptom Distress Index). Similar correlations were found in depressed patients with a single noradrenergic and specific serotonergic antidepressant or serotonin-norepinephrine reuptake inhibitor. There was a negative correlation between dosage of typical antipsychotics and LDAEP. Hypnotics generally led to a lower LDAEP.

CONCLUSION

The LDAEP in patients is related to severity of psychopathologic syndromes irrespective of diagnosis. Chronic psychopharmacologic treatment may also differentially modulate the LDAEP, but longitudinal studies are needed.