Pharmacoepidemiology of psychotropic drugs: examples of current research challenges on major public health issues

[Genotoxicity of psychotropic drugs in experimental and clinical studies]

The analysis of experimental data on the study of the genotoxic activity of psychotropic drugs published over the past 25 years has been carried out. It has been shown that the information describing the genotoxicity of psychotropic drugs is characterized by fragmentation, contradictions, and the conditions for their experimental production often do not meet modern requirements. Conclusions about the presence or absence of genotoxic properties can be made only for 9.6% 94 examined drugs. The need for a large-scale systematic reassessment of the genotoxicity of psychotropic drugs, especially drugs of the first generation, on the basis of modern methodology, including studies of mutagen-modifying activity, has been proven. The expediency of monitoring the genotoxic status of patients receiving psychotropic drugs is emphasized, which should contribute to an adequate assessment of the genotoxic risk of their use and objectification of approaches when choosing a drug for the safe therapy. The urgency of conducting research to determine the role of primary DNA damage in the pathogenesis of mental illnesses has been substantiated.

Safety of psychotropic medicines: contribution from observational evidence

The risks associated with psychotropic drugs use should be accurately documented at the population level in view of the growing number of persons exposed to these drugs. The strengths of observational studies regarding the identification of drug-related harms mirror the limitations of randomised controlled trials and vice-versa. Observational studies can be carried out in large samples of unselected participants treated in real-life conditions and who may be followed up over long periods. Serious adverse effects undetected during pre-marketing clinical trials may be observed only in post-marketing use, such as metabolic effects of second-generation antipsychotics. Observational studies play a key role in the identification of teratogenic risks, such as those induced by prenatal exposure to anticonvulsants. These studies are the main source of information to investigate the long-term effects of drugs, such as the possible increased risk of dementia in benzodiazepine users. They may also contribute to the accurate assessment at population level of risks overestimated by studies carried out in non-representative samples, such as the risk of congenital heart diseases in babies prenatally exposed to lithium. Owing to the lack of random allocation of drugs, confounding by indication or by disease severity are the major sources of biases in observational studies exploring drug safety. An adverse outcome may be wrongly imputed to drug exposure while it is a symptom/outcome of the disease motivating the decision to prescribe. Such a bias may occur in studies investigating the link between exposure to antidepressants and suicidality. As several methods have been developed to lessen the impact of such biases, pharmaco-epidemiological studies based upon stringent methodological designs should be regarded as a valid approach for assessing psychotropic drug safety.

Antipsychotic prescribing in youths: a French community-based study from 2006 to 2013

The objectives were to explore in a community-based sample of persons aged 0-25 years: (1) trends in antipsychotic prescribing, (2) characteristics of the zone of residence associated with antipsychotic prescribing rates, and (3) the pattern of antipsychotic prescribing. The study was performed using reimbursement data from the French Insurance Healthcare system. Prescribing trends were investigated over the period 2006-2013. An ecological design was used to assess the impact of the socio-economical and health resource characteristics of the zone of residence (n = 96 administrative subdivisions of French territory) on antipsychotic prescribing rates. The pattern of antipsychotic prescribing was explored in a cohort of youths newly treated with antipsychotics. Over the period 2006-2013, antipsychotic dispensing rates were stable in persons aged 0-25 years (4.8 per 1,000 in 2006 and 4.9 per 1,000 in 2013). First-generation antipsychotic dispensing rates decreased from 3.1 to 2.6 per 1,000 (OR = 0.96, 95% CI 0.94-0.98), while second-generation antipsychotic dispensing rates increased from 2.7 to 3.4 per 1,000 (OR = 1.03, 95% CI 1.01-1.05). Antipsychotic prescribing rates were impacted by health resource characteristics of the zone of residence in children aged 10 years and under and by socio-economical characteristics in those aged 16-20 years. In all the age groups, antipsychotics were principally started by hospital practitioners (47%) and general practitioners (34%). The rates of psychostimulants concomitantly prescribed with antipsychotics were lower than 5%. In conclusion, rates of youths exposed to second-generation antipsychotics are still rising. The impact of environmental characteristics on antipsychotics prescribing and appropriateness of these prescriptions in youths should be further investigated.

Hypothalamus-anchored resting brain network changes before and after sertraline treatment in major depression

Sertraline, one of the oldest antidepressants, remains to be the most efficacious treatment for depression. However, major depression disorder (MDD) is characterized by altered emotion processing and deficits in cognitive control. In cognitive interference tasks, patients with MDD have shown excessive hypothalamus activity. The purpose of this study was to examine the effects of antidepressant treatment (sertraline) on hypothalamus-anchored resting brain circuitry. Functional magnetic resonance imaging was conducted on depressed patients (n=12) both before and after antidepressant treatment. After eight weeks of antidepressant treatment, patients with depression showed significantly increased connectivity between the hypothalamus and dorsolateral prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex, insula, putamen, caudate, and claustrum. By contrast, decreased connectivity of the hypothalamus-related areas was primarily located in the inferior frontal gyrus, medial frontal gyrus, cingulated gyrus, precuneus, thalamus, and cerebellum. After eight weeks of antidepressant therapy, 8 out of the 12 depressed subjects achieved 70% reduction or better in depressive symptoms, as measured on the Hamilton depression rating scale. Our findings may infer that antidepressant treatment can alter the functional connectivity of the hypothalamus resting brain to achieve its therapeutic effect.

The effects of antidepressants on human brain as detected by imaging studies. Focus on major depression

Recent brain imaging studies have shed light on understanding the pathogenesis of mood disorders. Evidence of structural, chemical, and functional brain changes, particularly in prefrontal cortex, cingulate, and amygdala, has been revealed in major depressive disorder (MDD). Furthermore, imaging techniques have been applied to monitor the effects of antidepressants (ADs) both in the brains of healthy volunteers and MDD patients. Although with some discrepancies due to the differences in study designs and patient samples, imaging findings have shown that ADs, particularly those having effects on the serotonergic system, modulate the volumes, functions and biochemistry of brain structures, i.e. dorsolateral prefrontal cortex, anterior cingulate and amygdala, which have been demonstrated abnormal in MDD by earlier imaging studies. This paper reviews imaging studies conducted in MDD patients and healthy controls treated with different ADs.

Antipsychotic utilisation and polypharmacy in Italian residential facilities: a survey

OBJECTIVE

To evaluate the prescribing practices in psychiatric residential facilities, with particular focus both on the antipsychotic dose and polypharmacy as well as the variation of antipsychotic patterns during a patient's stay within the facilities.

METHODS

Fifteen residential facilities of Liguria region in Italy were included. Data were collected through a chart review during a one-day census. Frequency of psychotropic patterns was estimated. Different non-parametric tests were used to analyse the changes in prescription patterns as well as the relationship among antipsychotic dose, the number of antipsychotics and anticholinergic use.

RESULTS

The study sample includes 362 patients, 61.9% males. On the census day 77.5% of patients received psychotropic polypharmacy and 57.2% antipsychotic polypharmacy. Antipsychotic polypharmacy was related to the total antipsychotic daily dose and to anticholinergic use. A trend towards an increase of antipsychotic and psychotropic polypharmacy and higher doses of antipsychotics over the period of stay within the facilities was noted. This tendency was related to the length of stay in the facility.

CONCLUSIONS

Compared to earlier studies in the same clinical environment a significant increase in the use of psychotropic and antipsychotic polypharmacy was observed. The risk of prescribed polypharmacy seems to be related to time spent in the facility.