The combination of escitalopram and aripiprazole: Investigation of psychomotor effects in rats

Effect of aripiprazole on promoting cognitive function and enhancing clinical efficacy in patients with first-episode depression on escitalopram: A randomized controlled trial

OBJECTIVES

To explore the effect of escitalopram combined with aripiprazole on cognitive function in patients with major depressive disorder (MDD), and to evaluate the clinical efficacy of the combination therapy.

METHOD

A total of 70 patients with first-episode MDD were randomly divided into the study group or the control group, receiving escitalopram combined with aripiprazole (5 mg/day) or escitalopram monotherapy respectively for 8 weeks. The severity of illness was assessed by using the Hamilton Rating Scale for Depression (HAMD) at baseline, at the end of 4th and 8th week, and cognitive function was assessed by using the THINC integrated tool (THINC-it), the Wisconsin Card Sorting Test (WCST), and the Continuous Performance Test (CPT). Rating Scale for Extrapyramidal Side Effects (RSESE) was applied to assess adverse reactions.

RESULTS

The average HAMD-17 and HAMA scores decreased over time in both the control and the study groups, but the reductions were not statistically different between two groups with the passage of time. In WCST, total number of response (TR) of the study group decreased relative to the baseline at the end of the eighth week, but the control group did not significantly change during whole eight weeks. Perseverative errors (PE) in the control group eventually decreased at the end of Week 8 compared to that at Week 4, but in the study group, it was a continuous trend of decrease. In CPT, the decrease of leakage responses (LR) in the study group was higher than that of the control group in 2-digit number, and LR of the control group was higher than that of the study group at the end of Week 8 in 4-digit number. The downtrend of LR in 4-digit number kept for the whole period in study group, while in the control group, the LR did not decrease significantly until the end of Week 8 compared to that at baseline.

CONCLUSION

Escitalopram combined with a low-dose of aripiprazole, and escitalopram monotherapy could both enhance cognitive function of MDD patients, while the improvements of combination therapy might happen relatively earlier. The combined use of escitalopram and aripiprazole might be more beneficial to the domains of executive function (EF) and continuous attention compared to escitalopram monotherapy. There was no significant differences between two treatment options in alleviating depressive and anxiety symptoms.

Haloperidol and aripiprazole impact on the BDNF and glucocorticoid receptor levels in the rat hippocampus and prefrontal cortex: effect of the chronic mild stress

Objective. Changes in the brain derived neurotrophic factor (BDNF) and glucocorticoid receptor (GR) expression in the prefrontal cortex (PFC) and hippocampus (HIP) are associated with psychiatric diseases and stress response. Chronic mild stress (CMS) may alter BDNF as well as GR levels in both the PFC and the HIP. The aim of the present study was to find out whether chronic treatment with a typical antipsychotic haloperidol (HAL) and an atypical antipsychotic aripiprazole (ARI) may modify the CMS effect on the BDNF and GR expression in the above-mentioned structures. Methods. The rats were exposed to CMS for 3 weeks and from the 7^th day of CMS injected with vehicle (VEH), HAL (1 mg/kg) or ARI (10 mg/kg) for 4 weeks. BDNF and GR mRNA levels were established in the PFC and the HIP by Real Time PCR, whereas, PFC and HIP samples were obtained by punching them from 500 µm thick frozen sections. C-Fos immunoreactivity was analyzed in the PFC and the HIP on 30 µm thick paraformaldehyde fixed sections. Weight gain and corticosterone (CORT) levels were also measured. Results. The CMS and HAL suppressed the BDNF and GR mRNA levels in the PFC. In the HIP, CMS elevated BDNF mRNA levels that were suppressed by HAL and ARI treatments. The CMS decreased the c-Fos immunoreactivity in the PFC in both HAL- and ARI-treated animals. In the HIP, HAL increased the c-Fos immunoreactivity that was again diminished in animals exposed to CMS. Stressed animals gained markedly less weight until the 7^th day of CMS, however, later their weight gain did not differ from the unstressed ones or was even higher in CMS+HAL group. Un-stressed HAL and ARI animals gained less weight than the VEH ones. Neither CMS nor HAL/ARI affected the plasma CORT levels. Conclusion. The present data indicate that HAL and ARI in the doses 1 mg/kg or 10 mg/kg, respectively, does not modify the effect of the CMS preconditioning on the BDNF and GR mRNA levels in the PFC or the HIP. However, HAL seems to modify the CMS effect on the HIP activation.

Effects of combined escitalopram and aripiprazole in rats: role of the 5-HT1a receptor

RATIONALE

Pre-clinical and clinical studies have suggested that the antidepressant efficacy of escitalopram (ESC) can be augmented by co-administration of aripiprazole (ARI).

OBJECTIVE

To establish if the effects of ESC + ARI can be altered by modulating the 5-HT_1a receptor.

METHODS

Sprague-Dawley male rats received ESC + ARI (10 and 2 mg/kg/day, respectively, via osmotic or by cumulative injections), as well as the 5-HT_1a antagonist WAY-100635 (WAY; 0.01-1 mg/kg) and the 5-HT_1a agonist 8-OH-DPAT (DPAT; 0.3-1 mg/kg) prior to testing in locomotion chambers and in the forced swim test (FST). Expression of the 5-HT_1a receptor mRNA in the dorsal raphe nucleus, hippocampus, septum, and entorhinal cortex was also assessed.

RESULTS

WAY generally synergized, while DPAT antagonized, the effect of ESC + ARI on motor activity. All groups showed significantly lower 5-HT_1a mRNA in the dorsal raphe nucleus. In the hippocampus, ESC + ARI and WAY + ESC + ARI groups displayed equivalent elevations of 5-HT_1a mRNA, but this was not observed in groups that received DPAT + ESC + ARI. Finally, the addition of ARI to ESC augmented the effect that ESC alone had on reducing immobility in the FST. Importantly, WAY antagonized this effect, while DPAT had no consequences.

CONCLUSIONS

Taken together, these results in rats indicate that the 5-HT_1a receptor is involved in the behavioral and brain region-specific mRNA effects of ESC + ARI.