Quetiapine-Induced Hypomania and its Association with Quetiapine/Norquetiapine Plasma Concentrations: A Case Series of Bipolar Type 2 Patients

Atypical antipsychotic-induced mania: A systematic review and meta-analysis

BACKGROUND

The possibility of atypical antipsychotics (AA) to induce manic symptoms has been raised by several articles. The objective of this study was to describe whether exposure to AA may induce mania in mood disorders.

METHODS

We performed a systematic review following the preferred reporting items for systematic reviews and meta-analysis guidelines. The systematic search encompassed all relevant studies published until April 4th, 2022. A meta-analysis testing whether treatment emergent mania (TEM) is more frequent with the use of AA compared with placebo was performed.

RESULTS

A total of 52 studies were included in the systematic review. We found 24 case reports or case series describing 40 manic/hypomanic episodes allegedly induced by AA. Twenty-one placebo-controlled trials were included in a meta-analysis including 4823 individuals treated with AA and 3252 individuals receiving placebo. Our meta-analysis showed that the use of AA protects against the development of TEM (OR: 0.68 [95 % CI: 0.52-0.89], p = 0.005).

LIMITATIONS

AA-induced mania/hypomania was not the primary outcome in any of the observational or interventional studies. TEM was not homogeneously defined across studies. In most case reports it was not possible to establish causality between the use of AA and the development of manic symptoms.

CONCLUSIONS

TEM is more frequent with placebo than with AA, which suggests that AA exposure does not represent a relevant risk for TEM. Mania/hypomania induced by an AA seems to be rare events, since anecdotal evidence from case reports and case series were not observed in observational prospective and interventional studies.

β2 and α2 adrenergic receptors mediate the proneurogenic in vitro effects of norquetiapine

Positive modulation of adult hippocampal neurogenesis may contribute to the therapeutic effects of clinically relevant antidepressant drugs, including atypical antipsychotics. Quetiapine, an antipsychotic which represents a therapeutic option in patients who are resistant to classical antidepressants, promotes adult hippocampal neurogenesis in preclinical studies. Norquetiapine, the key active metabolite of quetiapine in humans, has a distinctive receptor profile than the parent compound. The drug is indeed a high affinity norepinephrine transporter inhibitor and such activity has been proposed to contribute to its antidepressant effect. At present, no information is available on the effects of norquetiapine on adult neurogenesis. We extensively investigated the activity of quetiapine and norquetiapine on adult murine neural stem/progenitor cells and their progeny. Additionally, selective antagonists for β₂/α₂ adrenergic receptors allowed us to evaluate if these receptors could mediate quetiapine and norquetiapine effects. We demonstrated that both drugs elicit in vitro proneurogenic effects but also that norquetiapine had distinctive properties which may depend on its ability to inhibit norepinephrine transporter and involve β₂/α₂ adrenergic receptors. Animal care and experimental procedures were approved by the Institutional Animal Care and Use Committees (IACUC) at University of Piemonte Orientale, Italy (approval No. 1033/2015PR) on September 29, 2015.