Investigating interactive effects of worry and the catechol-o-methyltransferase gene (COMT) on working memory performance

The Catechol O-Methyltransferase Inhibitor Entacapone in the Treatment of Parkinson's Disease: Personal Reflections on a First-in-Class Drug Development Programme 40 Years On

In the 1980s, Orion Pharma, then a mid-ranking Nordic area pharmaceutical company, established a drug development programme on the inhibition of catechol O-methyltransferase (COMT). This enzyme, which plays an important role in the inactivation of catecholamine neurotransmitters and drugs with a catechol structure, thus came under consideration as a target in the innovative translational and clinical programme we describe in this historical review. The starting point was the conjecture that a peripherally acting COMT inhibitor might improve entry of levodopa into the brain. This had potentially significant implications for the medical treatment of Parkinson's disease (PD). The rationale was that more efficient delivery of levodopa to the brain might allow the high therapeutic doses of levodopa to be reduced and the dose interval to be extended. Elucidation of structure-activity relations paved the way for the discovery and development of entacapone, a 5-nitrocatechol that was a potent and highly specific inhibitor of COMT. Experience in phase III clinical trials established that entacapone, used as an adjunct to regular or controlled-release levodopa preparations (also including a peripherally acting dopa-decarboxylase inhibitor), increased ON-time and reduced OFF-time and improved clinical condition in patients with PD experiencing wearing-off, often with a reduced daily levodopa dose. Several of these studies also identified that entacapone improved patients' quality of life and was cost-effective. Subsequently, entacapone has been amalgamated into a triple-combination preparation (Stalevo®) with levodopa and carbidopa to create a flexible and convenient drug therapy for patients with PD who have end-of-dose motor fluctuations not stabilised on levodopa/dopa-decarboxylase inhibitor treatment. This review offers a historical perspective on a successful programme of drug development by researchers who played central roles in the progress from exploratory hypothesis to registered pharmaceutical product.

Estradiol and the Catechol-o-methyltransferase Gene Interact to Predict Working Memory Performance: A Replication and Extension

Decades of evidence across taxa have established the importance of dopamine (DA) signaling in the pFC for successful working memory performance. Genetic and hormonal factors can shape individual differences in prefrontal DA tone. The catechol-o-methyltransferase (COMT) gene regulates basal prefrontal DA, and the sex hormone 17β-estradiol potentiates DA release. E. Jacobs and M. D'Esposito [Estrogen shapes dopamine-dependent cognitive processes: Implications for women's health. Journal of Neuroscience, 31, 5286-5293, 2011] investigated the moderating role of estradiol on cognition using the COMT gene and COMT enzymatic activity as a proxy for pFC DA tone. They found that increases in 17β-estradiol within women at two time points during the menstrual cycle influenced working memory performance in a COMT-dependent manner. Here, we aimed to replicate and extend the behavioral findings of Jacobs and D'Esposito by employing an intensive repeated-measures design across a full menstrual cycle. Our results replicated the original investigation. Within-person increases in estradiol were associated with improved performance on 2-back lure trials for participants with low basal levels of DA (Val/Val carriers). The association was in the opposite direction for participants with higher basal levels of DA (Met/Met carriers). Our findings support the role of estrogen in DA-related cognitive functions and further highlight the need to consider gonadal hormones in cognitive science research.

Examining a window of vulnerability for affective symptoms in the mid-luteal phase of the menstrual cycle

Particular phases of the menstrual cycle may exacerbate affective symptoms for females with a diagnosed mental health disorder. However, there are mixed findings regarding whether affective symptoms change across the menstrual cycle in females without a clinical diagnosis. The window of vulnerability model proposes that natural increases in ovarian hormones in the mid-luteal phase of the menstrual cycle lead to systematic changes in brain networks associated with affective processing. Consequently, the model posits that females may experience stress more intensely and remember negative events more readily in the mid-luteal phase, increasing their risk for higher affective symptoms. Using a 35-day longitudinal study design, we tested the window of vulnerability model in a non-clinical sample. We tracked naturally cycling females' daily stress and three types of affective symptoms: anxious apprehension, anxious arousal, and anhedonic depression. Using multilevel modeling, we simultaneously modeled within- and between-person associations among stress and menstrual phase for each affective symptom. We found increased anhedonic depression in the mid-luteal phase but not anxious apprehension or anxious arousal. Moreover, we detected a positive association between within- and between-person stress and anxious apprehension and anhedonic depression, but not anxious arousal. These associations were not stronger in the mid-luteal phase. Overall, we provide weak evidence for a window of vulnerability for affective symptoms in the mid-luteal phase of the menstrual cycle. Our findings suggest that stress is a better predictor of fluctuations in affective symptoms than the menstrual cycle. Moreover, our findings highlight the importance of measuring multiple negative affective symptoms because they may be differentially related to stress and the menstrual cycle.