The Role of Psychiatry for Transgender and Gender Diverse Adults

ABSTRACT

Since the inclusion of gender identity disorder in the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III), psychiatry and the broader medical field have made substantial alterations in their recognition of and respect for transgender and gender diverse (TGD) identities. As this recognition continues to expand, psychiatrists should be aware of both historical harm and current best care practices, especially in light of psychiatric morbidity in TGD populations relative to the general population. This article contextualizes the history of psychiatry's engagement with TGD patients and presents the gender minority stress and resilience model to frame the mental health disparities experienced by TGD people. We envision a role for psychiatry that goes beyond gatekeeping gender-affirming hormone therapy and surgeries. Instead, we should invest in equitable care across the continuum of mental health needs. We provide an overview of existing literature to help characterize psychiatric epidemiology for this population, with the goal of offering guidance on how psychiatrists can deliver responsive and high-quality care for TGD people. Some key areas of proposed clinical improvement include culturally tailoring interventions for substance use disorders, reducing medical trauma in acute psychiatric care settings, and better understanding the interplay of psychopharmacology and gender-affirming hormone therapy.

Error-related Alpha Suppression: Scalp Topography and (Lack of) Modulation by Modafinil

Errors in performance trigger cognitive and neural changes that are implemented to adaptively adjust to fluctuating demands. Error-related alpha suppression (ERAS)-which refers to decreased power in the alpha frequency band after an incorrect response-is thought to reflect cognitive arousal after errors. Much of this work has been correlational, however, and there are no direct investigations into its pharmacological sensitivity. In Study 1 (n = 61), we evaluated the presence and scalp distribution of ERAS in a novel flanker task specifically developed for cross-species assessments. Using this same task in Study 2 (n = 26), which had a placebo-controlled within-subject design, we evaluated the sensitivity of ERAS to placebo (0 mg), low (100 mg), and high (200 mg) doses of modafinil, a wakefulness promoting agent. Consistent with previous work, ERAS was maximal at parieto-occipital recording sites in both studies. In Study 2, modafinil did not have strong effects on ERAS (a significant Accuracy × Dose interaction emerged, but drug-placebo differences did not reach statistical significance after correction for multiple comparisons and was absent after controlling for accuracy rate). ERAS was correlated with accuracy rates in both studies. Thus, modafinil did not impact ERAS as hypothesized, and findings indicate ERAS may reflect an orienting response to infrequent events.

A multi-pronged investigation of option generation using depression, PET and modafinil

Option generation is a critical process in decision making, but previous studies have largely focused on choices between options given by a researcher. Consequently, how we self-generate options for behaviour remain poorly understood. Here, we investigated option generation in major depressive disorder and how dopamine might modulate this process, as well as the effects of modafinil (a putative cognitive enhancer) on option generation in healthy individuals. We first compared differences in self-generated options between healthy non-depressed adults [n = 44, age = 26.3 years (SD 5.9)] and patients with major depressive disorder [n = 54, age = 24.8 years (SD 7.4)]. In the second study, a subset of depressed individuals [n = 22, age = 25.6 years (SD 7.8)] underwent PET scans with 11C-raclopride to examine the relationships between dopamine D2/D3 receptor availability and individual differences in option generation. Finally, a randomized, double-blind, placebo-controlled, three-way crossover study of modafinil (100 mg and 200 mg), was conducted in an independent sample of healthy people [n = 19, age = 23.2 years (SD 4.8)] to compare option generation under different doses of this drug. The first study revealed that patients with major depressive disorder produced significantly fewer options [t(96) = 2.68, P = 0.009, Cohen's d = 0.54], albeit with greater uniqueness [t(96) = -2.54, P = 0.01, Cohen's d = 0.52], on the option generation task compared to healthy controls. In the second study, we found that 11C-raclopride binding potential in the putamen was negatively correlated with fluency (r = -0.69, P = 0.001) but positively associated with uniqueness (r = 0.59, P = 0.007). Hence, depressed individuals with higher densities of unoccupied putamen D2/D3 receptors in the putamen generated fewer but more unique options, whereas patients with lower D2/D3 receptor availability were likely to produce a larger number of similar options. Finally, healthy participants were less unique [F(2,36) = 3.32, P = 0.048, partial η2 = 0.16] and diverse [F(2,36) = 4.31, P = 0.021, partial η2 = 0.19] after taking 200 mg versus 100 mg and 0 mg of modafinil, while fluency increased linearly with dosage at a trend level [F(1,18) = 4.11, P = 0.058, partial η2 = 0.19]. Our results show, for the first time, that option generation is affected in clinical depression and that dopaminergic activity in the putamen of patients with major depressive disorder may play a key role in the self-generation of options. Modafinil was also found to influence option generation in healthy people by reducing the creativity of options produced.

Concordant neurophysiological signatures of cognitive control in humans and rats

Progress towards understanding neural mechanisms in humans relevant to psychiatric conditions has been hindered by a lack of translationally-relevant cognitive tasks for laboratory animals. Accordingly, there is a critical need to develop parallel neurophysiological assessments of domains of cognition, such as cognitive control, in humans and laboratory animals. To address this, we developed a touchscreen-based cognitive (Eriksen Flanker) task in rats and used its key characteristics to construct a novel human version, with similar testing parameters and endpoints across species. We obtained continuous electroencephalogram (EEG) recordings, including local field potentials in rats, and compared electrophysiological signatures locked to stimulus onset and responses across species. We also assessed whether behavioral or physiological task effects were modulated by modafinil, which enhances aspects of cognitive function in humans. In both species, the task elicited expected flanker interference effects (reduced accuracy) during high-conflict trials. Across homologous neuroanatomical loci, stimulus-locked increases in theta power during high-conflict trials as well as error-related negative potentials were observed. These endpoints were not affected by modafinil in either species. Despite some species-specific patterns, our findings demonstrate the feasibility of a rat Flanker task as well as cross-species behavioral and neurophysiological similarities, which may enable novel insights into the neural correlates of healthy and aberrant behavior and provide mechanistic insights relevant to treatment.

Differential trajectories of neurocognitive functioning in females versus males following treatment for pediatric brain tumors

BACKGROUND

Female and male trajectories of cerebellar and lobar brain structures are sexually dimorphic, making sex a potential candidate moderator of neurocognitive late effects from radiation treatment. We sought to evaluate longitudinal neurocognitive functioning in male versus female children treated for posterior fossa brain tumors.

METHODS

Fifty-one female and 63 male survivors of posterior fossa tumors completed neuropsychological testing at 2 timepoints. We included patients treated with surgical resection, chemotherapy, and radiation therapy. Multilevel mixed modeling was used to predict IQ score as a function of patient sex following treatment (~2 or ~4 years post treatment). Effect sizes were used as a measure of clinical significance.

RESULTS

Multilevel models resulted in a significant sex by time interaction (F = 6.69, P = 0.011). Females' cognitive scores were considerably higher compared with males at 4 years posttreatment. Females demonstrated an average improvement of 7.61 standard score IQ points compared with a decline of 2.97 points for males at 4 years follow-up. Effect sizes for female IQ compared with male IQ at 4 years posttreatment were between 0.8 and 0.9.

CONCLUSION

Trajectories of neurocognitive functioning following posterior fossa tumor treatment differed between female and male children. Sexual dimorphism in radiation late effects may alter treatment decisions in children. Research into sex-specific neuroprotective mechanisms underlying neurocognitive development following pediatric brain tumor treatments is warranted.

Optimizing assessments of post-error slowing: A neurobehavioral investigation of a flanker task

Appropriately adjusting to errors is essential for adaptive behavior. Post-error slowing (PES) refers to the increased reaction times on trials following incorrect relative to correct responses. PES has been used as a metric of cognitive control in basic cognitive neuroscience research as well as clinical contexts. However, calculation of PES varies widely among studies and has not yet been standardized, despite recent calls to optimize its measurement. Here, using behavioral and electrophysiological data from a modified flanker task, we considered different methods of calculating PES, assessed their internal consistency, examined their convergent correlations with behavioral performance and error-related event-related brain potentials (ERPs), and evaluated their sensitivity to task demands (e.g., presence of trial-to-trial feedback). Results indicated that the so-called robust measure of PES, calculated using only error-surrounding trials, provided an estimate of PES that was three times larger in magnitude than the traditional calculation. This robust PES correlated with the amplitude of the error positivity (Pe), an index of attention allocation to errors, just as well as the traditional method. However, all PES estimates had very weak internal consistency. Implications for measurement are discussed.