It is well-known that attention deficit hyperactivity disorder (ADHD) is associated with changes in the dopaminergic system. However, the relationship between central dopaminergic tone and the blood oxygen level-dependent (BOLD) signal during receipt of rewards and penalties in the corticostriatal pathway in adults with ADHD is unclear.

Single-photon emission computed tomography with [99mTC]TRODAT-1 was used to assess striatal dopamine transporter (DAT) availability. Event-related functional magnetic resonance imaging was conducted on subjects performing the Iowa Gambling Test.

DAT availability was found to be associated with the BOLD response, which was a covariate of monetary loss, in the medial prefrontal cortex (r = 0.55, P = .03), right ventral striatum (r = 0.69, P = .003), and right orbital frontal cortex (r = 0.53, P = .03) in adults with ADHD. However, a similar correlation was not found in the controls.

The results confirmed that dopaminergic tone may play a different role in the penalty-elicited response of adults with ADHD. It is plausible that a lower neuro-threshold accompanied by insensitivity to punishment could be exacerbated by the hypodopaminergic tone in ADHD.

This study investigates the effect of sex and childhood trauma on affective processing in bipolar disorder (BPD) patients.

In a sample of fifty-six BPD patients, we administered the Childhood Trauma Questionnaire (CTQ), and the Iowa Gambling Task (IGT) and the Affective Go/No-Go (AGNG) to measure affective processing. Analysis of Variance (ANOVA) was used to evaluate the effect of sex and childhood trauma on IGT; Repeated-Measures ANOVAs to measure accuracy and bias measures across conditions on the AGNG.

In the context of childhood abuse, females evidenced a more conservative cognitive style than males by selecting fewer cards from the disadvantageous decks [F(1, 49) = 14.218; P < 0.001] and showed an improvement throughout the task, as noted in a normal learning curve [F(1.49) = 4.385; P = 0.041)]. For the AGNG, an interaction specific to the negative valence stimuli on response bias measures was found. Abused females scored higher (mean = 8.38; SD = 6.39) than abused males (mean = 0.69; SD = 1.19) [F(1.46) = 6.348; P = 0.015].

Severity of childhood trauma was significantly different between sexes. In the context of a history of emotional abuse, male bipolar patients tended toward a more risk-taking behavior compared to female. Further investigations are needed to elucidate potential pathophysiological mechanisms underlying this interaction.