Childhood serotonergic function and early adult outcomes in youth with ADHD: A 15-year follow-up study

Systematic Review and Meta-Analysis: Predictors of Adult Psychiatric Outcomes of Childhood Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Psychiatric disorders are highly prevalent in adults with childhood-onset attention-deficit/hyperactivity disorder (ADHD). Currently, little is known about childhood predictors for these outcomes.

METHOD

PubMed, PsychInfo, WoS, and EMBASE were searched until June 2024. Eligible studies investigated childhood predictors of persistent ADHD, substance use disorders (SUD), conduct disorder, antisocial personality disorder, major depressive disorder (MDD), and/or anxiety disorders in adults diagnosed with childhood ADHD (PROSPERO #CRD42022320887). Meta-analytic models were tested when N ≥3 for a predictor with similar effect measures, otherwise predictors were discussed narratively when N ≥2. Newcastle-Ottawa scale was used to assess study quality.

RESULTS

The selected 36 studies included 119 predictors, with 10 predictors eligible for meta-analyses. History of stimulant treatment (OR = 1.88, 95% CI 1.28-2.75, p = .001) was associated with increased, and higher childhood IQ with decreased (OR = 0.99, 95% CI 0.98-1.00, p =.039), risk of ADHD persistence in adulthood. ADHD persistence was associated with increased risk of SUDs (OR = 2.12, 95% CI 1.53-3.17, p =.004) and MDD (OR = 3.19, 95% CI 1.71-5.95, p <.001). Narratively reviewed predictors of fair/good quality studies showed potential predictors for ADHD persistence (i.e., ADHD combined type, hyperactive/impulsive symptoms, anxiety disorders, externalizing problems, social dysfunctioning, and socioeconomic status).

CONCLUSION

We confirmed earlier reported childhood predictors (i.e., stimulant treatment history, ADHD persistence) and identified potential new predictors (i.e., childhood anxiety disorders, social problems, socioeconomic status) for psychiatric outcomes of ADHD. However, the available literature is hampered by methodological shortcomings. Future studies should focus on studying combined effects of potential predictors.

Prolactin levels increased by physical exercise correlate with platelet monoamine oxidase activity: Evidence linking platelet MAO with serotonin release capacity

OBJECTIVE

Lower platelet monoamine oxidase (MAO) activity has consistently been associated with excessive risk-taking and general psychiatric vulnerability. How this peripheral measure can represent presumably centrally regulated complex behaviours is not clear but platelet MAO activity has been suggested to reflect the capacity of serotonin release in the brain. Secretion of prolactin is in part under serotonergic control and indicates serotonin release capacity.

METHODS

We have assessed release of prolactin and other exercise-induced hormones in response to strenuous physical exercise in twenty male subjects and examined its association with platelet MAO activity as measured radioenzymatically.

RESULTS

Increase in prolactin levels was positively correlated with platelet MAO activity. Levels of cortisol, growth hormone and aldosterone were also raised by exercise, but these increases were not associated with platelet MAO activity. Unexpectedly, aldosterone levels before exercise were also in a positive correlation with platelet MAO activity.

CONCLUSION

The finding that exercise-induced prolactin release is associated with MAO activity in platelets indirectly supports the notion that platelet MAO activity is a marker of central serotonin release capacity.

Attention Deficit Hyperactivity Disorder (ADHD) Causes and Diagnosis in Adults: A Review

This article focuses on attention deficit hyperactivity disorder (ADHD) in males of the adult age group, exploring its causes and diagnosis. ADHD is commonly identified in children and teenagers, often leading to academic difficulties. Diagnosing adult ADHD involves evaluating recent symptoms, assessing childhood history, examining functional impairment, obtaining developmental and mental health backgrounds, and ruling out other psychiatric conditions. The diagnostic assessment primarily relies on patient interviews, though input from family members and other sources can be valuable. Men and women show differences in ADHD symptoms and associated neurological conditions, with males more frequently diagnosed with ADHD. Inattention, hyperactivity, and impulsivity are signs of ADHD. The difficulties in identifying adult ADHD and separating it from behavioural problems are covered in the essay. It also explores the various symptoms of ADHD in children and adults and their impact on daily life. The causes of ADHD involve abnormalities in brain structure and function, as well as genetic factors. Treatment options for adult ADHD encompass medication, education, skill training, and psychological counselling. While medications can help manage symptoms, they do not provide a cure. The article concludes by emphasizing the need for a healthy lifestyle alongside therapy and medication to manage ADHD symptoms effectively.

Delay discounting and neurocognitive correlates among inner city adolescents with and without family history of substance use disorder

Adolescents with a family history (FH+) of substance use disorder (SUD) are at a greater risk for SUD, suggested to be partly due to the transmission of behavioral impulsivity. We used a delay discounting task to compare impulsivity in decision-making and its associated brain functioning among FH+ and FH - minority adolescents. Participants chose between Smaller Sooner (SS) and Larger Later (LL) rewards. The SS was available immediately (Now trials) or in the future (Not-Now trials), allowing for greater differentiation between impulsive decisions. The FH+ group showed greater impatience by responding SS more frequently than the FH - group, only on the Now trials, and even when the relative reward differences (RRD) increased. Surprisingly, there were no differences in brain activity between the groups. Combined, the groups showed greater reward activity during the Now vs. Not-Now trials in medial prefrontal/anterior cingulate, posterior cingulate, precuneus, and inferior frontal gyrus (i.e., an immediacy effect). As the RRD increased activation in the reward network decreased, including the striatum, possibly reflecting easy decision-making. These results indicate that risk for SUD, seen behaviorally among FH+ adolescents, may not yet be associated with discernable brain changes, suggesting that early intervention has the potential to reduce this risk.