Each month our editorial team sifts through hundreds of papers and curates notable findings—for practitioners and informed readers who want to stay current with the evidence. Subscribe to the monthly Research Digest for expert analysis and concise summaries of key papers.
The authors combined results from 42 studies of people in prison to estimate how common ADHD is in those groups. Using formal diagnostic interviews, the overall ADHD rate was about 25.5%. Reported rates were higher when studies used screening tools or when adults recalled childhood ADHD. The review found much…
This paper reviews genetic studies that link several genes to higher risk for ADHD. It says problems in the brain's reward system—especially low dopamine activity—may make people seek things that raise dopamine. The authors propose that these gene variants form a “reward deficiency syndrome” (RDS) that may include ADHD, and…
Researchers reviewed records from 1,130 people with bipolar disorder seen at a mood-disorders center. They found that depressive episodes lasted much longer than manic episodes, and that episode length was similar across bipolar subtypes (BD-I, BD-II, mixed, or with psychosis). The authors say this pattern — more and longer depressions…
This small pilot randomized placebo‑controlled trial tested a cannabinoid spray (Sativex) in 30 adults with ADHD. The main test of cognition and activity (QbTest) showed no significant difference between Sativex and placebo in the intention‑to‑treat analysis (Estimate = -0.17, 95% CI -0.40 to 0.07, p = 0.16). Some secondary measures…
Most of the included studies were at high risk of bias and the overall quality of the evidence ranged from low to very low on most outcomes. Although amphetamines seem efficacious at reducing the core symptoms of ADHD in the short term, they were associated with a number of adverse…
Attention-deficit/hyperactivity disorder (ADHD) is a prevalent and serious neurodevelopmental disorder characterized by symptoms of inattention and/or hyperactivity/impulsivity. Chronic and childhood stress is involved in ADHD development, and ADHD is highly comorbid with anxiety. Similarly, inflammatory diseases and a pro-inflammatory state have been associated with ADHD. However, while several works have…
This 2017 clinical review explains how bipolar I and II disorders are diagnosed and treated. It says bipolar illness involves swings between manic (or hypomanic) and depressive episodes. Treatment usually needs both medicines and psychosocial therapy, and care must be adjusted over time because relapses and incomplete responses — especially…
The researchers surveyed 1,738 students about ADHD, cannabis use, and thinking skills. People with ADHD who had used cannabis said it gave them short-term benefits for many ADHD symptoms (for example, hyperactivity and impulsivity) and eased many medication side effects (for example, irritability and anxiety). The study also found that…
Long-term MRI studies show that people with bipolar disorder often have unusual brain changes over time, but the pattern is mixed and not fully clear. Some studies link manic episodes to faster thinning and volume loss in parts of the prefrontal cortex. A large multi-site study (307 patients, 925 controls,…
This systematic review looked at studies up to November 2023 on cannabis use and mood disorders. The authors included 78 studies and found that cannabis use was generally linked with more depressive and manic symptoms, a higher chance of developing major depressive disorder (MDD) and bipolar disorder (BD), and a…
This paper reviewed 12 factor-analysis studies of mania that together included 3,039 adult patients assessed by clinicians. The authors found that mania has several dimensions rather than a single core symptom. Hyperactivity, increased speech, and thought disorder tended to be the clearest core features. Mood symptoms (elevated or irritable mood)…
This systematic review looked for events that can trigger sudden mood episodes in people with bipolar disorder. The authors examined 108 studies published up to May 23, 2022. They found the strongest evidence that antidepressant use is linked to manic or hypomanic episodes. Other reported triggers for mania included brain…
