This narrative review examines the effects of caffeine on brain health in older adults, with particular attention to its potential for dependence—an often-overlooked issue in geriatric care. Caffeine acts on central adenosine, dopamine, and glutamate systems, producing both stimulating and rewarding effects that can foster tolerance and habitual use. Age-related pharmacokinetic and pharmacodynamic changes prolong caffeine’s half-life and increase physiological sensitivity in the elderly. While moderate consumption may enhance alertness, attention, and possibly offer neuroprotective effects—especially in Parkinson’s disease and Lewy body dementia—excessive or prolonged use may lead to anxiety, sleep disturbances, and cognitive or motor impairment. Chronic exposure induces neuroadaptive changes, such as adenosine receptor down-regulation, resulting in tolerance and withdrawal symptoms, including headache, irritability, and fatigue. These symptoms, often mistaken for typical aging complaints, may reflect a substance use disorder yet remain under-recognized due to caffeine’s cultural acceptance. The review explores caffeine’s mixed role in neurological disorders, being beneficial in some and potentially harmful in others, such as restless legs syndrome and frontotemporal dementia. Given the variability in individual responses and the underestimated risk of dependence, personalized caffeine intake guidelines are warranted. Future research should focus on the long-term cognitive effects and the clinical significance of caffeine use disorder in older populations.

Hiccups are sudden, repeated, and involuntary contractions of the diaphragm muscle (myoclonic contraction). It involves a reflex arc that, once activated, causes a strong contraction of the diaphragm immediately followed by the closure of the glottis translating into the classic hic sound. Hiccups can be short, persistent, and intractable depending on the duration. The most disabling hiccups often represent the epiphenomenon of a medical condition such as gastrointestinal and cardiovascular disorders; central nervous system (CNS) abnormalities; ear, nose, and throat (ENT) conditions or pneumological problems; metabolic/endocrine disorders; infections; and psychogenic disorders. Some drugs, such as aripiprazole, a second-generation antipsychotic, can induce the onset of variable hiccups. We describe herein the cases of three hospitalized patients who developed insistent hiccups after taking aripiprazole and who positively responded to low doses of gabapentin. It is probable that aripiprazole, prescribed at a low dosage (7.5mg/day), would act as a dopamine agonist by stimulating D₂ and D₃ receptors at the hiccup center levellocated in the brain stemthus triggering the hiccup. On the other hand, gabapentin led to a complete regression of the hiccup probably by reducing the nerve impulse transmission and modulating the diaphragmatic activity. The present case series suggests the use of low doses of gabapentin as an effective treatment for aripiprazole-induced hiccups. However, our knowledge of the neurotransmitter functioning of the hiccup reflex arc is still limited, and further research is needed to characterize the neurotransmitters involved in hiccups for potential novel therapeutic targets.

The processing of the amyloid precursor protein (APP) is a critical event in the formation of amyloid plaques. Platelets contain most of the enzymatic machinery required for APP processing and correlates of intracerebral abnormalities have been demonstrated in platelets of patients with AD. The goal of the present paper was to analyze studies exploring platelet APP metabolism in Alzheimer’s disease patients trying to assess potential reliable peripheral biomarkers, to offer new therapeutic solutions and to understand the pathophysiology of the AD. According to the PRISMA guidelines, we performed a systematic review through the PubMed database up to June 2020 with the search terms: “((((((APP) OR Amyloid Precursor Protein) OR AbetaPP) OR Beta Amyloid) OR Amyloid Beta) OR APP-processing) AND platelet”. Thirty-two studies were included in this systematic review. The papers included are analytic observational studies, namely twenty-nine cross sectional studies and three longitudinal studies, specifically prospective cohort study. The studies converge in an almost unitary way in affirming that subjects with AD show changes in APP processing compared to healthy age-matched controls. However, the problem of the specificity and sensitivity of these biomarkers is still at issue and would deserve to be deepened in future studies.

Background: Chronic cocaine exposure is increasingly associated with persistent brain alterations, yet it remains unclear whether these changes reflect reversible neuroadaptation, accelerated brain ageing, or a degeneration-like trajectory in a vulnerable subgroup. This Perspective proposes a neuroprogressive vulnerability framework—referred to as cocaine-specific encephalopathy/cerebropathy only in a heuristic sense—to organise heterogeneous evidence without implying a distinct neurodegenerative disease entity. Methods: We conducted a structured, critical synthesis of peer-reviewed human and preclinical literature (PubMed, Scopus, Web of Science; inception to December 2025), integrating neuroimaging (MRI/DTI/fMRI/PET/SPECT), neuropathology/post-mortem findings, neurochemical and molecular mechanisms, and neuropsychological outcomes, with explicit attention to confounders (polysubstance use, psychiatric and medical comorbidity, HIV, vascular risk, abstinence duration). Results: Convergent evidence supports a multi-hit vulnerability model in which chronic stimulant exposure may weaken neural resilience through dopaminergic dysregulation, oxidative stress, mitochondrial dysfunction, neuroinflammatory signalling, and putative α-synuclein–related mechanisms. Human imaging studies consistently implicate fronto–striato–limbic circuits and suggest possible cerebellar involvement, but findings are heterogeneous and often cross-sectional; direct evidence of progressive neuronal loss or disease-defining proteinopathies attributable to cocaine remains limited. Conclusions: Rather than asserting cocaine-induced classic neurodegeneration, we outline an exploratory framework in which chronic cocaine exposure may increase susceptibility to neuroprogressive impairment in a subset of biologically vulnerable individuals. Longitudinal multimodal studies combining advanced imaging, biomarkers, and phenotypic stratification are needed to clarify causality, temporal progression, and reversibility with sustained abstinence.

Background: Attention-Deficit/Hyperactivity Disorder (ADHD) in adulthood is frequently associated with complex psychiatric comorbidity, including high rates of Substance Use Disorders (SUDs), which may influence treatment outcomes. Although pharmacological treatments are effective for core ADHD symptoms, real-world response remains heterogeneous, and the contribution of specific substance-related and neurodevelopmental factors to treatment response is not fully understood. Methods: This retrospective observational study examined a real-world cohort of 67 adults with ADHD treated pharmacologically in a specialized outpatient setting. ADHD was diagnosed according to DSM-5-TR criteria using the Diagnostic Interview for ADHD in Adults (DIVA-5). Autism spectrum disorder (ASD) was recorded based on documented pre-existing specialist diagnoses and confirmed clinically at baseline. Psychiatric comorbidities and substance use disorders, including alcohol and cannabis use disorders, were assessed according to DSM-5-TR criteria. Clinical response was defined using the Clinical Global Impression–Improvement scale (CGI-I; responders = scores 1–3). Exploratory binary logistic regression analyses were used to identify clinical factors associated with treatment response. Given the limited sample size, revised multivariable models were specified parsimoniously on the basis of a priori clinical relevance. Results: At follow-up, 48 of 67 patients (71.6%) met criteria for clinical response. In revised parsimonious multivariable models, alcohol use disorder (OR ≈ 0.08–0.10, p = 0.010–0.026) and cannabis use disorder (OR ≈ 0.20–0.24, p = 0.014–0.028) were consistently associated with reduced odds of clinical response. Autism spectrum disorder showed a descriptive trend toward lower response rates but did not retain statistical significance after adjustment (p ≈ 0.11–0.15). Conclusions: In adults with ADHD treated in routine clinical practice, alcohol and cannabis use disorders were associated with a reduced likelihood of achieving clinically meaningful improvement under routine pharmacological care, whereas autism spectrum disorder showed a trend toward lower response that was not stable enough to support firm conclusions. These findings should be considered exploratory given the retrospective design, limited sample size, and lack of systematic treatment exposure measures.