Evidence map›Paper›PMID 41920340›Full record

ArticlePsychopharmacology2026

Sex-specific effects of chronic caffeine on impulsive choice and serotonergic markers in an ADHD rat model.

Amanda S Almeida, Daniela M Marques, Brendha Caroline B Martins, Humberto Masschmann, Catiane B Alves, Marcus Vinicius S Lara, Lisiane O Porciuncula

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Article in Psychopharmacology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Amanda S AlmeidaDepartamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - anexo, Bairro Santana, Porto Alegre, 90610-264, RS, Brazil.
Daniela M MarquesDepartamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - anexo, Bairro Santana, Porto Alegre, 90610-264, RS, Brazil.
Brendha Caroline B MartinsDepartamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - anexo, Bairro Santana, Porto Alegre, 90610-264, RS, Brazil.
Humberto MasschmannDepartamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - anexo, Bairro Santana, Porto Alegre, 90610-264, RS, Brazil.
Catiane B AlvesDepartamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - anexo, Bairro Santana, Porto Alegre, 90610-264, RS, Brazil.
Marcus Vinicius S LaraDepartamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - anexo, Bairro Santana, Porto Alegre, 90610-264, RS, Brazil.
Lisiane O PorciunculaDepartamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - anexo, Bairro Santana, Porto Alegre, 90610-264, RS, Brazil. loporciuncula@gmail.com.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

rationaleCaffeine had been proposed as an adjuvant therapy for Attention Deficit and Hyperactivity Disorder (ADHD). Although caffeine can ameliorate some ADHD-related behaviors, its effects on impulsivity (more prevalent in boys) and potential sex differences, remains unclear.

objectivesTo assess sex differences in responsiveness to chronic caffeine on impulsive choice, brain cell composition and serotonergic markers in an ADHD rat model.

methodsMale and female Spontaneously Hypertensive Rats (SHR, ADHD model) and Wistar-Kyoto rats (WKY, control strain) received caffeine (0.3 g/L in drinking water) from postnatal day (PND) 15. Impulsive-like behavior was assessed with delayed discounting task (DDT) from PND 28-56. In frontal cortex and hippocampus, we quantified 5-HT2A and 5-HT1B serotonin receptors, the serotonin transport (SERT) and neuronal and non-neuronal nuclei.

resultsIn SHR of both sexes, caffeine reduced trials needed to reach criterion in the DDT. Effects on impulsive choice were sex dependent in SHR: caffeine increased choices of the large, delayed reward (reducing impulsive-like behavior) in males, but decreased such choices (promoting impulsive-like behavior) in females. In female SHR, caffeine increased the proportion of non-neuronal nuclei in frontal cortex and hippocampus. In the hippocampus of both sexes, caffeine lowered 5-HT2A receptor and SERT levels; females showed lower 5-HT2A than males. Effects in WKY were minimal.

conclusionsChronic caffeine exerts sex-specific behavioral and cellular effects in an ADHD model and modulates hippocampal serotonergic markers. These findings underscore the need to consider sex in caffeine-based adjunctive strategies for ADHD and motivate mechanistic studies to explain divergent responses.

Indexed as

AdenosineADHDImpulsivitySerotonin; caffeineSHR

Identifiers

PMID41920340

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.