1. Investigación

Sex differences are poorly studied within the field of mental health, even though there is evidence of disparities (with respect to brain anatomy, activation patterns, and neurochemistry, etc.) that can significantly influence the etiology and course of mental disorders. The objective of this work was to review sex differences in adolescents (aged 13–18 years) diagnosed with ADHD (according to the DSM-IV, DSM-IV-TR and DSM-5 criteria) in terms of substance use disorder (SUD), prevalence, pharmacological therapy and mental health. We searched three academic databases (PubMed, Web of Science, and Scopus) and performed a narrative review of a total of 21 articles. The main conclusions of this research were (1) girls with ADHD are more at risk of substance use than boys, although there was no consensus on the prevalence of dual disorders; (2) girls are less frequently treated because of underdiagnosis and because they are more often inattentive and thereby show less disruptive behavior; (3) together with increased impairment in cognitive and executive functioning in girls, the aforementioned could be related to greater substance use and poorer functioning, especially in terms of more self-injurious behavior; and (4) early diagnosis and treatment of ADHD, especially in adolescent girls, is essential to prevent early substance use, the development of SUD, and suicidal behavior.

The technological revolution has led to the birth of new diagnoses, such as gaming disorder. When any addiction, including this one, is associated with other mental disorders, it is considered a dual diagnosis. The objectives of this current work were to estimate the prevalence of dual diagnoses in the adolescent general population while also considering the problematic use of video games and substance addiction and assessing its psychosocial risk factors. Thus, we carried out a cross-sectional study with a sample of 397 adolescents; 16.4% presented problematic videogame use and 3% presented a dual diagnosis. Male gender increased the probability of both a dual diagnosis (OR [95% CI] = 7.119 [1.132, 44.785]; p = 0.036) and problematic video game use (OR [95% CI] = 9.85 [4.08, 23.77]; p < 0.001). Regarding personality, low conscientiousness, openness, and agreeableness scores were predictors of a dual diagnosis and problematic videogame use, while emotional stability predicted a dual diagnosis (OR [95% CI] = 1.116 [1.030, 1.209]; p = 0.008). Regarding family dynamics, low affection and communication increased both the probability of a dual diagnosis (OR [95% CI] = 0.927 [0.891, 0.965]; p < 0.001) and problematic video game use (OR [95% CI] = 0.968 [0.945, 0.992]; p = 0.009). Regarding academic performance, bad school grades increased the probability of a dual diagnosis. In summary, male gender, certain personality traits, poor communication, and poor affective family dynamics should be interpreted as red flags that indicate an increased risk of a dual diagnosis in adolescents, which could require early intervention through specific detection programs.

Due to the significant functional repercussions suffered by patients with dual disorder, we must evaluate which ones can benefit from intensive rehabilitative therapies in medium-stay psychiatric units. This was a retrospective study of patient medical records which intended to analyze sociodemographic and clinical variables and parameters related to the hospitalization and discharge of patients admitted to the Medium-Stay Unit (MSU) at the Castellón Provincial Hospital Consortium over 2 years (2017 and 2018), according to the presence or absence of dual disorders in these patients. Patients with a dual disorder represented 55.2% of the hospitalized patients. A higher proportion of them were male, were relatively younger, and had an earlier onset of mental illness, fewer associated medical pathologies, and shorter hospital admission times to the Short-Term Hospitalization Unit than those who did not present a dual disorder. A diagnosis on the schizophrenia spectrum with cannabis use or polyconsumption was the most common diagnosis; 98.2% of all the patients responded adequately to admission to the MSU. This work highlighted the need for higher doses of depot paliperidone in patients with dual disorders.

Objective:Schizophrenia, cocaine-related disorder, antisocial personality disorder, andpsychopathy share biological bases, but few studies discriminate between these disordersby means of prepulse inhibition. This work studies the phenotype of patients with cocaine-related disorders who are vulnerable to presenting a dual diagnosis of schizophrenia orantisocial personality disorder, by evaluating their prepulse inhibition, impulsivity and psych-opathy personality traits.Methods:The sample (n¼38) was divided into three groups: (1)cocaine-related disorder (8 individuals diagnosed with cocaine-related disorder who did notpresent any other mental disorder), (2) cocaine-related disorder and schizophrenia (n¼14),and (3) cocaine-related disorder and antisocial personality disorder (n¼16).Results:Theprepulse inhibition in the two groups with dual diagnosis was lower than that in thecocaine-related disorder group,F(2, 35)¼6.52,p¼.004, while there was no significant differ-ences between the two dual-diagnosis groups. Psychopathy was evaluated with the revisedHare Psychopathy Checklist and showed no correlation with the prepulse inhibition.Secondary psychopathy (impulsivity and poor behavior control), as evaluated with LevensonSelf-Report Psychopathy Scale, was related to the prepulse inhibition. Two discriminating functions were obtained that allowed prediction of patient inclusion in the groups usingthe prepulse inhibition and the revised Hare Psychopathy Checklist with a success rate of81.6% (cocaine-related disorder¼62.5%; cocaine-related disorder and schizophrenia¼78.6%;cocaine-related disorder and antisocial personality disorder¼93.8%). These results are dis-cussed in regard to the neurobiological implications of prepulse inhibition in dual diagnosis.Conclusions:The results suggest that the prepulse inhibition is a promising dual-diagnosisvulnerability marker in individuals with cocaine addiction, because prepulse inhibition defi-cits are related both to schizophrenia and antisocial personality disorder. In addition, pre-pulse inhibition, which is considered a good endophenotype for studies on the genetic andneurobiological basis of cocaine-related disorder and schizophrenia, could be used in thesame way in studies on antisocial personality disorder.