Neurocognitive functioning in dually diagnosed middle aged and elderly patients with alcoholism and schizophrenia

Reaction Time and Visual Memory in Connection with Alcohol Use in Schizophrenia and Schizoaffective Disorder

The purpose of this study was to explore the association between cognition and hazardous drinking and alcohol use disorder in schizophrenia and schizoaffective disorder. Cognition is more or less compromised in schizophrenia, and schizoaffective disorder and alcohol use might aggravate this phenomenon. The study population included 3362 individuals from Finland with diagnoses of schizophrenia or schizoaffective disorder. Hazardous drinking was screened with the AUDIT-C (Alcohol Use Disorders Identification Test for Consumption) screening tool. Alcohol use disorder (AUD) diagnoses were obtained from national registrar data. Participants performed two computerized tasks from the Cambridge Automated Neuropsychological Test Battery (CANTAB) on a tablet computer: The Five-Choice Serial Reaction Time Task (5-CSRTT) or the reaction time (RT) test and the Paired Associative Learning (PAL) test. The association between alcohol use and the RT and PAL tests was analyzed with log-linear regression and logistic regression, respectively. After adjustment for age, education, housing status, and the age at which the respondents had their first psychotic episodes, hazardous drinking was associated with a lower median RT in females and less variable RT in males, while AUD was associated with a poorer PAL test performance in terms of the total errors adjusted scores (TEASs) in females. Our findings of positive associations between alcohol and cognition in schizophrenia and schizoaffective disorder are unique.

Executive Functioning in Men with Schizophrenia and Substance Use Disorders. Influence of Lifetime Suicide Attempts

Background

Lifetime suicide attempts in patients with comorbidity between psychotic disorders and Substance Use Disorder (SUD), known as dual diagnosis, was associated with a worse clinical and cognitive state, poor prognosis and premature death. However, to date no previous study has examined the cognitive performance of these patients considering as independent the presence or absence of lifetime suicide attempts.

Methods

We explore executive functioning differences between suicide attempters and non-attempters in dual schizophrenia (DS) patients and the possible related factors for both executive performance and current suicide risk. Fifty DS male patients in remission of SUD and clinically stables, 24 with and 26 without lifetime suicide attempts, were evaluated. We considered Z scores for all neuropsychological tests and a composite summary score for both premorbid IQ and executive functioning.

Results

DS patients showed low performance in set-shifting, planning and problem solving tasks. Those with suicide attempts presented lower composite summary scores, together with worse problem solving skills and decision-making, compared with non-attempters. However, after controlling for alcohol dependence, only differences in decision-making remained. Executive functioning was related to the premorbid intelligence quotient, and several clinical variables (duration, severity, months of abstinence and relapses of SUD, global functioning and negative symptoms). A relationship between current suicide risk, and first-degree relatives with SUD, insight and positive symptoms was also found.

Conclusions

Our results suggest that problem solving and, especially, decision-making tasks might be sensitive to cognitive impairment of DS patients related to presence of lifetime suicide attempts. The assessment of these executive functions and cognitive remediation therapy when necessary could be beneficial for the effectiveness of treatment in patients with DS. However, further research is needed to expand our findings and overcome some limitations of this study.

Neuropsychological Performance in Polyconsumer Men Under Treatment. Influence of Age of Onset of Substance Use

Neurocognition is a key factor in the development and maintenance of Substance Use Disorders (SUD). However, there are still several aspects that need to be studied in this area. In this study, we elucidate the influence of age of onset of substance use (OSU) on the clinical course and neuropsychological performance of substance use disorder (SUD) patients, as well as to explore the influence of years of education, duration of drug use and premorbid intelligence quotient (IQ) on the cognitive results obtained. An exhaustive neuropsychological battery was used to assess different cognitive domains in 80 male polyconsumers, 41 with earlier OSU (16 years or before: OSU ≤ 16) and 39 with later OSU (17 years or later: OSU ≥ 17). The patients were under treatment with at least 4 months of abstinence confirmed by urinalysis. The OSU ≤ 16 group presented a worse clinical state, as well as a lower premorbid IQ and worse performance in processing speed, visual perception and planning skills. The duration of drug use may account for the differences in planning and processing speed. In this work we discuss the premorbid or acquired nature of the cognitive deficits found.

Light alcohol intake during adolescence induces alcohol addiction in a neurodevelopmental model of schizophrenia

Schizophrenia is a mental disorder characterized by a series of positive, negative or cognitive symptoms but with also the particularity of exhibiting a high rate of co-morbid use of drugs of abuse. While more than 80% of schizophrenics are smokers, the second most consumed drug is alcohol, with dramatic consequences on frequency and intensity of psychotic episodes and on life expectancy. Here we investigated the impact of light alcohol intake during adolescence on the subsequent occurrence of alcohol addiction-like behavior in neonatal ventral hippocampal lesion (NVHL) rats, a neurodevelopmental model of schizophrenia. Our findings demonstrated an increased liability to addictive behaviors in adult NVHL rats after voluntary alcohol intake during adolescence. NVHL rats displayed several signs of alcohol use disorder such as a loss of control over alcohol intake and high motivation to consume alcohol, associated with a higher resistance to extinction. In addition, once NVHL rats relapsed, they maintained higher drinking levels than controls. We finally showed that the anti-addictive drug naltrexone is efficient in reducing excessive alcohol intake in NVHL rats. Our results are in accordance with epidemiological studies underlying the particular vulnerability to alcohol addiction after adolescent exposure to alcohol and highlight the fact that schizophrenic subjects may be particularly at risk even after light alcohol consumption. Based on these results, it seems particularly relevant to prevent early onset of alcohol use in at-risk subjects and thus to reduce the incidence of co-morbid alcohol abuse in psychotic patients.

Dual diagnosis in older adults: a review

Dual diagnosis is associated with frequent relapse, poor treatment engagement and overall unsatisfactory treatment outcomes. A comprehensive review of the contemporary literature examining this issue was conducted, finding a paucity of literature concerning dual diagnosis in older adults. Of the literature appraised for this review, a number of studies examined US Veteran's Affairs populations, which were largely male. Studies concerning older mental health populations were scarce. During the literature search, a number of background studies that influenced contemporary research regarding dual diagnosis in older adults were found; these studies were examined regarding their contribution to contemporary paradigms concerning older adults with co-occurring mental illness and substance use disorders. This review presents the results of the contemporary literature concerning dual diagnosis in older adults. Several recurring themes emerge from the literature, including the notion of a statistically small population that, in absolute terms, represents a sizeable number of individuals coming to the attention of aged mental health services in the future. Additionally, the potential for under-diagnosis in this cohort is highlighted, potentially creating a hidden population of older adults with dual diagnosis.

The impact of alcohol on clinical outcomes in established psychosis: a longitudinal study

BACKGROUND AND AIMS

Alcohol use disorders are common among people with psychosis and are associated with poorer prognoses. In psychosis patients, there are inconsistent findings regarding the link between alcohol disorders and clinical symptomatic outcomes. This study examined the relationships between alcohol consumption and specific clinical outcomes, including affective symptoms, in psychosis.

METHODS

Participants were recruited from secondary care services in the United Kingdom. Two hundred and ten participants whose substance use met inclusion for an alcohol disorder were compared with other substance users (n = 117) on baseline demographic, clinical and substance use variables. The alcohol subgroup was assessed at three time-points, with repeated measures of psychopathology and alcohol use over a 2-year period. Generalized estimating equations (GEE) models were used to examine whether change in alcohol use was associated with change in clinical outcomes. We controlled for a wide range of potential confounds, including other substance use.

RESULTS

A small but specific effect was evident for change in the quantity of alcohol consumed on change in depression (adjusted coefficient for 10 total units over 90 days: 0.0015, P = 0.047). Alcohol consumption was not associated with subsequent severity of psychotic symptoms (adjusted coefficient for Positive and Negative Syndrome Scale general for 10 average daily units 0.2492, P = 0.420) or severity of anxiety symptoms (adjusted coefficient for 10 average daily units 0.0534, P = 0.473).

CONCLUSIONS

For people with psychosis, the most detrimental effect of alcohol consumption appears to be its effect on mood. Some of this effect seems to be reversible, with drinking reduction associated with subsequent mood improvement.

Comorbid substance use disorder in schizophrenia: a selective overview of neurobiological and cognitive underpinnings

Although individuals with schizophrenia show a lifetime prevalence of 50% for suffering from a comorbid substance use disorder, substance abuse usually represents an exclusion criterion for studies on schizophrenia. This implies that surprisingly little is known about a large group of patients who are particularly difficult to treat. The aim of the present work is to provide a brief and non-exhaustive overview of the current knowledgebase about neurobiological and cognitive underpinnings for dual diagnosis schizophrenia patients. Studies published within the last 20 years were considered using computerized search engines. The focus was on nicotine, caffeine, alcohol, cannabis and cocaine being among the most common substances of abuse. All drugs of abuse target dopaminergic, glutamatergic and GABAergic transmission which are also involved in the pathophysiology of schizophrenia. Current literature suggests that neurocognitive function might beless disrupted in substance-abusing compared to non-abusing schizophrenia patients, but in particular the neuroimaging database on this topic is sparse. Detrimental effects on brain structure and function were shown for patients for whom alcohol is the main substance of abuse. It is as yet unclear whether this finding might be an artifact of age differences of patient subgroups with different substance abuse patterns. More research is warranted on the specific neurocognitive underpinnings of schizophrenia patients abusing distinct psychoactive substances. Treatment programs might either benefit from preserved cognitive function as a resource or specifically target cognitive impairment in different subgroups of addicted schizophrenia patients.

Neuropsychological functioning and age-related changes in schizophrenia and/or cocaine dependence

Although little is known about the combined effects of Schizophrenia (SZ) and Substance Use Dependence (SUD) in neurocognitive functioning, the current literature points out that performance depends on the specific cognitive domains, the age of individuals and the type of substance of abuse. Our aim is to elucidate, in a sample with SZ and/or cocaine dependent individuals in remission for more than 4 months, their performance in attention, verbal memory and speed of processing, taking into account the possible effect of both age and duration of SUD. The total sample consisted of 95 male patients, aged 20 to 60 years, divided in three groups: one group with SZ and cocaine dependence (SZ+), another group with SZ without cocaine dependence (SZ-) and a third group with cocaine dependence without psychiatric comorbidity (COC). Our results show that those SZ+ who were abstinent for more than four months did not differ from their SZ- counterparts in the neuropsychological functioning. Both SZ groups performed significantly worse than the COC group. A negative impact of age on the neuropsychological performance was found in the SZ+ group, suggesting additive later cognitive deficits in SZ+ patients due to the long-term brain damage of SUD.

Patterns of Axis I comorbidity in relation to age in patients with Bipolar Disorder: a cross-sectional analysis

BACKGROUND

Several data indicate that the clinical course and treatment response of Bipolar Disorder (BD) is influenced by comorbidity. However, whether differences in comorbidity patterns exist in relation to classes of age remains debated. The present study was aimed to evaluate differences in terms of cross-sectional Axis I comorbidity among young (≤30 years), adult (>30 and ≤45 years) and older adult patients with BD (>45 years).

METHODS

Study sample included 508 patients with BD, subdivided into 3 groups of age: ≤30 years (n=52), >30 and ≤45 years (n=186) and >45 years (n=270). Demographic and clinical variables, with specific emphasis on Axis I comorbidity, were compared across the different groups using chi-square tests. Furthermore, a binary logistic regression was performed.

RESULTS

Two-hundred eleven patients (41.5%) showed at least another concomitant Axis I disorder. The 3 groups were homogenous in terms of type of diagnosis (type 1 or 2 BD) and gender. However, they were different in terms of cross-sectional Axis I comorbidity (p=0.001) with a higher frequency of substance abuse (p=0.04) and Anorexia (p=0.014) in young patients, and of Obsessive Compulsive Disorder in adult patients (p=0.001). In addition, young patients showed more frequently the presence of a second comorbid Axis I condition compared to the other sub-groups (p=0.05). With regard to the type of abuse, young subjects were more frequently cannabis (p<0.001) and cocaine abusers (p<0.001) compared to the other subgroups.

LIMITATIONS

Lifetime Axis I and Axis II and cross-sectional Axis II comorbidity patterns were not analyzed.

CONCLUSIONS

Preliminary results from the present exploratory study seem to suggest different profiles of cross-sectional Axis I comorbidity and abuse in bipolar patients in relation to age. This aspect should be taken into account for the choice of pharmacological treatments and global management in clinical practice.

Substance use in adolescence and psychosis: clarifying the relationship

Adolescence is a time of exploration of the self, and this exploration may involve the use of alcohol and drugs. Sadly, for some, adolescence also marks the first signs of a psychosis. The temporal proximity between the onset of substance use and of psychosis has been the cause of much debate. Here we review the association of alcohol, cannabis, stimulants, and other drugs with psychosis, and we conclude that the use of cannabis and the amphetamines significantly contributes to the risk of psychosis.

Cognitive impairment in dual diagnosis inpatients with schizophrenia and alcohol use disorder

Cognitive impairment has been found independently among individuals with schizophrenia and individuals with alcohol use disorders. Less is known about the nature and severity of cognitive impairment in patients with a dual diagnosis, though the co-occurrence of these disorders may further exacerbate cognitive impairment. The study investigates the possible additive effect of alcohol use disorder and schizophrenia on cognitive impairment among patients diagnosed with schizophrenia. Participants were inpatients with schizophrenia (n=30), inpatients with a dual diagnosis of schizophrenia and alcohol use disorder (n=30), and matched controls (n=30): all completed a comprehensive neuropsychological battery. Both patient groups were significantly impaired, relative to controls, across the battery. Dual diagnosis patients were significantly more impaired than schizophrenia patients on delayed verbal memory, and executive functioning, primarily set-shifting, working memory, and planning, and had higher psychiatric morbidity scores. The findings provide support for an additive effect of the two disorders on cognitive impairment. These cognitive deficits may affect capacity to engage in treatment, increase risk of relapse, and adversely affect treatment outcomes. An understanding of the cognitive profile of people with dual diagnosis may help to tailor treatment delivery to meet their specific needs, enhance cognitive strengths, accommodate deficits and improve treatment outcomes.

Substance abuse is associated with increased extrapyramidal symptoms in schizophrenia: a meta-analysis

BACKGROUND

Psychoactive substances (PAS) may interact with antipsychotics in the development of extrapyramidal symptoms (EPS) in schizophrenia. PAS exert acute and chronic impacts on the basal ganglia. Clinical data have been gathered about the effects of PAS on EPS in schizophrenia, producing inconsistent results. This meta-analysis sought to determine whether PAS enhance EPS in schizophrenia patients.

METHODS

A search of the literature using computerized engines was undertaken. Studies were retained in the analysis if: (i) they included schizophrenia patients with and without substance abuse; and (ii) they comprised a measure of EPS using valid instruments.

RESULTS

Sixteen studies available were identified, involving 3479 patients. The composite analysis revealed a small and positive effect size (g=0.260), suggesting increased EPS in substance-abusing patients. Cocaine was associated with the largest effect size estimate (g=0.613). Dual diagnosis patients were more frequently males than single diagnosis patients. Thus, we performed a sub-analysis of studies with no confounders (e.g. age, sex and/or symptoms). The pooling of these 10 studies produced a moderate and positive effect size (g=0.401).

DISCUSSION

Our results show that PAS negatively impact on EPS in schizophrenia, especially when potential confounding factors are controlled. Cocaine emerged as the PAS with the most deleterious effects on EPS in schizophrenia. Our results have implications for the prevention of EPS in schizophrenia and for the design of future studies on the topic.

Comorbidity and temporal ordering of alcohol use disorders and other psychiatric disorders: results from a Danish register-based study

BACKGROUND

Understanding the comorbidity of alcohol use disorders (AUD) and other psychiatric disorders may have important implications for treatment and preventive interventions. However, information on the epidemiology of this comorbidity is lacking. The objective of this study was to present results on lifetime psychiatric comorbidity of AUD in a large Danish community population.

METHODS

A prospective cohort study was used, comprising 3 updated measures of sets of lifestyle covariates and 26 years of follow-up data on 18,146 individuals from the Copenhagen City Heart Study, Denmark. The study population was linked to national Danish hospital registers and a greater Copenhagen alcohol unit treatment register to detect registrations with AUD and other psychiatric disorders.

RESULTS

Of the individuals invited to the study, 7.6% were registered with AUD, and among these, 50.3% had a lifetime comorbid psychiatric disorder. Personality disorders were the most common comorbid disorders (24%) together with mood disorders (16.8%) and drug abuse (16.6%). The risk of developing a psychiatric disorder in individuals who were already registered with AUD was larger than the risk of developing AUD in individuals who were already registered with another psychiatric disorder; these differences in risk were especially noticeable for anxiety disorders, personality disorders, and drug abuse.

CONCLUSIONS

AUD is frequently comorbid with other psychiatric disorders, and it is likely that AUD is both an etiologic factor in other mental disorders and a consequence of mental disease. However, in interpreting these complex and perhaps circular causal links, it is important to consider that AUD is registered before a comorbid psychiatric diagnosis more often than the reverse temporal order.

Contradictory cognitive capacities among substance-abusing patients with schizophrenia: a meta-analysis

Although a substance use disorder (SUD) is traditionally associated with psycho-bio-social impairments, recent investigations among persons with schizophrenia (Sz) generated divergent results. Certain persons with Sz+SUD might in fact present better social and cognitive functioning than persons with Sz without SUD. This meta-analysis was conducted to verify this counterintuitive possibility and to determine whether factors such as substance type, severity or nature of psychotic symptoms and age of the patients help discriminate these subgroups. Twenty-three studies met the inclusion criteria and data from 1807 persons with schizophrenia, with or without comorbid SUD, were available for analyses. As a group, persons with Sz+SUD did not obtain significantly higher scores at a Global Cognitive Index than persons with Sz without SUD, although they were better at the Trail Making Task and the speed processing domain. Secondary analyses showed the importance of considering intermediate factors, particularly the preferred substance used and the mean age. While consumption of alcohol was associated with a global cognitive scores similar to that of persons with Sz without an SUD and lower working memory capacities, preferential use of cannabis was instead associated with higher scores for problem solving and reasoning and visual memory. Age was inversely related to the size of the effects. It is concluded that previous mixed results obtained with cognitive evaluations of persons with Sz+SUD might reflect the heterogeneity of participants and that subgroups of patients might be defined on the basis of intermediate factors.

The neuropsychology of cannabis and other substance use in schizophrenia: review of the literature and critical evaluation of methodological issues

Research on the neuropsychology of substance use in schizophrenia has been steadily growing over the past decade. However, significant gaps remain in the knowledge of individual substances and their relationship to cognition in the schizophrenia spectrum disorders. Approximately 65 studies to date have directly examined this relationship. Of these, approximately 20 have focused on nicotine, 15 on alcohol, 10 on cocaine, three on stimulants/hallucinogens, one on benzodiazepines, 10 on polydrug abuse, and seven on cannabis. Research on cannabis is especially lacking, given that worldwide it is the most commonly used illicit drug in schizophrenia, is used at higher rates in schizophrenia than in the general population, and makes its own unique contribution to the onset and prognosis of schizophrenia. In the present paper an overview of the neuropsychology literature on substance use in schizophrenia is presented, with special emphasis on cannabis. This incorporates a discussion of the methodological limitations inherent in these studies, and range of potential confounding variables that were not considered or controlled, providing directions for future research into the cognitive correlates of cannabis and other substance use in schizophrenia.

Meta-analysis of depressive symptoms in dual-diagnosis schizophrenia

Substance abuse is highly prevalent in schizophrenia and associated with numerous negative consequences. While studies have regularly reported more severe depressive symptoms in addicted schizophrenia patients relative to non-abusing patients, some studies have not corroborated this finding. The current meta-analysis was performed to quantify the relative severity of depressive symptoms in dual-diagnosis schizophrenia. A search of the literature using computerized engines was undertaken. Studies were retained in the analysis if (i) they assessed depressive symptoms using validated scales specific to depression (e.g. Hamilton Depression Rating Scale); and (ii) groups of schizophrenia patients were divided according to substance use disorders (alcohol, amphetamines, cannabis, cocaine, hallucinogens, heroin and/or phencyclidine). According to the inclusion criteria, 20 studies were available for mathematical analysis. A small, positive and significant effect size estimate (n =3283; 1680 dual diagnosis; 1603 single diagnosis; adjusted Hedges's g =0.292; p =0.003) was obtained, within a random-effect model, suggesting that some dual-diagnosis patients experience more severe depressive symptoms than single-diagnosis patients. This significant difference was found only for studies using the Hamilton Depression Rating Scale but not for other depression scales. The results of the present meta-analysis suggest that addicted schizophrenia patients experience more severe depressive symptoms compared to non-abusing patients, but that the difference is smaller than commonly assumed. The meta-analysis also shows that the significance of results is related to the scale used to measure depressive symptoms. These results have methodological implications for future studies of depressive symptoms in dual-diagnosis patients, and potential implications for the prevention and treatment of depressive symptoms in schizophrenia.