Predictive power of the ADHD GWAS 2019 polygenic risk scores in independent samples of bipolar patients with childhood ADHD.

BACKGROUND: Although there is evidence of genetic correlation between bipolar disorder (BP) and ADHD, the extent of the shared genetic risk and whether childhood ADHD (cADHD) influences the characteristics of the adult BP remain unclear. Our objectives were: (i) to test the ability of polygenic risk scores (PRS) derived from the latest PGC ADHD-GWAS (Demontis et al., 2019) to predict the presence of cADHD in BP patients; (ii) to examine the hypothesis that BP preceded by cADHD is a BP subtype with particular clinical traits and (iii) partially shares its molecular basis with ADHD. METHOD: PRS derived from the ADHD-GWAS-2019 were tested in BP patients (N = 942) assessed for cADHD with the Wender Utah Rating Scale and in controls from Romania and UK (N = 1616). RESULTS: The ADHD-PRS differentiated BP cases with cADHD from controls. Proband sex and BP age-of-onset significantly influenced the discriminative power of the ADHD-PRS. The ADHD-PRS predicted the cADHD score only in males and in BP cases with early age-of-onset (≤21 years). Bipolar patients with cADHD had a younger age-of-onset of mania/depression than patients without cADHD. The ADHD-PRS predicted the BP-affection status in the comparison of early-onset BP cases with controls suggesting a partial molecular overlap between early-onset BP and ADHD. LIMITATIONS: Retrospective diagnosis of cADHD, small sample size. CONCLUSIONS: The PRS-analysis indicated an acceptable predictive ability of the ADHD-SNP-set 2019 in independent BP samples. The best prediction of both cADHD and BP-affection status was found in the early-onset BP cases. The results may have impact on the individual disease monitoring.

Exome sequence analysis and follow up genotyping implicates rare ULK1 variants to be involved in susceptibility to schizophrenia.

Schizophrenia (SCZ) is a severe, highly heritable psychiatric disorder. Elucidation of the genetic architecture of the disorder will facilitate greater understanding of the altered underlying neurobiological mechanisms. The aim of this study was to identify likely aetiological variants in subjects affected with SCZ. Exome sequence data from a SCZ cas-control sample from Sweden was analysed for likely aetiological variants using a weighted burden test. Suggestive evidence implicated the UNC-51-like kinase (ULK1) gene, and it was observed that four rare variants that were more common in the Swedish SCZ cases were also more common in UK10K SCZ cases, as compared to obesity cases. These three missense variants and one intronic variant were genotyped in the University College London cohort of 1304 SCZ cases and 1348 ethnically matched controls. All four variants were more common in the SCZ cases than controls and combining them produced a result significant at P = 0.02. The results presented here demonstrate the importance of following up exome sequencing studies using additional datasets. The roles of ULK1 in autophagy and mTOR signalling strengthen the case that these pathways may be important in the pathophysiology of SCZ. The findings reported here await independent replication.

What Future Role Might N-Acetyl-Cysteine Have in the Treatment of Obsessive Compulsive and Grooming Disorders?: A Systematic Review.

Licensed pharmacological treatments for obsessive-compulsive disorders include selective serotonin reuptake inhibitors and tricyclic antidepressants. However, a large proportion of patients show minimal or no therapeutic response to these treatments. The glutamatergic system has been implicated in the etiology of obsessive-compulsive spectrum disorders, and it has been postulated that n-acetyl-cysteine (NAC) could have a therapeutic effect on these conditions through its actions on the glutamatergic system and the reduction of oxidative stress. A systematic review was conducted on the existing methodologically robust literature regarding the efficacy of NAC on obsessive-compulsive spectrum disorders in adults and children. Four randomized, double-blind placebo-controlled studies were identified, investigating the effects of NAC on obsessive-compulsive disorder, trichotillomania, and onychophagia. Results remain inconclusive, but NAC may still be useful as a treatment for obsessive-compulsive spectrum disorders on an individual level, particularly as the compound has a relatively benign side-effect profile. The dearth of methodologically robust work is clinically important: larger randomized controlled trials are required to inform of any meaningful clinical effectiveness, and to better determine which, if any, clinical populations might most benefit.

Dementia praecox redux: a systematic review of the nicotinic receptor as a target for cognitive symptoms of schizophrenia.

Most individuals with schizophrenia suffer some cognitive dysfunction: such deficits are predictive of longer-term functioning; and current dopamine-blocking antipsychotics have made little impact on this domain. There is a pressing need to develop novel pharmacological agents to tackle this insidious but most disabling of problems. The acetylcholinergic system is involved in cognitive and attentional processing, and its metabotropic and nicotinic receptors are widespread throughout the brain. Deficits in acetylcholinergic functioning occur in schizophrenia, and high rates of tobacco smoking have been posited to represent a form of self-medication. The nicotinic acetylcholine receptor (nAChR) has emerged as a putative target to improve cognitive deficits in schizophrenia, and this study systematically reviewed the emerging data. Nineteen studies were identified, covering three compound classes: agonists at the α7 and α 4ß2 nAChRs, and positive allosteric modulators. Overall data are underwhelming: some studies showed significant improvements in cognition but as many studies had negative findings. It remains unclear if this represents drug limitations or nascent study methodology problems. The literature is particularly hindered by variability in inclusion of smokers, generally small sample sizes, and a lack of consensus on cognitive test batteries. Future work should evaluate longer-term outcomes, and, particularly, the effects of concomitant cognitive training.

Taking the fuel out of the fire: evidence for the use of anti-inflammatory agents in the treatment of bipolar disorders.

BACKGROUND: Inflammation has emerged as a potentially important factor - and thus putative pharmacological target - in the pathology of bipolar disorders. However to date no systematic evaluations of the efficacy of add on anti-inflammatory treatment for the depressive and manic episodes have been carried out. METHODS: Sixteen articles were ultimately identified - by computer searches of databases (including PsycINFO, MEDLINE, and EMBASE), supplemented by hand searches and personal communication - as meeting study inclusion criteria. RESULTS: Anti-manic effects were evaluated in two trials, one of adjunctive n-acetyl cysteine (NAC), one of omega-3 fatty acids (O3FA), and significant improvements only emerged for NAC. Celecoxib had a rapid but short-lived antidepressant effect. Despite limited effects of O3FA on symptoms, imaging data demonstrated alterations in neuronal functioning that might have longer-term therapeutic effects. Evidence was strongest for adjunctive NAC in bipolar depression though conclusions are limited by small sample sizes. LIMITATIONS: Definitive conclusions are limited by the paucity of data, small study sizes, and the variability in methodology used. CONCLUSIONS: Current evidence for aspirin or celecoxib is insufficient though further investigation of the potential of celecoxib in early illness onset is warranted. Variable evidence exists for add-on O3FA though an indication of short-term treatment effects on membrane fluidity and neuronal activity suggest longer follow-up assessment is needed. The strongest evidence emerged for NAC in depression and future studies must address the role of illness duration and patients׳ baseline medications on outcomes. Careful consideration of lithium toxicity in the elderly and renal impaired is essential.

Does rare matter? Copy number variants at 16p11.2 and the risk of psychosis: a systematic review of literature and meta-analysis.

BACKGROUND: In the last 5 years an increasing number of studies have found that individuals who have micro-duplications at 16p11.2 may have an increased risk of mental disorders including psychotic syndromes. OBJECTIVE: Our main aim was to review all the evidence in the literature for the association between copy number variants (CNVs) at 16p11.2 and psychosis. METHODS: We have conducted a systematic review and a meta-analysis utilising the PRISMA statement criteria. We included all original studies (published in English) which presented data on CNVs at 16p11.2 in patients affected by schizophrenia, schizoaffective disorder or bipolar disorder. RESULTS: We retrieved 15 articles which fulfilled our inclusion criteria. Eleven articles were subsequently selected for a meta-analysis that showed a 10 fold increased risk of psychosis in patients with proximal 16p11.2 duplications. We conducted a second meta-analysis of those studies with low risk of overlap in order to obtain the largest possible sample with the lowest risk of repeated results: 5 studies were selected and we found an odds ratio (OR) of 14.4 (CI=5.2-39.8; p<0.001) for psychosis with proximal 16p11.2 duplications. The results were not significant for micro-deletions in the same region. Finally extracting only those studies that included patients with schizophrenia we found an OR=16.0 (CI=5.4-47.3: p<0.001) CONCLUSIONS: There is a fourteen fold-increased risk of psychosis and a sixteen fold increased risk of schizophrenia in individuals with micro-duplication at proximal 16p11.2.

Classical hallucinogens as antidepressants? A review of pharmacodynamics and putative clinical roles.

Hallucinogens have been part of spiritual practice for millennia, but controversy surrounding their mind-manifesting effects led to their proscription by the mid-20th century, largely without evidence of harm or toxicity and despite nascent data suggesting therapeutic utility in treating depressive illnesses. This review explores their pharmacodynamic actions and the current limited data on their clinic effectiveness. These drugs appear to exert their psychedelic effects through their agonist or partial agonist activity at the serotonergic 5-HT2A receptor, though they also have affinity for other metabotropic serotonin receptors. Hallucinogen binding affects a wide range of intracellular signalling pathways, the precise nature of which remains incompletely understood. They alter the serotonergic tone of brainstem raphe nuclei that project through the brain; they interact with receptors in the prefrontal cortex altering connectivity patterns and intracellular functioning; and they disrupt inhibitory control of sensory input via the thalamus to the cortex. The serotonergic system has long been implicated in anxiety and depressive disorders, and is a major target of most existing antidepressants. Classical hallucinogens alter the functioning of this system, but not in the same way current medications do: whilst there are identified receptors and neurotransmitter pathways through which hallucinogens could therein produce therapeutic effects, the neurobiology of this remains speculative at this time. There is currently an extremely limited but growing literature on hallucinogen safety and clinical application. The drugs appear well tolerated by healthy controls and clinical populations, and the rapid tolerance to repeated administration might reduce the possibility of dependency. Clinical trials reported over the past decade have generally shown positive therapeutic potential, but they are notably few in number. Legislative policy has had a freezing effect on evaluation of these compounds, a better understanding of which might improve our knowledge of the processes involved in consciousness, the neuropathology of depression, and potentially open up new pharmacological therapies.

Ketamine as the prototype glutamatergic antidepressant: pharmacodynamic actions, and a systematic review and meta-analysis of efficacy.

The burden of depressive disorders and the frequent inadequacy of their current pharmacological treatments are well established. The anaesthetic and hallucinogenic drug ketamine has provoked much interest over the past decade or so as an extremely rapidly acting antidepressant that does not modify 'classical' monoaminergic receptors. Current evidence has shown several ways through which it might exert therapeutic antidepressant actions: blockade of glutamatergic NMDA receptors and relative upregulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) subtypes may alter cortical connectivity patterns; through intracellular changes in protein expression, including the proteins mammalian target of rapamycin (mTOR) and brain-derived neurotrophic factor (BDNF); and alteration of intracellular signalling cascades. The clinical evidence demonstrates rapid improvements in mood and suicidal thinking in most participants, although study numbers have generally been small and many trials are unblinded and methodologically weak. There is a small body of work to suggest ketamine might also augment electroconvulsive therapy and potentially have a role as a surgical anaesthetic in depressed patients. A major problem is that the effects of ketamine appear temporary, disappearing after days to weeks (although longer benefits have been sustained in some), and attempts to circumvent this through pharmacological augmentation have been disappointing thus far. These exciting data are providing new insights into neurobiological models of depression, and potentially opening up a new class of antidepressants, but there are significant practical and ethical issues about any future mainstream clinical role it might have.

The use of antipsychotics in preschoolers: a veto or a sensible last option?

Recent reports have illustrated a dramatic rise in the use of antipsychotics in preschool children, medications originally designed and licensed for the treatment of adult psychotic disorders. Within this context, the current usage and the associated diagnoses are reviewed and compared with official guidelines and licensing for such use, highlighting a controversial challenge for clinicians. A review of the evidence base of the relative efficacy of such medications for a range of disorders is given. Associated safety and side effects are discussed, with compelling evidence for increased adverse events associated with use of antipsychotics in preschoolers, and neurodevelopmental hypotheses are used to guide predictions of long-term risk. An apparent gap in the literature and evidence base supporting such use and elucidating the risks and benefits leaves a challenge for clinicians and researchers and hinders the development of appropriate guidelines. Pragmatism in clinical practice, mindful of the limited evidence base that does exist and the propensity for harm, is necessary; far more research is required in this important area.

Drug attitude in adolescents: a key factor for a comprehensive assessment.

OBJECTIVE: Very few studies have evaluated the subjective experience (SE) in children and adolescents treated with antipsychotics. The present study aimed to evaluate the SE of antipsychotics in adolescents diagnosed with different psychiatric conditions and to identify explanatory variables of adolescents' SE and compliance with treatment. METHODS: The Drug Attitude Inventory (DAI) was used to evaluate SE in 67 adolescents in 2 different countries (Italy and United Kingdom). Compliance was measured using a Likert scale completed by both patients and parents. To evaluate other parameters correlated to the SE, the following scales were administered: Clinical Global Impression Scale, Children's Global Assessment Scale, Extrapyramidal Symptoms Rating Scale, Barnes Akathisia Rating Scale, and EuroQoL (for quality of life). Multiple and logistic regression analyses were applied. RESULTS: No significant difference in drug attitude was found between psychotic and nonpsychotic patients. Our results showed a highly significant association between DAI and compliance (Spearman index, 0.33; P = 0.005); for all other variables, DAI associated significantly only with quality of life (r = 0.25; P = 0.03). The multivariable analysis confirmed the presence of a strong association between compliance and DAI (P = <0.001). In our sample, drug attitude was the only variable found to be correlated with the compliance, whereas extrapyramidal adverse effects showed an only marginally significant association. CONCLUSIONS: Our observations provide confirmation, also in adolescents, that drug attitude is strongly correlated with treatment compliance and underline the need in clinical assessments to always consider the patient's viewpoint.

To sleep or not to sleep: a systematic review of the literature of pharmacological treatments of insomnia in children and adolescents with attention-deficit/hyperactivity disorder.

OBJECTIVE: This systematic review assessed current evidence on sleep medication for attention-deficit/hyperactivity disorder (ADHD) patients, to establish appropriate guidance for clinicians faced with prescribing such medications. METHODS: Five articles (based on four pharmacological compounds) out of a total 337 were identified as evidence to guide pharmacological treatment of ADHD-related sleep disorders. Data regarding participant characteristics, measures of ADHD diagnosis, measures of sleep, and outcome data were extracted. RESULTS: Zolpidem and L-theanine both displayed a poor response in reducing sleep latency and increasing total sleep time, however L-theanine did produce an increase in sleep efficiency. Zolpidem produced high levels of side effects, leading to the largest dropout rate of all five studies. Clonidine reduced insomnia; and melatonin also exhibited a positive response, with reduced sleep latency, higher total sleep time, and higher sleep efficiency. CONCLUSIONS: There is a relative paucity of evidence for the pharmacological treatment of ADHD-related sleep disorders; therefore, further research should be conducted to replicate these findings and obtain reliable results.

Beyond dopamine: glutamate as a target for future antipsychotics.

The dopamine hypothesis of schizophrenia remains the primary theoretical framework for the pharmacological treatment of the disorder. Despite various lines of evidence of dopaminergic abnormalities and reasonable efficacy of current antipsychotic medication, a significant proportion of patients show suboptimal treatment responses, poor tolerability, and a subsequent lack of treatment concordance. In recent decades, intriguing evidence for the critical involvement of other neurotransmitter systems in the pathophysiology of schizophrenia has emerged, most notably of dysfunctions within the glutamate pathways. Consequently, the glutamate synapse has arisen as a promising target for urgently needed novel antipsychotic compounds-particularly in regards to debilitating negative and cognitive symptoms poorly controlled by currently available drugs. In this paper, recent findings integrating glutamatergic and dopaminergic abnormalities in schizophrenia and their implications for novel pharmacological targets are discussed. An overview of compounds in various stages of development is given: drugs enhancing NMDA receptor function as well as metabotropic glutamate receptor (mGluR) agonist and positive allosteric modulators (PAMs) are emphasised. Together with other agents more indirectly affecting glutamatergic neurotransmission, their potential future role in the pharmacotherapy of schizophrenia is critically evaluated.

Bipolar depression: clinically missed, pharmacologically mismanaged.

Bipolar affective disorders are common and frequently debilitating mental illnesses. Diagnostic criteria mean they are defined by the presence of pathological mood elevation, but research shows greater disease burden is inflicted by depressive phases (bipolar depression) both in terms of duration and impact of symptoms. Despite this there is consistent evidence for the underdiagnosis of bipolar depression and its misdiagnosis as a unipolar disorder, with significant subsequent impact on medication management. There is currently less robust evidence for the appropriate pharmacological approach in such individuals than in unipolar depression, and fewer guidelines for clinicians. Despite this there is clear and growing evidence that 'treatment as usual' of depressive symptomatology is ineffective at best, harmful at worst, and that there is little role for the use of antidepressants. Both mood stabilizers and antipsychotics demonstrate efficacy, and whilst there are emerging data on intraclass differences, more research is needed, particularly concerning bipolar II disorder. Present treatment strategies are limited by insufficient large randomized control trials, an inadequate understanding of the neuropathology of bipolar illnesses and a lack of tailored medications. Better clinical training, understanding and recognition of this common condition are essential.