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Although Parkinson’s disease (PD) is most associated with and diagnosed by the presence of motor symptoms, non-motor symptoms (NMS) can often be the most debilitating for patients. Highly prevalent among non-motor features are neuropsychiatric symptoms (NPS), including depression, anxiety, psychosis, impulse control disorders, apathy and cognitive impairment, the latter being particularly burdensome and occurring in the majority of PD patients long term. The neurobiological underpinnings of NPS are a mix of disease-related, other neurodegenerative disease processes, PD treatment effects and psychosocial factors. NPS can be difficult to recognize and diagnose in PD patients; therefore, PD-specific assessments have been developed to better identify and treat them. Treatment strategies are a mix of those used in the general population for these conditions and those specific to PD, and are a combination of pharmacologic and non-pharmacologic interventions. Although significant advances have been made in our understanding and management of NPS in PD, etiology or biologically informed management strategies are needed to further advance the field.
Psychotic disorders are syndromes characterized by the presence of psychosis. The term psychosis denotes an abnormal mental status characterized by various forms of bizarre, disorganized behavior, disorganized or illogical thinking, misperception, and distortion of reality. Specific terms used to describe psychotic mental states include delusions and hallucinations. Psychosis as a phenomenon is not specific, nor is it pathognomonic for any single diagnosis, health condition, or particular etiology. As psychotic symptoms can result from numerous medical, neurological, and psychiatric illnesses, the presence of psychosis should prompt a search for the underlying etiology. Psychosis is considered “primary” when there is no identifiable inducing agent or medical condition. On the contrary, psychosis is considered “secondary” when the psychotic symptoms are induced by an identified medical or neurological condition, prescribed medications, drugs of abuse, exposure to toxins, or other causes. This chapter focuses on primary psychotic disorders including brief psychotic disorder, schizophreniform disorder, schizophrenia, schizoaffective disorder, and delusional disorder. The diagnostic criteria, epidemiology, genetics, neurobiology, clinical manifestations, and treatment of each psychotic disorder are described. However, more space will be dedicated to schizophrenia, as it is the prototypical psychotic disorder.
Psychiatric disorders are complex and multifaceted conditions that profoundly impact various aspects of an individual’s life. Although the neurobiology of these disorders is not fully understood, extensive research suggests intricate interactions between genetic factors, changes in brain structure, disruptions in neurotransmitter pathways, as well as environmental influence.
In the case of psychotic disorders, such as schizophrenia, strong genetic components have been identified as a key feature in the development of psychosis. Moreover, alterations in dopamine function and structural brain changes that result in volume loss seem to be pervasive in people affected by these disorders. Meanwhile, mood disorders, including major depressive disorder and bipolar disorder, are characterized by disruptions in neurotransmitter systems responsible for mood regulation, such as serotonin, norepinephrine, and dopamine. Anxiety and personality disorders also exhibit neurotransmitter dysfunction and neuroanatomical changes, in addition to showing a genetic overlap with mood and psychotic disorders.
Understanding the underlying mechanisms in the pathophysiology of these conditions is of paramount importance and involves integrating findings from various research areas, including at the molecular and cellular levels. This brief overview aims to highlight some of the important developments in our current understanding of psychiatric disorders. Future research should aim to incorporate a comprehensive approach to further unravel the complexity of these disorders and pave the way for targeted therapeutic strategies and effective treatments to improve the lives of individuals afflicted by them.
In this chapter, we discuss late-life psychiatric disorders highlighting their unique biological, clinical, and therapeutic features compared to presentations earlier in life. They are frequently overlapping and associated with dementia and other neurodegenerative diseases. The three D’s – delirium, dementia, and depression – represent common geriatric psychiatry syndromes that can pose diagnostic and therapeutic challenges. Clinical suspicion of delirium must prompt careful investigation of the underlying cause. Dementia is an umbrella term that describes progressive cognitive decline and related behavioral and functional impairments. Behavioral symptoms of dementia are a frequent reason for psychiatry referral. They have a more irregular course than the cognitive decline, and can be categorized in distinct dimensions. Late-life depression has unique features, such as the focus on somatic complaints instead of mood changes.
As part of the formative work of the SUCCEED Africa consortium, we followed a participatory process to identify existing gaps and resources needed for the development and implementation of a rights-based intervention for people with lived experience of psychosis in Malawi, Nigeria, Sierra Leone and Zimbabwe.
In 2021, we conducted a desk review of published and grey literature on psychosis in the four SUCCEED countries. Using an adapted version of the PRIME situation analysis template, data were extracted across the five domains of the WHO Community-Based Rehabilitation (CBR) Matrix: health, education, livelihoods, social and empowerment. This was supplemented with insights from personal communications with key stakeholders and the lived and professional experiences of team members.
Findings indicate that people with lived experience of psychosis have limited access to services and opportunities across the five CBR domains. Participation in social, religious, empowerment and political activities is restricted due to stigma and a lack of advocacy.
People with lived experience of psychosis in SUCCEED countries are not generally able to access support in line with essential components of CBR. There is a need for their greater inclusion in policy and advocacy activities.
Working memory deficit, a key feature of schizophrenia, is a heritable trait shared with unaffected siblings. It can be attributed to dysregulation in transitions from one brain state to another.
Aims
Using network control theory, we evaluate if defective brain state transitions underlie working memory deficits in schizophrenia.
Method
We examined average and modal controllability of the brain's functional connectome in 161 patients with schizophrenia, 37 unaffected siblings and 96 healthy controls during a two-back task. We use one-way analysis of variance to detect the regions with group differences, and correlated aberrant controllability to task performance and clinical characteristics. Regions affected in both unaffected siblings and patients were selected for gene and functional annotation analysis.
Results
Both average and modal controllability during the two-back task are reduced in patients compared to healthy controls and siblings, indicating a disruption in both proximal and distal state transitions. Among patients, reduced average controllability was prominent in auditory, visual and sensorimotor networks. Reduced modal controllability was prominent in default mode, frontoparietal and salience networks. Lower modal controllability in the affected networks correlated with worse task performance and higher antipsychotic dose in schizophrenia (uncorrected). Both siblings and patients had reduced average controllability in the paracentral lobule and Rolandic operculum. Subsequent out-of-sample gene analysis revealed that these two regions had preferential expression of genes relevant to bioenergetic pathways (calmodulin binding and insulin secretion).
Conclusions
Aberrant control of brain state transitions during task execution marks working memory deficits in patients and their siblings.
Psychotic-like experiences (PLEs) are subclinical phenomena that often precede the onset of psychosis and occur in various mental disorders. Social determinants of psychosis and PLEs are important and have been operationalized within the social defeat (SD) hypothesis. The SD hypothesis posits that low social status and exposure to repeated humiliation can lead to imbalanced dopamine neuron activity, and thus increased risk of psychosis. We aimed to assess the role of dynamic interactions between SD components in shaping the occurrence of PLEs using a network analysis.
Methods
A total of 2241 non-clinical, young adults were assessed at baseline and invited for reassessment after a 6-month follow-up. Self-reports recording the occurrence of PLEs, aberrant salience (AS), depressive, and anxiety symptoms as well as SD characteristics (socioeconomic status, minority status, humiliation, perceived constraints, and domain control) were administered. Two networks were analyzed (the first one covering all baseline measures and the second one with the baseline SD components and follow-up measures of AS and psychopathology).
Results
The SD components were not directly connected to the measures of PLEs in both networks. However, in both networks, SD components were connected to PLEs through a mediating effect of AS. Among SD components, humiliation had the highest bridge centrality across three predefined communities of variables (SD; depressive and anxiety symptoms; AS, and PLEs).
Conclusions
The findings indicate that SD might make individuals vulnerable to develop PLEs through the mediating effects of AS. Among SD components, humiliation might play the most important role in the development of PLEs.
Low- and middle-income countries (LMICs) bear a disproportionate burden of mental illness, with limited access to biomedical care. This study examined pathways to care for psychosis in rural Uganda, exploring factors influencing treatment choices.
Methods
We conducted a mixed-methods study in Buyende District, Uganda, involving 67 in-depth interviews and 4 focus group discussions (data collection continued until thematic saturation was reached) with individuals with psychotic disorders, family members, and local leaders. Structured questionnaires were administered to 41 individuals with psychotic disorders.
Results
Three main themes emerged: (1) Positive attitudes towards biomedical providers, (2) Barriers to accessing biomedical care (3) Perceived etiologies of mental illness that influenced care-seeking behaviors. While 81% of participants eventually accessed biomedical care, the median time to first biomedical contact was 52 days, compared to 7 days for any care modality.
Conclusions
Despite a preference for biomedical care, structural barriers and diverse illness perceptions led many to seek pluralistic care pathways. Enhancing access to biomedical services and integrating traditional and faith healers could improve mental health outcomes in rural Uganda.
Stigma of mental health conditions hinders recovery and well-being. The Honest, Open, Proud (HOP) program shows promise in reducing stigma but there is uncertainty about the feasibility of a randomized trial to evaluate a peer-delivered, individual adaptation of HOP for psychosis (Let's Talk).
Methods
A multi-site, Prospective Randomized Open Blinded Evaluation (PROBE) design, feasibility randomised controlled trial (RCT) comparing the peer-delivered intervention (Let's Talk) to treatment as usual (TAU). Follow-up was 2.5 and 6 months. Randomization was via a web-based system, with permuted blocks of random size. Up to 10 sessions of the intervention over 10 weeks were offered. The primary outcome was feasibility data (recruitment, retention, intervention attendance). Primary outcomes were analyzed by intention to treat. Safety outcomes were reported by as treated status. The study was prospectively registered: https://doi.org/10.1186/ISRCTN17197043.
Results
149 patients were referred to the study and 70 were recruited. 35 were randomly assigned to intervention + TAU and 35 to TAU. Recruitment was 93% of the target sample size. Retention rate was high (81% at 2.5 months primary endpoint), and intervention attendance rate was high (83%). 21% of 33 patients in Let's talk + TAU had an adverse event and 16% of 37 patients in TAU. One serious adverse event (pre-randomization) was partially related and expected.
Conclusions
This is the first trial to show that it is feasible and safe to conduct a RCT of HOP adapted for people with psychosis and individual delivery. An adequately powered trial is required to provide robust evidence.
Cognitive behavioural therapy (CBT) is one of the best-evidenced psychosocial interventions for psychosis and is recommended by the National Institute for Health and Care Excellence and the American Psychiatric Association. CBT was developed and derived from Western cultural values, which may not be appropriate for non-Western cultures. Trials of CBT in Western countries have indicated that participants from ethnic minority groups demonstrate low rates of engagement, retention, and recruitment. This indicates that the principles underlying CBT may conflict with individual beliefs and cultural values in non-Western countries. Therefore, we interviewed 15 people diagnosed with schizophrenia and 15 with their family members to explore the beliefs and attitudes of people diagnosed with schizophrenia and their family members concerning the proposed CBT intervention for psychosis in the Saudi context. The findings revealed that most participants accepted the proposed intervention. Important factors that influenced participants’ engagement and motivation in the CBT intervention were related to the therapist’s qualities (sex, empathy, and competence), family involvement, religion, and the number and format of CBT sessions for psychosis.
Key learning aims
(1) To explore the beliefs and attitudes of people diagnosed with schizophrenia concerning the proposed CBT intervention for psychosis and how to improve it to make it more appropriate for their needs and cultures.
(2) To explore the beliefs and attitudes of family members of people diagnosed with schizophrenia concerning the proposed CBT intervention for psychosis and how to improve it to make it more appropriate to their needs and culture.
Clinical characteristics of psychosis in HIV infection have been described, but there have been limited comparative studies in HIV-endemic low-resource regions.
Aim
To compare clinical characteristics of psychosis in HIV-positive and HIV-negative patients at the main psychiatric referral units in Uganda.
Method
Patients with psychosis were consecutively recruited and completed a standardised demographic questionnaire and psychiatric and laboratory assessments including an HIV test. The Mini International Neuropsychiatric Interview was used to diagnose psychiatric illness. Psychosis symptoms were compared between HIV-positive and HIV-negative individuals using bivariate methods. A logistic regression model was used to assess the effects of age, gender and HIV status on different types of psychosis.
Results
There were 478 patients enrolled, of which 156 were HIV positive and 322 were HIV negative. The mean age was 33.2 years (95% CI 31.8–34.5) for the HIV-positive group and 29.6 years (95% CI 28.7–30.5) for the HIV-negative group (P < 0.001). Female patients had a higher proportion of seropositivity 40.6% (95% CI 34.8–46.4) compared with males 21.8% (95% CI 16.1–27.5) (P < 0.001). Psychotic disorder not otherwise specified occurred more in the HIV-positive individuals (88% (95% CI 82.9–93.1) v. 12% (95% CI 8.4–15.5), P < 0.001). Motor activity, irritability, emotional withdrawal, feelings of guilt, mannerisms and posturing, grandiosity, suspiciousness, unusual thoughts, blunted affect, excitement and disorientation were associated with HIV seropositivity.
Conclusion
The presentation of psychosis in patients with HIV is unique to this HIV endemic setting. Characterisation of the symptomatology of patients presenting with psychosis is important for proper diagnosis and care.
Schizophrenia impacts several cognitive systems including language. Linguistic symptoms of schizophrenia are important to understand due to the crucial role that language plays in the diagnostic and treatment process. However, the literature is heavily based on monolingual-centric research. Multilinguals demonstrate differences from monolinguals in language cognition. When someone with schizophrenia is multilingual, how do these differences interact with their symptoms? To address this question, we conducted a pre-registered PRISMA-SR scoping review to determine themes in the literature and identify gaps for future research. Four hundred and twenty records were identified from three databases in 2023. Thirty articles were included in the synthesis. We found three emergent themes: (1) the need for multilingual treatment options, (2) differences in symptomology between the L1 and L2, and (3) the impact of cultural factors on linguistic functioning. Thus, several avenues of research regarding multilingualism may be fruitful for improving linguistic and social outcomes in schizophrenia.
Cannabis use severely affects the outcome of people with psychotic disorders, yet there is a lack of treatments. To address this, in 2019 the National Health Service (NHS) Cannabis Clinic for Psychosis (CCP) was developed to support adults suffering from psychosis to reduce and/or stop their cannabis use.
Aims
Examine outcome data from the first 46 individuals to complete the CCP's intervention.
Method
The sample (N = 46) consisted of adults (aged ≥ 18) with psychosis under the care of the South London and Maudsley NHS Foundation Trust, referred to the CCP between January 2020 and February 2023, who completed their intervention by September 2023. Clinical and functional measures were collected before (T0) and after (T1) the CCP intervention (one-to-one sessions and peer group attendance). Primary outcomes were changes in the Cannabis Use Disorders Identification Test-Revised (CUDIT-R) score and pattern of cannabis use. Secondary outcomes included T0–T1 changes in measures of delusions, paranoia, depression, anxiety and functioning.
Results
A reduction in the mean CUDIT-R score was observed between T0 (mean difference = 17.10, 95% CI = 15.54–18.67) and T1, with 73.91% of participants achieving abstinence and 26.09% reducing the frequency and potency of their use. Significant improvements in all clinical and functional outcomes were observed, with 90.70% being in work or education at T1 compared with 8.70% at T0. The variance in CUDIT-R scores explained between 34 and 64% of the variance in our secondary measures.
Conclusions
The CCP intervention is a feasible strategy to support cannabis use cessation/reduction and improve clinical and functional outcomes of people with psychotic disorders.
This review examines the relationship between long-term antipsychotic use and individual functioning, emphasizing clinical implications and the need for personalized care. The initial impression that antipsychotic medications may worsen long-term outcomes is critically assessed, highlighting the confounding effects of illness trajectory and individual patient characteristics. Moving beyond a focus on methodological limitations, the discussion centers on how these findings can inform clinical practice, keeping in consideration that a subset of patients with psychotic disorders are on a trajectory of long-term remission and that for a subset of patient the adverse effects of antipsychotics outweigh potential benefits. Key studies such as the OPUS study, Chicago Follow-up study, Mesifos trial, and RADAR trial are analyzed. While antipsychotics demonstrate efficacy in short-term symptom management, their long-term effects on functioning are less obvious and require careful interpretation. Research on long-term antipsychotic use and individual functioning isn't sufficient to favor antipsychotic discontinuation or dose reduction below standard doses for most patients, but it is sufficient to highlight the necessity of personalization of clinical treatment and the appropriateness of dose reduction/discontinuation in a considerable subset of patients.
Trauma-related beliefs are theorized to contribute to the development and maintenance of psychosis symptoms. However, the evidence for this proposal has yet to be systematically reviewed. This article is the first to synthesize and meta-analyze studies examining associations between trauma-related beliefs and psychosis symptoms, including hallucinations, delusions, paranoia, and negative symptoms. A systematic database search of Medline, PsychINFO, Embase, Web of Science, CINHAL, and Cochrane identified a total of 15 articles that met the inclusion criteria for systematic review and 11 articles which met the inclusion criteria for meta-analysis. Separate random-effects meta-analyses were conducted for each psychosis symptom. Meta-analytic findings demonstrated a small to moderate association between trauma-related beliefs and hallucination severity (k = 7, r = 0.25, 95% CI 0.10–0.39), a moderate to large association with delusion severity (k = 8, r = 0.43, 95% CI 0.31–0.54), and large association with paranoia severity (k = 4, r = 0.58, 95% CI 0.49–0.66). Narrative synthesis findings indicate that evidence for an association between negative symptoms and trauma-related beliefs was inconclusive. The meta-analytic findings provide support for an association between trauma-related beliefs and positive psychosis symptoms. This provides evidence suggesting trauma therapies for psychosis that target these beliefs may improve distressing psychosis. However, further research adopting longitudinal designs and controlling for confounders is required to better establish causality, including mediation analysis of therapy trials.
Suicide accounts for a proportion of the early mortality in people affected by psychotic disorders. The early phase of illness can represent a particularly high-risk time for suicide. Therefore, in a cohort of young people presenting with first-episode psychosis, this study aimed to determine: (i) the prevalence of suicidal ideation, intent with plan and self-harm and any associated demographic or clinical factors and (ii) the prevalence of depressive symptoms and any associated demographic or clinical factors.
Methods:
Young people with a first episode of psychosis attending the Early Psychosis Prevention and Intervention Centre in Melbourne were included. Suicidal behaviours were recorded using a structured risk assessment – ‘Clinical Risk Assessment and Management in the Community’, and depressive symptoms were measured using the PHQ-9.
Results:
A total of 355 young people were included in the study. 57.2% were male, 95.4% were single and over one quarter were migrants. At the time of presentation, 34.6% had suicidal ideation, 6.2% had suicidal intent with a plan, and 21.4% had engaged in self-harm before their presentation. Combined, 39.7% (n = 141) presented with suicidal ideation, intent with plan or self-harm. A total of 71.5% (n = 118) had moderately severe or severe depressive symptoms, which was strongly associated with suicidal ideation or behaviours at the time of presentation (OR = 4.21, 95% C.I. 2.10–8.44).
Conclusions:
Depressive symptoms, self-harm and suicidal behaviours are commonly present in the early phases of a psychotic disorder, which has important clinical implications for assessment and management.
The association between cannabis and psychosis is established, but the role of underlying genetics is unclear. We used data from the EU-GEI case-control study and UK Biobank to examine the independent and combined effect of heavy cannabis use and schizophrenia polygenic risk score (PRS) on risk for psychosis.
Methods
Genome-wide association study summary statistics from the Psychiatric Genomics Consortium and the Genomic Psychiatry Cohort were used to calculate schizophrenia and cannabis use disorder (CUD) PRS for 1098 participants from the EU-GEI study and 143600 from the UK Biobank. Both datasets had information on cannabis use.
Results
In both samples, schizophrenia PRS and cannabis use independently increased risk of psychosis. Schizophrenia PRS was not associated with patterns of cannabis use in the EU-GEI cases or controls or UK Biobank cases. It was associated with lifetime and daily cannabis use among UK Biobank participants without psychosis, but the effect was substantially reduced when CUD PRS was included in the model. In the EU-GEI sample, regular users of high-potency cannabis had the highest odds of being a case independently of schizophrenia PRS (OR daily use high-potency cannabis adjusted for PRS = 5.09, 95% CI 3.08–8.43, p = 3.21 × 10−10). We found no evidence of interaction between schizophrenia PRS and patterns of cannabis use.
Conclusions
Regular use of high-potency cannabis remains a strong predictor of psychotic disorder independently of schizophrenia PRS, which does not seem to be associated with heavy cannabis use. These are important findings at a time of increasing use and potency of cannabis worldwide.
Cognitive impairment constitutes a prevailing issue in the schizophrenia spectrum, severely impacting patients' functional outcomes. A global cognitive score, sensitive to the stages of the spectrum, would benefit the exploration of potential factors involved in the cognitive decline.
Methods
First, we performed principal component analysis on cognitive scores from 768 individuals across the schizophrenia spectrum, including first-degree relatives of patients, individuals at ultra-high risk, who had a first-episode psychosis, and chronic schizophrenia patients, alongside 124 healthy controls. The analysis provided 10 g-factors as global cognitive scores, validated through correlations with intelligence quotient and assessed for their sensitivity to the stages on the spectrum using analyses of variance. Second, using the g-factors, we explored potential mechanisms underlying cognitive impairment in the schizophrenia spectrum using correlations with sociodemographic, clinical, and developmental data, and linear regressions with genotypic data, pooled through meta-analyses.
Results
The g-factors were highly correlated with intelligence quotient and with each other, confirming their validity. They presented significant differences between subgroups along the schizophrenia spectrum. They were positively correlated with educational attainment and the polygenic risk score (PRS) for cognitive performance, and negatively correlated with general psychopathology of schizophrenia, neurodevelopmental load, and the PRS for schizophrenia.
Conclusions
The g-factors appeared as valid estimators of global cognition, enabling discerning cognitive states within the schizophrenia spectrum. Educational attainment and genetics related to cognitive performance may have a positive influence on cognitive functioning, while general psychopathology of schizophrenia, neurodevelopmental load, and genetic liability to schizophrenia may have an adverse impact.
This chapter describes Psychosis Identification and Early Referral (PIER), a clinical and public health system for identifying, treating, and rehabilitating young people at risk for major psychosis and psychotic disorders. A specialized clinical team educates key sectors of the community in identifying very early signs and symptoms of a likely psychosis in youth ages 10–25. The team then rigorously assesses those referred and found at risk and provides family-aided assertive community treatment. This model was originally developed for schizophrenia in young adults, and it has been adapted for the much younger and less seriously symptomatic and disabled at-risk population. The model includes flexible, in-vivo clinical treatment, family psychoeducation, cognitive-behavioral therapy, occupational therapy, supported education and supported employment, and psychiatric and nursing care. PIER has been tested across six population-representative sites in the United States; within testing periods, very few participating youths have experienced psychosis and about 90 percent are in school or working. It has been replicated widely enough that it is available to over 15 percent of the US population.
Transition to psychosis rates within ultra-high risk (UHR) services have been declining. It may be possible to ‘enrich’ UHR cohorts based on the environmental characteristics seen more commonly in first-episode psychosis cohorts. This study aimed to determine whether transition rates varied according to the accumulated exposure to environmental risk factors at the individual (migrant status, asylum seeker/refugee status, indigenous population, cannabis/methamphetamine use), family (family history or parental separation), and neighborhood (population density, social deprivation, and fragmentation) level.
Methods
The study included UHR people aged 15–24 who attended the PACE clinic from 2012 to 2016. Cox proportional hazards models (frequentist and Bayesian) were used to assess the association between individual and accumulated factors and transition to psychosis. UHR status and transition was determined using the CAARMS. Benjamini–Hochberg was used to correct for multiple comparisons in frequentist analyses.
Results
Of the 461 young people included, 55.5% were female and median follow-up was 307 days (IQR: 188–557) and 17.6% (n = 81) transitioned to a psychotic disorder. The proportion who transitioned increased incrementally according to the number of individual-level risk factors present (HR = 1.51, 95% CIs 1.19–1.93, p < 0.001, pcorr = 0.01). The number of family- and neighborhood-level exposures did not increase transition risk (p > 0.05). Cannabis use was the only specific risk factor significantly associated with transition (HR = 1.89, 95% CIs 1.22–2.93, pcorr = 0.03, BF = 6.74).
Conclusions
There is a dose–response relationship between exposure to individual-level psychosis-related environmental risk factors and transition risk in UHR patients. If replicated, this could be incorporated into a novel approach to identifying the highest-risk individuals within clinical services.