Neuromelanin levels in individuals with substance use disorders: A systematic review and meta-analysis.

Dopamine's role in addiction has been extensively studied, revealing disruptions in its functioning throughout all addiction stages. Neuromelanin in the substantia nigra (SN) may reflect dopamine auto-oxidation, and can be quantified using neuromelaninsensitive magnetic resonance imaging (neuromelanin-MRI) in a non-invasive manner.In this pre-registered systematic review, we assess the current body of evidence related to neuromelanin levels in substance use disorders, using both post-mortem and MRI examinations. The systematic search identified 10 relevant articles, primarily focusing on the substantia nigra. An early-stage meta-analysis (n = 6) revealed varied observations ranging from standardized mean differences of -3.55 to +0.62, with a pooled estimate of -0.44 (95 % CI = -1.52, 0.65), but there was insufficient power to detect differences in neuromelanin content among individuals with substance use disorders. Our gap analysis highlights the lack of sufficient replication studies, with existing studies lacking the power to detect a true difference, and a complete lack of neuromelanin studies on certain substances of clinical interest. We provide recommendations for future studies of dopaminergic neurobiology in addictions and related psychiatric comorbidities.

Cognitive behavioral therapy for managing depressive and anxiety symptoms after brain injury: a meta-analysis.

BACKGROUND: Individuals with traumatic brain injury (TBI) are at increased risk of depression and anxiety, leading to impaired recovery. While cognitive-behavioral therapy (CBT) addresses anxiety and depression maintenance factors, its efficacy among those with TBI has not been clearly demonstrated. This review aims to bridge this gap in the literature. METHODS: Several databases, including Medline, PsycInfo and EMBASE, were used to identify studies published between 1990 and 2021. Studies were included if: (1) trials were randomized controlled trials (RCT) involving CBT-based intervention targeting anxiety and/or depression; (2) participants experienced brain injury at least 3-months previous; (3) participants were ≥18 years old. An SMD ± SE, 95% CI and heterogeneity were calculated for each outcome. RESULTS: Thirteen RCTs were included in this meta-analysis. The pooled-sample analyses suggest that CBT interventions had small immediate post-treatment effects on reducing depression (SMD ± SE: 0.391 ± 0.126, p < 0.005) and anxiety (SMD ± SE: 0.247 ± 0.081, p < 0.005). Effects were sustained at a 3-months follow-up for depression. A larger effect for CBT was seen when compared with supportive therapy than control. Another sub-analysis found that individualized CBT resulted in a slightly higher effect compared to group-based CBT. CONCLUSION: This meta-analysis provides substantial evidence for CBT in managing anxiety and depression post-TBI.

65 years of research on dopamine's role in classical fear conditioning and extinction: A systematic review.

Dopamine, a catecholamine neurotransmitter, has historically been associated with the encoding of reward, whereas its role in aversion has received less attention. Here, we systematically gathered the vast evidence of the role of dopamine in the simplest forms of aversive learning: classical fear conditioning and extinction. In the past, crude methods were used to augment or inhibit dopamine to study its relationship with fear conditioning and extinction. More advanced techniques such as conditional genetic, chemogenic and optogenetic approaches now provide causal evidence for dopamine's role in these learning processes. Dopamine neurons encode conditioned stimuli during fear conditioning and extinction and convey the signal via activation of D1-4 receptor sites particularly in the amygdala, prefrontal cortex and striatum. The coordinated activation of dopamine receptors allows for the continuous formation, consolidation, retrieval and updating of fear and extinction memory in a dynamic and reciprocal manner. Based on the reviewed literature, we conclude that dopamine is crucial for the encoding of classical fear conditioning and extinction and contributes in a way that is comparable to its role in encoding reward.

The effect of neuropathic pain treatments on pain interference following spinal cord injury: A systematic review.

CONTEXT: Neuropathic pain is a common and debilitating condition following SCI. While treatments for neuropathic pain intensity have been reviewed, the impact on pain interference has not been summarized. OBJECTIVE: To systematically review the effect of neuropathic pain interventions on pain interference in individuals with spinal cord injury. METHODS: This systematic review included randomized controlled trials and quasi-experimental (non-randomized) studies which assessed the impact of an intervention on pain interference in individuals with spinal cord injury and neuropathic pain. Articles were identified by searching MEDLINE (1996 to April 11, 2022), EMBASE (1996 to April 11, 2022), PsycInfo (1987 to April, week 2, 2022). Studies were assessed for methodologic quality using a modified GRADE approach and were given quality of evidence (QOE) scores on a 4-point scale ranging from very low to high. RESULTS: Twenty studies met the inclusion criteria. These studies fell into the following categories: anticonvulsants (n = 2), antidepressants (n = 1), analgesics (n = 1), antispasmodics (n = 1), acupuncture (n = 2), transcranial direct current stimulation (n = 1), active cranial electrotherapy stimulation (n = 2), transcutaneous electrical nerve stimulation (n = 2), repetitive transcranial magnetic stimulation (n = 1), functional electrical stimulation (n = 1), meditation and imagery (n = 1), self-hypnosis and biofeedback (n = 1), and interdisciplinary pain programs (n = 4). CONCLUSION: When considering studies of moderate to high quality, pregabalin, gabapentin, intrathecal baclofen, transcranial direct current stimulation, and transcutaneous electrical nerve stimulation (in 1 of 2 studies) were shown to have beneficial effects on pain interference. However, due to the low number of high-quality studies further research is required to confirm the efficacy of these interventions prior to recommending their use to reduce pain interference.

Internet-based sexual health resources for those living with spinal cord injury: A content analysis.

CONTEXT: Spinal cord injuries (SCIs) disrupt physiological functioning which can significantly impact sexuality. Those with SCI may rely heavily on Internet sexual health resources for many reasons. Evaluation of current internet health resources is warranted to identify the gaps in the literature. OBJECTIVES: The aim of this study was to conduct a purposive review of available Internet sexual health resources for those with SCI. METHODS: A Google search was completed with search terms such as: "SCI and sexual functioning", "SCI and sexuality", "SCI and pregnancy" and "SCI and sexual pleasure". Resources were selected if they: (1) provided sexual health education to those with SCI; (2) were designed to increase skills-based learning or influence attitudes and beliefs; and (3) in English language. All identified resources were imported to NVivo 1.5.1 where a thematic content analysis was conducted. RESULTS: The search resulted in 123 resources meeting the criteria. The most common themes included: Sexual functioning (in 83.7% of resources), Reproductive health (67.5%) and Impact of Secondary Complications (61.8%). The least common themes were Psychosocial (24.4%), Stigma (13.8%), and Quality of Life (12.2%). No information was coded for LGBTQ+. DISCUSSION: Sexual health and SCI information focuses primarily on heterosexual males and specifically on sexual functioning. Resources addressing female sexuality were extremely limited and focused largely on reproduction. There was a complete absence of resource aimed to address LGBTQ+ people. CONCLUSION: The results demonstrate a need for Internet-based sexual health education resources to meet the needs of diverse individuals including women and gender non-conforming people.

Online psychosocial intervention for persons with spinal cord injury: A meta-analysis.

BACKGROUND: Delivery of psychosocial interventions via the Internet has the potential to overcome barriers and increase access; however, effectiveness is yet to be established among those with spinal cord injury (SCI). METHODS: The objective of this meta-analysis is to evaluate the efficacy of Internet-based psychosocial interventions on the symptoms of anxiety, depression, and pain amongst those with SCI. The databases Medline, PsycInfo, and EMBASE were used to locate studies published between 1990 and December 2020. A study was included if (1) the study involved the application of an online psychosocial intervention; (2) adults with SCI; and (3) reported outcomes on depression and/or anxiety. From each study, participant characteristics and study details were extracted. A standardized mean difference (SMD) ± standard error and 95% confidence interval (CI) was calculated for each outcome of interest and the results were pooled using a fixed-effects model. RESULTS: The search yielded 920 studies, of which five were included in the final meta-analysis; It was revealed that Internet-based psychosocial interventions had a small effect on reducing overall anxiety (SMD: 0.42 ± 0.09, p < 0.001) and depression (SMD: 0.41 ± 0.09, p < 0.001) symptoms at the end of the study period. Online psychosocial interventions also had a moderate effect in maintaining reduction of anxiety (SMD: 0.50 ± 0.1, p < 0.001) and depressive (SMD: 0.64 ± 0.10, p < 0.001) symptoms at 3-month follow-up. CONCLUSION: The results of this meta-analysis provide evidence for the use of internet-based psychosocial interventions to manage anxiety and depression symptoms among those with spinal cord injuries.

Cognitive -behavioral therapy for managing depressive and anxiety symptoms after stroke: a systematic review and meta-analysis.

BACKGROUND: Post-stroke anxiety and depression can be disabling and result in impaired recovery. Cognitive-behavioral therapy (CBT) has been demonstrated to be effective for anxiety and depression; however, determining its efficacy among those with stroke is warranted. Our objectives to evaluate CBT for anxiety and depression post-stroke . METHODS: This review was registered with PROSPERO (REG# CRD42020186324). Medline, PsycInfo, and EMBR Cochrane were used to locate studies published before May 2020, using keywords such as stroke and CBT. A study was included if: (1) interventions were CBT-based, targeting anxiety and/or depression; (2) participants experienced a stroke at least 3 months previous; (3) participants were at least 18 years old. Standardized mean differences ± standard errors and 95% confidence intervals were calculated, and heterogeneity was determined. The Cochrane Risk of Bias tool was used. RESULTS: The search yielded 563 articles, of which 10 (N = 672) were included;6 were randomized controlled trials. Primary reasons for exclusion included: (1) wrong population (2) insufficient data provided for a meta-analysis; (3) wrongoutcomes. CBT showed large effects on reducing overall anxiety (SMD ± SE: 1.01 ± 0.32, p < .001) and depression (SMD ± SE: 0.95 ± 0.22, p < .000) symptoms at the end of the studies. CBT moderately maintained anxiety (SDM ± SE: 0.779 ± 0.348, p ˂.025) and depression (SDM ± SE: 0.622 ± 0.285, p ˂ .029) scores after 3-months. Limitations included small sample size, limited comparators, and lack of follow-up data. CONCLUSION: The results of this meta-analysis provide substantial evidence for the use of CBTto manage post-stroke anxiety and depression.