Marginal FS was associated with 1.82 times higher odds of antidepressant use and 1.73 times higher odds of sedative use, while low FS was associated with 1.66 times higher odds of antidepressant use. There were no significant associations between FS and antipsychotic use in these models, and no significant associations between very low FS and any of the psychotropic medication outcomes. We next examined associations of FS with any psychotropic medication use, antidepressant use and sedative use, additionally adjusting for CESD and GAD-7 scores . Marginal FS remained associated with 1.93 times higher odds of any psychotropic medication use. The AORs for associations of marginal FS with antidepressant and sedative use were 1.64 and 1.42, respectively, although neither reached statistical significance. Associations between low FS and each psychotropic medication outcome were close to 1 , while very low FS was associated with lower odds of each outcome, with the association between very low FS and antidepressant use statistically significant . Of the other variables, higher incomes were consistently associated with lower odds of psychotropic medication use prior to adjusting for CESD and GAD-7 scores. Having an annual income of $12 001–24 000 remained significantly associated with lower odds of any psychotropic medication use and antidepressant use after adjusting for CESD and GAD-7 scores, compared to having an annual income ⩽$12 000. Age was positively associated with any psychotropic medication use, antidepressant use and sedative use , both before and after adjusting for CESD and GAD-7 scores. Self-identifying as African-American/Black was associated with lower odds of any psychotropic medication use, antidepressant use and sedative use, compared to self-identifying as non-Hispanic White . In the fully adjusted model, CESD and GAD-7 scores were positively associated with any psychotropic medication use, antidepressant use and sedative use.In this study of women with HIV in the USA,cost of vertical farming food insecurity was associated with the symptoms of common mental illness but displayed a complex relationship with psychotropic medication use.
Similar to previous studies , we found a dose–response relationship between food insecurity and symptoms of common mental illness. We hypothesised that associations between food insecurity and psychotropic medication use would reflect this dose–response relationship, but our findings suggest a more complex picture. While marginal FS was associated with significantly higher odds of taking any psychotropic medication, antidepressants and sedatives, the magnitude of the associations decreased as severity of food insecurity increased. Very low FS was associated with lower odds of psychotropic medication use after adjusting for CESD and GAD-7 scores . While there may be several possible explanations for this pattern of findings, it is most likely that people who experience very low FS find it difficult to engage in mental health care because of competing resource demands. Such individuals may find it difficult to access mental health services and therefore have fewer chances to be prescribed psychotropic medications. Alternatively, they may access care but find it more difficult to adhere to medication regimens and subsequently have prescriptions discontinued. This possibility is supported by previous studies. Food insecurity has consistently been associated with poor engagement in care among PLHIV, including missing clinic visits and sub-optimal adherence to medications . In qualitative studies, food-insecure PLHIV describe how hunger, exhaustion, pre-occupation with finding food and less money for transport erect major barriers to attending clinics . Similarly, in a nationally representative sample of non-elderly adults in the USA, individuals with severe mental illness who had very low FS were twice as likely to report being unable to afford mental health care, and 25% less likely to be using mental health services, compared to food-secure individuals with severe mental illness . Two studies in the USA have found that severe food insecurity was associated with higher rates of acute mental health care utilisation. Among outpatient users of mental health services, severe food insecurity was associated with five times the odds of having any psychiatric emergency room visit ; and among a national sample of homeless adults, food insufficiency was associated with three times higher odds of psychiatric hospitalisation .
Poor access to ambulatory outpatient mental health services among severely food-insecure individuals may therefore result in inadequate long-term symptom control and, consequently, greater acute mental health care utilisation – which is the same pattern that has been seen in studies of food insecurity and HIV care . Another key finding is that marginal FS remained associated with nearly twice the odds of any psychotropic medication use after adjusting for symptoms of depression and anxiety. This supports our hypothesis that among these women living with HIV, food insecurity, at least in a milder form, may be associated with being prescribed psychotropic medications independent of symptoms of common mental illness. This suggests that people experiencing complex social problems such as food insecurity may be prescribed psychotropic medications at a higher rate than those without such problems. This is supported by higher incomes also being associated with lower odds of psychotropic medication use in models additionally adjusted for CESD and GAD-7 scores. These findings indicate that there may be structural incentives and concomitant factors that favour the prescription of psychotropic medications for all forms of distress, regardless of the nature of the dominant contributing factors . As explained above, these factors may include the clinical training of prescribers, the absence of resources for social interventions and/ or the relative stability and provision that can accompany a psychiatric diagnosis through disability . Given that the data were cross-sectional, these possible explanations must be interpreted cautiously, and further research is needed. It remains possible that the causality runs in the reverse direction: people with symptoms of common mental illness significant enough to warrant treatment with psychotropic medications may be more likely to be food-insecure, and then may be referred to food assistance services that prevents them from experiencing the most severe form of food insecurity. Longitudinal studies investigating directionality and dominant mediating mechanisms are needed to comprehensively understand this association. Our study has other limitations. Greater clarity on this aspect of the findings would be helpful. Similarly, we have no data on access to mental health services and attendance at clinic appointments, which would clarify some of the mechanisms and explanations behind the findings. Third, we have no data on other mental health treatment modalities among these women, and no data on adherence to treatments, whether pharmacological or nonpharmacological. Measurement of these variables will be important for future studies. Finally, we were unable to adjust for any other symptoms of mental illness besides depression and anxiety because such data were not collected in the WIHS.Behavioral, cognitive, and neurobiological profiles of individuals with pathological gambling resemble those of individuals with substance use disorder, especially stimulant addiction . As a consequence, pathological gambling was recently reclassified as an addiction disorder in the DSM-5 .
However, it is still unclear whether some of the dopamine abnormalities that characterize substance use disorder are also present in pathological gambling. The current study examined the role of dopamine synthesis capacity in pathological gambling. Below, we highlight central findings linking altered dopamine function with substance addiction before reviewing existing evidence of altered dopamine function in pathological gambling. Converging evidence from various lines of research indicates that substance use disorder is characterized by a decrease in striatal dopamine D2/D3 receptor availability , even though this reduction is more consistently observed among stimulant users than in individuals with opiate, nicotine, or cannabis dependence . In humans, this has been evidenced by cross-sectional studies using [11C]raclopride positron emission tomography and single-photon emission computed tomography imaging techniques . In addition, human studies focusing on dopamine synthesis capacity, measured with [18F]fluoro-levo-dihydroxyphenylalanine PET, have revealed either low or unaltered dopamine synthesis capacity across various substance use disorders . Whether observed differences in D2/D3 receptor availability are a cause or consequence of drug addiction, and how it interacts with presynaptic dopamine function, is an area of active research. Longitudinal studies in animals have revealed that diminished baseline availability of striatal dopamine D2/D3 receptors is both a predictor and a consequence of continued drug use. For example,vegetables vertical farming lower baseline availability of striatal dopamine D2/D3 receptors in drug-naïve monkeys predicts high rates of subsequent cocaine self-administration . Longitudinal scanning further reveals reduced D2/D3 receptor ligand binding following repeated drug exposure . Micro-PET studies in rats have confirmed and extended these findings by showing that high impulsivity traits are associated with low dopamine D2/D3 receptor availability and predispose to the development of drug addiction . These findings concur with human studies showing that trait impulsivity is a vulnerability marker for addiction , although—in contrast to animal research—the direction of the association with dopamine D2/D3 receptors is less clear. Indeed, whereas some studies have reported positive correlations in healthy control subjects , other studies have reportednegative correlations in HCs and methamphetaminedependent users . Studies focusing on targets of dopamine functioning have so far led to different results in pathological gambling compared with stimulant dependence. In fact, all PET studies in pathological gambling have failed to reveal abnormal dopamine D2/D3 receptor availability in pathological gamblers relative to HCs . Despite this lack of group differences, two studies found a negative correlation between baseline dopamine D2/D3 receptor binding in the ventral striatum and trait impulsivity in PGs .
Similarly, PET studies investigating gambling-induced dopamine release have failed to reveal overall group differences but have shown correlations with relevant measures related to gambling severity, excitement, and performance . Currently, direct evidence for abnormal dopamine functioning in pathological gambling comes exclusively from studies showing altered responsiveness to dopaminergic drugs . In particular, PGs were shown to display greater amphetamine-induced dopamine release in the dorsal striatum, as measured with PET imaging using the D3 receptor–preferring radioligand [11C]–4- Propyl-9-hydroxynaphthoxazine, compared with HCs . This increased dopaminergic response echoes a recurrent clinical observation in Parkinson’s disease: following dopaminergic treatment aimed at compensating for dopamine cell loss, a subset of patients with Parkinson’s disease develop gambling disorder symptoms . These observations suggest that enhanced dopaminergic transmission may represent a biological substrate of gambling disorder. Thus, so far nearly all dopamine PET studies on pathological gambling have focused on dopamine D2/D3 receptors, investigating either receptor availability or the effects of dopaminergic drugs and gambling tasks. To date, there has been a paucity of research investigating dopamine synthesis capacity in PGs, with only one recent study reporting no difference with HCs . Yet, increased dopamine synthesis capacity has been associated with increased behavioral disinhibition and financial extravagance in healthy subjects and patients with Parkinson’s disease . Here we used dynamic [ 18F]DOPA PET imaging to investigate striatal dopamine synthesis capacity in male PGs and HCs matched for age, education, and an estimate of verbal IQ.In total, 15 PGs and 15 HCs were recruited. All HCs and 13 PGs had also participated in a previous pharmaco-functional magnetic resonance imaging study . The other 2 PGs were newly recruited. PGs were recruited through advertisement and addiction treatment centers, and they reported not to be medicated or in treatment for their gambling at the time of the PET study. HCs were recruited through advertisement. All subjects who had participated in the pharmaco-fMRI study underwent a structured psychiatric interview [Mini International Neuropsychiatric Interview–Plus, ] administered by a medical doctor prior to the fMRI study. The 2 PGs who were newly recruited were also assessed with the Mini-International Neuropsychiatric Interview–Plus administered by a clinical psychologist. Subjects were excluded if they had a lifetime history of schizophrenia, bipolar disorder, attention-deficit/hyperactivity disorder, autism, bulimia, anorexia, anxiety disorder, or obsessive-compulsive disorder or if they had a past 6-month history of major depressive episode. Current or past-year substance use disorder was also an exclusion criterion, as assessed at the time of the PET study using the 10-item Drug Abuse Screening Test questionnaire . Based on this criterion, data from 2 PGs were not included in the main analyses because of meeting the DSM-IV-TR criteria for cannabis dependence during the past year. As assessed with the Mini-International Neuropsychiatric Interview–Plus interview, 1 of the excluded cannabisdependent PGs also had a history of cocaine dependence that lasted for 1.5 years and ended 5.5 years prior to the PET study. In addition, 1 included PG had histories of alcohol and cocaine dependence that lasted for 1 year and ended 8 and 15 years prior to the PET study, respectively.