Although there is a rich body of research available regarding the effect of acute and chronic khat dosing in animal models, research on the behavioral and cognitive effects of khat in human subjects is not extensive and several of the available studies have been done only in the context of observational and single-case studies. In light of the absence of a substantial literature on the neurobehavioral deficits associated with khat use and to provide a context that could be used to identify themes for future research we review previous research that has focused on other stimulant drugs. This review highlights multiple areas of neurocognitive deficit that have been identified in previous studies of individuals who have been chronic users of stimulants, such as amphetamines and methamphetamines. The review highlights a substantial body of evidence demonstrating a wide range of learning and memory impairments including deficits that persist during abstinence from active drug use. This review does not imply a similar khat effect, but due to some similarities pharmacologically between the active components of khat (cathinone and cathine) and amphetamines, future studies examining these same domains of cognitive functioning in chronic khat users and abstinent khat users appears to be warranted, if possible using some of the same or similar laboratory measures.

BackgroundThere are compelling theoretical and empirical reasons that link household food insecurity to mental distress in the setting where both problems are common. However, little is known about their association during pregnancy in Ethiopia.MethodsA cross-sectional study was conducted to examine the association of household food insecurity with mental distress during pregnancy. Six hundred and forty-two pregnant women were recruited from 11 health centers and one hospital. Probability proportional to size (PPS) and consecutive sampling techniques were employed to recruit study subjects until the desired sample size was obtained. The Self Reporting Questionnaire (SRQ-20) was used to measure mental distress and a 9-item Household Food Insecurity Access Scale was used to measure food security status. Descriptive and inferential statistics were computed accordingly. Multivariate logistic regression was used to estimate the effect of food insecurity on mental distress.ResultsFifty eight of the respondents (9 %) were moderately food insecure and 144 of the respondents (22.4 %) had mental distress. Food insecurity was also associated with mental distress. Pregnant women living in food insecure households were 4 times more likely to have mental distress than their counterparts (COR = 3.77, 95 % CI: 2.17, 6.55). After controlling for confounders, a multivariate logistic regression model supported a link between food insecurity and mental distress (AOR = 4.15, 95 % CI: 1.67, 10.32).ConclusionThe study found a significant association between food insecurity and mental distress. However, the mechanism by which food insecurity is associated with mental distress is not clear. Further investigation is therefore needed to understand either how food insecurity during pregnancy leads to mental distress or weather mental distress is a contributing factor in the development of food insecurity.

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Acute mental stressors have been implicated as variables that may deleteriously affect neuropsychological test performance by increasing distractibility and decreasing working memory function. This study examined 25 subjects with no known neurological or psychiatric impairment on a brief battery of neuropsychological measures on alternate days following either rest or induced mental stress in a counterbalanced design. The test battery consisted of the Rey Auditory-Verbal Learning Test, the Rey Complex Figure, and three Wechsler Memory Scale-III subtests (Logical Memory, Digit Span, and Visual Memory Span). The Ss average age was 24.8 years (S.D. = 10.1) and average education was 15.0 years (S.D. = 1.6). The mental stressor employed was a videotaped public-speaking exercise that has been shown in previous work to induce negative mood, cardiovascular reactivity, and perceived mental stress. Ss demonstrated statistically significant (P < .05) increases in negative mood, heart rate, diastolic blood pressure, and systolic blood pressure as well as elevated cortisol concentration following induced stress, suggesting substantially increased adrenocortical reactivity and cardiovascular stress response. There were, however, no statistically significant differences in any of the neuropsychological measures when stress versus rest days were compared. The results suggest that acute mental stressors may have no measurable effect on subsequent performance on selected neuropsychological tests in a normal population. Further work is suggested to determine whether pre-existing anxiety-related psychopathology or pre-existing neurological compromise might interact with induced mental stress to cause decrements in neuropsychological test performance.

Background: Khat is a psychostimulant plant widely used in Africa and its use has been growing rapidly in Europe and North America. Objectives: We investigated effects of chronic khat (Catha edulis) use on cardiovascular, adrenocortical, and psychological responses to acute stress. Methods: Chronic khat users and nonusers were compared on physiological measures and mood reports in a cross-sectional, mixed design. Measurements were conducted during 24-hour ambulatory monitoring and during a laboratory session. A total of 152 participants (58 women) were recruited by flyers posted around Sana’a University campus and the surrounding community in Sana’a, Yemen. Salivary cortisol and self-report measures were collected during a 24-hour ambulatory period prior to a lab testing session. In addition, blood pressures (BP), salivary cortisol, and mood measures were assessed during rest and in response to acute mental stress. Results: Khat users exhibited enhanced evening and attenuated morning cortisol levels, reflecting a blunted diurnal pattern of adrenocortical activity compared to nonusers. Khat users reported greater negative affect during the ambulatory period and during the laboratory session. In addition, they exhibited attenuated BP responses to stress. Conclusions and Scientific Significance: These novel results demonstrate altered adrenocortical activity and increased dysphoric mood among khat users. The extent to which these associations are due to effects of chronic khat use per se or instead reflect predisposing risk factors for khat use is yet to be determined.