The role of depression in unnatural death: A case-based retrospective study.

BACKGROUND: Depression affects the life of millions around the globe and perhaps also the manner of death. This study examined the role of depression in specific causes of unnatural death and whether alcohol and substance use affect this relationship, in one locality in Scotland. METHODS: The research used a retrospective case-based study approach to analyse 168 cases, quantifying data reported in mortuary files to allow for quantitative statistical analysis of associations and differences amongst the variables. RESULTS: A diagnosis of depression was associated with a higher likelihood of unnatural death due to suicide, drugs or homicide. A diagnosis of substance abuse was associated with a diagnosis of depression and with an increased likelihood of death due to suicide or drugs. A diagnosis of alcohol abuse was associated with a reduced likelihood of a diagnosis of depression but was associated with an increased likelihood of suicide. LIMITATIONS: This study relied on a small sample from one locality in Scotland which limited the ability to generalise the results and the retrospective case-based design also limited the potential for checking data accuracy or to consider temporal relationships, which limited the ability to interpret causality. CONCLUSIONS: This study found that there was a relationship between depression and unnatural death, which was mediated by alcohol and substance use. The importance of this study lies within the recognition of these relationships which identified the complexities of these relationships but suggested that some unnatural deaths within this population could be prevented.

Intra-individual and inter-individual variation in breath alcohol pharmacokinetics: Variation over three visits.

Eleven male and 7 female student subjects underwent serial Breath Alcohol Concentration (BrAC) measurements after being given alcohol as 13% white wine (5.7 ml/kg for males and 4.7 ml/kg for females) in a fasting state on three separate occasions. BrAC versus time curves were constructed for each subject and the values of peak BrAC (Cmax), theoretical BrAC extrapolated at zero time (Co), time taken to reach peak (Tmax) and rate of elimination (ß) from breath were recorded directly from the curves. Average Intra-individual variation for each individual between the 3 visits (for males and females, respectively) was 5.6% and 8% for Co, 12% and 13% for Cmax, 42% and 37% for Tmax and 11% and 13% for ß. Inter-individual variation (for males and females) was 7.5% and 13% for Co, 16% and 15% for Cmax, 43% and 46% for Tmax and 21% and 15% for ß. Average elimination rates in males (5.3 µg/100 ml breath/h, range 4-7.7) and females (5.6 µg/100 ml breath/h, range 4-7) were not significantly different. Widmark factors calculated by various established mathematical methods were 0.71-0.81 in males and 0.59-0.68 in females, higher than the originally quoted mean experimental levels.

Intra-individual and inter-individual variation in breath alcohol pharmacokinetics: the effect of short-term variation.

Ten male and 8 female students underwent serial breath alcohol concentration (BrAC) measurements on a CAMIC Datamaster on two consecutive occasions, early evening and again the following morning. Subjects were fasted for 6 h before receiving alcohol as white wine (12.5% by volume) at doses of 38-45 g for males and 26-37 g for females, consumed over 10 min. Specific individual doses were calculated individually from height and weight (according to the Forrest Method) to give target C0 breath alcohol concentrations of 35 µg/100 ml breath in males and 31 µg/100 ml breath in females. BrAC versus time curves were constructed for each subject and the values of peak BrAC (Cmax), BrAC extrapolated at zero time (C0), time taken to reach peak (Tmax) and rate of elimination (ß) were recorded directly from the curves. Values of C0 taken from the BrAC-time curves varied widely, from 21 to 47 µg/100 ml on visit 1 and from 22 to 45 µg/100 ml on visit 2. Widmark Factors calculated from these C0 values averaged 0.74 (range, 0.59-1.06) in males and 0.73 (range, 0.58-1.05) in females. Elimination rate was higher in the morning than evening in both males (7.4 versus 5.7 µg/100 ml/h) and females (6.9 versus 5.8 µg/100 ml/h). Elimination rates in males and females were not significantly different. Total body water, measured by electronic scales, averaged 58.7% (range, 56.6-63%) in males and 48.3% (range, 40.9-57.6%) in females. Widmark Factors calculated by various established mathematical methods were 0.73-0.77 in males and 0.61-0.64 in females.

Intra-individual and inter-individual variation in breath alcohol pharmacokinetics: The effect of food on absorption.

Eight male and 8 female subjects underwent serial breath alcohol concentration (BrAC) measurements in the fasting state, following a snack of crisps and following a light meal. BrAC versus time curves were constructed for each subject and the values of peak BrAC (C(max)), theoretical (extrapolated) BrAC at zero time (C(0)), time taken to reach peak (T(max)) and rate of elimination (ß) were recorded directly from the curves. In all subjects values of C(0) extrapolated from the post-meal BrAC-time curves were significantly lower than in the fasting and snack fed states. Since Widmark factor (W.F.) is inversely proportional to C(0), values of WF calculated from extrapolated C(0) after a meal were spuriously high. WF obtained from the fasting BrAC-time curves were usually only slightly higher than those calculated by the Forrest mathematical method. C(max) was highest in fasting subjects (mean 30.5, range 22.5-42µg/100ml) and lowest after a meal (mean 21.4, range 13.5-32µg/100ml). T(max) was shortest after a meal and also remarkably consistent (mean 22, range 17-50min). 'Overshoot' was seen in most fasting subjects within about 40min of consuming alcohol. Elimination of alcohol from breath was slightly lower after a meal (mean 5.4, range 3.9-8.5µg/100ml/h) than after either fasting (mean 6, range 4.7-7.3µg/100ml/h) or a snack (mean 6, range 4.4-8.8µg/100ml/h). The availability of alcohol for absorption (as a percentage of the predicted value) was almost complete after fasting or a snack but after a meal was reduced to only 66% in females and 71% in males. The practical significance of this much reduced peak BrAC after food occurs in relation to forward or back calculations and cases involving post-accident drinking ("the hip flask" defence) as ingestion of a meal before or with alcohol is a common social situation which may complicate BAC estimation in some medico-legal cases.