Ketogenic-Mimicking Diet as a Therapeutic Modality for Bipolar Disorder: Biomechanistic Rationale and Protocol for a Pilot Clinical Trial

There is growing interest in the investigation of ketogenic diets as a potential therapy for bipolar disorder. The overlapping pharmacotherapies utilized for both bipolar disorder and seizures suggest that a mechanistic overlap may exist between these conditions, with fasting and the ketogenic diet representing the most time-proven therapies for seizure control. Recently, preliminary evidence has begun to emerge supporting a potential role for ketogenic diets in treating bipolar disorder. Notably, some patients may struggle to initiate a strict diet in the midst of a mood episode or significant life stressors. The key question addressed by this pilot clinical trial protocol is if benefits can be achieved with a less restrictive diet, as this would allow such an intervention to be accessible for more patients. Recent development of so-called ketone esters, that once ingested is converted to natural ketone bodies, combined with low glycemic index dietary changes has the potential to mimic two foundational components of therapeutic ketosis: high levels of ketones and minimal spiking of glucose/insulin. This pilot clinical trial protocol thus aims to investigate the effect of a 'ketogenic-mimicking diet' (combining supplementation of ketone esters with a low glycemic index dietary intervention) on neural network stability, mood, and biomarker outcomes in the setting of bipolar disorder. Positive findings obtained via this pilot clinical trial protocol may support future target engagement studies of ketogenic-mimicking diets or related ketogenic interventions. A lack of positive findings, in contrast, may justify a focus on more strict dietary interventions for future research.

Probing the Effects of Strong Electromagnetic Fields with Charge-Dependent Directed Flow in Pb-Pb Collisions at the LHC

The first measurement at the LHC of charge-dependent directed flow (v_{1}) relative to the spectator plane is presented for Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV. Results are reported for charged hadrons and D^{0} mesons for the transverse momentum intervals p_{T}>0.2  GeV/c and 3<p_{T}<6  GeV/c in the 5%-40% and 10%-40% centrality classes, respectively. The difference between the positively and negatively charged hadron v_{1} has a positive slope as a function of pseudorapidity η, dΔv_{1}/dη=[1.68±0.49(stat)±0.41(syst)]×10^{-4}. The same measurement for D^{0} and D[over ¯]^{0} mesons yields a positive value dΔv_{1}/dη=[4.9±1.7(stat)±0.6(syst)]×10^{-1}, which is about 3 orders of magnitude larger than the one of the charged hadrons. These measurements can provide new insights into the effects of the strong electromagnetic field and the initial tilt of matter created in noncentral heavy ion collisions on the dynamics of light (u, d, and s) and heavy (c) quarks. The large difference between the observed Δv_{1} of charged hadrons and D^{0} mesons may reflect different sensitivity of the charm and light quarks to the early time dynamics of a heavy ion collision. These observations challenge some recent theoretical calculations, which predicted a negative and an order of magnitude smaller value of dΔv_{1}/dη for both light flavor and charmed hadrons.

Evidence of Spin-Orbital Angular Momentum Interactions in Relativistic Heavy-Ion Collisions

The first evidence of spin alignment of vector mesons (K^{*0} and ϕ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ_{00} is measured at midrapidity (|y|<0.5) in Pb-Pb collisions at a center-of-mass energy (sqrt[s_{NN}]) of 2.76 TeV with the ALICE detector. ρ_{00} values are found to be less than 1/3 (1/3 implies no spin alignment) at low transverse momentum (p_{T}<2  GeV/c) for K^{*0} and ϕ at a level of 3σ and 2σ, respectively. No significant spin alignment is observed for the K_{S}^{0} meson (spin=0) in Pb-Pb collisions and for the vector mesons in pp collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.

Scattering Studies with Low-Energy Kaon-Proton Femtoscopy in Proton-Proton Collisions at the LHC

The study of the strength and behavior of the antikaon-nucleon (K[over ¯]N) interaction constitutes one of the key focuses of the strangeness sector in low-energy quantum chromodynamics (QCD). In this Letter a unique high-precision measurement of the strong interaction between kaons and protons, close and above the kinematic threshold, is presented. The femtoscopic measurements of the correlation function at low pair-frame relative momentum of (K^{+}p⊕K^{-}p[over ¯]) and (K^{-}p⊕K^{+}p[over ¯]) pairs measured in pp collisions at sqrt[s]=5, 7, and 13 TeV are reported. A structure observed around a relative momentum of 58  MeV/c in the measured correlation function of (K^{-}p⊕K^{+}p[over ¯]) with a significance of 4.4σ constitutes the first experimental evidence for the opening of the (K[over ¯]^{0}n⊕K^{0}n[over ¯]) isospin breaking channel due to the mass difference between charged and neutral kaons. The measured correlation functions have been compared to Jülich and Kyoto models in addition to the Coulomb potential. The high-precision data at low relative momenta presented in this work prove femtoscopy to be a powerful complementary tool to scattering experiments and provide new constraints above the K[over ¯]N threshold for low-energy QCD chiral models.

Measurement of ϒ(1S) Elliptic Flow at Forward Rapidity in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The first measurement of the ϒ(1S) elliptic flow coefficient (v_{2}) is performed at forward rapidity (2.5<y<4) in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The results are obtained with the scalar product method and are reported as a function of transverse momentum (p_{T}) up to 15  GeV/c in the 5%-60% centrality interval. The measured ϒ(1S)v_{2} is consistent with 0 and with the small positive values predicted by transport models within uncertainties. The v_{2} coefficient in 2<p_{T}<15  GeV/c is lower than that of inclusive J/ψ mesons in the same p_{T} interval by 2.6 standard deviations. These results, combined with earlier suppression measurements, are in agreement with a scenario in which the ϒ(1S) production in Pb-Pb collisions at LHC energies is dominated by dissociation limited to the early stage of the collision, whereas in the J/ψ case there is substantial experimental evidence of an additional regeneration component.

Investigations of Anisotropic Flow Using Multiparticle Azimuthal Correlations in pp, p-Pb, Xe-Xe, and Pb-Pb Collisions at the LHC

Measurements of anisotropic flow coefficients (v_{n}) and their cross-correlations using two- and multiparticle cumulant methods are reported in collisions of pp at sqrt[s]=13  TeV, p-Pb at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02  TeV, Xe-Xe at sqrt[s_{NN}]=5.44  TeV, and Pb-Pb at sqrt[s_{NN}]=5.02  TeV recorded with the ALICE detector. The multiplicity dependence of v_{n} is studied in a very wide range from 20 to 3000 particles produced in the midrapidity region |η|<0.8 for the transverse momentum range 0.2<p_{T}<3.0  GeV/c. An ordering of the coefficients v_{2}>v_{3}>v_{4} is found in pp and p-Pb collisions, similar to that seen in large collision systems, while a weak v_{2} multiplicity dependence is observed relative to nucleus-nucleus collisions in the same multiplicity range. Using a novel subevent method, v_{2} measured with four-particle cumulants is found to be compatible with that from six-particle cumulants in pp and p-Pb collisions. The magnitude of the correlation between v_{n}^{2} and v_{m}^{2}, evaluated with the symmetric cumulants SC(m,n) is observed to be positive at all multiplicities for v_{2} and v_{4}, while for v_{2} and v_{3} it is negative and changes sign for multiplicities below 100, which may indicate a different v_{n} fluctuation pattern in this multiplicity range. The observed long-range multiparticle azimuthal correlations in high multiplicity pp and p-Pb collisions can neither be described by pythia 8 nor by impact-parameter-Glasma, music, and ultrarelativistic quantum molecular dynamics model calculations, and hence, provide new insights into the understanding of collective effects in small collision systems.

First Observation of an Attractive Interaction between a Proton and a Cascade Baryon

This Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Ξ^{-}. The result is extracted from two-particle correlations of combined p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} pairs measured in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a standard deviation in the range [3.6, 5.3] is found. Since the measured p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} correlation is significantly enhanced with respect to the Coulomb prediction, the presence of an additional, strong, attractive interaction is evident. The data are compatible with recent lattice calculations by the HAL-QCD Collaboration, with a standard deviation in the range [1.8, 3.7]. The lattice potential predicts a shallow repulsive Ξ^{-} interaction within pure neutron matter and this implies stiffer equations of state for neutron-rich matter including hyperons. Implications of the strong interaction for the modeling of neutron stars are discussed.

Azimuthal Anisotropy of Heavy-Flavor Decay Electrons in p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Angular correlations between heavy-flavor decay electrons and charged particles at midrapidity (|η|<0.8) are measured in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV. The analysis is carried out for the 0%-20% (high) and 60%-100% (low) multiplicity ranges. The jet contribution in the correlation distribution from high-multiplicity events is removed by subtracting the distribution from low-multiplicity events. An azimuthal modulation remains after removing the jet contribution, similar to previous observations in two-particle angular correlation measurements for light-flavor hadrons. A Fourier decomposition of the modulation results in a positive second-order coefficient (v_{2}) for heavy-flavor decay electrons in the transverse momentum interval 1.5<p_{T}<4  GeV/c in high-multiplicity events, with a significance larger than 5σ. The results are compared with those of charged particles at midrapidity and those of inclusive muons at forward rapidity. The v_{2} measurement of open heavy-flavor particles at midrapidity in small collision systems could provide crucial information to help interpret the anisotropies observed in such systems.

D-Meson Azimuthal Anisotropy in Midcentral Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV

The azimuthal anisotropy coefficient v_{2} of prompt D^{0}, D^{+}, D^{*+}, and D_{s}^{+} mesons was measured in midcentral (30%-50% centrality class) Pb-Pb collisions at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02  TeV, with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays at midrapidity, |y|<0.8, in the transverse momentum interval 1<p_{T}<24  GeV/c. The measured D-meson v_{2} has similar values as that of charged pions. The D_{s}^{+} v_{2}, measured for the first time, is found to be compatible with that of nonstrange D mesons. The measurements are compared with theoretical calculations of charm-quark transport in a hydrodynamically expanding medium and have the potential to constrain medium parameters.

J/ψ Elliptic Flow in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

We report a precise measurement of the J/ψ elliptic flow in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The J/ψ mesons are reconstructed at midrapidity (|y|<0.9) in the dielectron decay channel and at forward rapidity (2.5<y<4.0) in the dimuon channel, both down to zero transverse momentum. At forward rapidity, the elliptic flow v_{2} of the J/ψ is studied as a function of the transverse momentum and centrality. A positive v_{2} is observed in the transverse momentum range 2<p_{T}<8  GeV/c in the three centrality classes studied and confirms with higher statistics our earlier results at sqrt[s_{NN}]=2.76  TeV in semicentral collisions. At midrapidity, the J/ψ  v_{2} is investigated as a function of the transverse momentum in semicentral collisions and found to be in agreement with the measurements at forward rapidity. These results are compared to transport model calculations. The comparison supports the idea that at low p_{T} the elliptic flow of the J/ψ originates from the thermalization of charm quarks in the deconfined medium but suggests that additional mechanisms might be missing in the models.

Anomalous Evolution of the Near-Side Jet Peak Shape in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV

The measurement of two-particle angular correlations is a powerful tool to study jet quenching in a p_{T} region inaccessible by direct jet identification. In these measurements pseudorapidity (Δη) and azimuthal (Δφ) differences are used to extract the shape of the near-side peak formed by particles associated with a higher p_{T} trigger particle (1<p_{T,trig}<8  GeV/c). A combined fit of the near-side peak and long-range correlations is applied to the data allowing the extraction of the centrality evolution of the peak shape in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV. A significant broadening of the peak in the Δη direction at low p_{T} is found from peripheral to central collisions, which vanishes above 4  GeV/c, while in the Δφ direction the peak is almost independent of centrality. For the 10% most central collisions and 1<p_{T,assoc}<2  GeV/c, 1<p_{T,trig}<3  GeV/c a novel feature is observed: a depletion develops around the center of the peak. The results are compared to pp collisions at the same center of mass energy and ampt model simulations. The comparison to the investigated models suggests that the broadening and the development of the depletion is connected to the strength of radial and longitudinal flow.

Flow Dominance and Factorization of Transverse Momentum Correlations in Pb-Pb Collisions at the LHC

We present the first measurement of the two-particle transverse momentum differential correlation function, P_{2}≡⟨Δp_{T}Δp_{T}⟩/⟨p_{T}⟩^{2}, in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV. Results for P_{2} are reported as a function of the relative pseudorapidity (Δη) and azimuthal angle (Δφ) between two particles for different collision centralities. The Δϕ dependence is found to be largely independent of Δη for |Δη|≥0.9. In the 5% most central Pb-Pb collisions, the two-particle transverse momentum correlation function exhibits a clear double-hump structure around Δφ=π (i.e., on the away side), which is not observed in number correlations in the same centrality range, and thus provides an indication of the dominance of triangular flow in this collision centrality. Fourier decompositions of P_{2}, studied as a function of the collision centrality, show that correlations at |Δη|≥0.9 can be well reproduced by a flow ansatz based on the notion that measured transverse momentum correlations are strictly determined by the collective motion of the system.

Ulcerative colitis and Crohn's disease: a comparison of the colorectal cancer risk in extensive colitis

The risk of developing colorectal cancer has been compared in two identically selected cohorts of patients with extensive Crohn's colitis (n = 125) and extensive ulcerative colitis (n = 486). In both groups the effects of selection bias have been reduced wherever possible. There was an 18-fold increase in the risk of developing colorectal cancer in extensive Crohn's colitis and a 19-fold increase in risk in extensive ulcerative colitis when compared with the general population, matched for age, sex, and years at risk. The absolute cumulative frequency of risk for developing colorectal cancer in extensive colitis was 8% at 22 years from onset of symptoms in the Crohn's disease group and 7% at 20 years from onset in the ulcerative colitis group. The relative risk of colorectal cancer was increased in both ulcerative colitis and Crohn's disease among those patients whose colitis started before the age of 25 years. Whether the absolute risk is greater in the younger age group or merely reflects that the expected number of carcinomas increases with age is uncertain. While there is an increased risk of developing colorectal cancer in extensive colitis the number of patients with Crohn's disease who actually develop colorectal cancer is small because many patients with extensive Crohn's colitis undergo colectomy early in the course of their disease to relieve persistent symptoms unresponsive to medical treatment.

Crohn's disease and colorectal cancer

The colorectal cancer risk in Crohn's disease eliminating all known biases was assessed in a cohort of 281 patients with Crohn's disease who resided in the West Midlands at the time of diagnosis, and were first seen within five years of onset of symptoms between 1945-1975. All patients were 15 years of age or more at onset and were followed up from 12-35 years (total 5213 person years at risk (PYR)). The colorectal cancer risk in the series compared with the risk in the general population was computed by applying sex and age specific PYRs to the date of death or end of the study period 31 December 1991. There were six colonic and two rectal cancers. Six of the eight colorectal cancers were diagnosed 20 or more years after the onset of Crohn's disease. The relative risk (RR) of colorectal cancer for the series as a whole was 3.4 (p < 0.001), with a fivefold excess in the colon, but no significant excess in the rectum. Patients with extensive colitis showed an 18-fold increase in risk (RR = 18.2, p < 0.001), which decreased with increasing age at onset. This study shows that there is a statistical excess risk of developing colorectal cancer in patients who develop their Crohn's disease at a young age of onset (less than 30 years of age).

Surgical resections in parous patients with distal ileal and colonic Crohn's disease

The surgical resection rates among parous women with distal ileal and colonic Crohn's disease have been compared with resection rates among distal ileal (n = 197) and colonic (n = 332) Crohn's disease patients. Thirty of 44 parous women with distal ileal Crohn's disease and 28 of 44 with colonic Crohn's disease had achieved their first pregnancy on average 8 years and 6.2 years respectively before the diagnosis of Crohn's disease was established. Resections for each patient were negatively correlated with parity in both groups. (Distal ileal disease (p = 0.034, rs = 0.3207), colonic disease (p = 0.051, rs = -0.2960)). Patients with distal ileal Crohn's disease and a history of pregnancy at diagnosis (n = 30, mean follow up = 15 years) had fewer resections/patient when compared with the published resection group: mean (SD); 1.17 (0.65) v 1.57 (1.05), p = 0.006. Patients with colonic Crohn's disease and a history of pregnancy at diagnosis (n = 28, mean follow up = 16.5 years) had fewer resections/patient when compared with the published resection group: mean (SD); 0.68 (0.77) v 1.05 (0.77), p = 0.019. In summary, patients with distal ileal and colonic Crohn's disease, who had been pregnant in the past subsequently need fewer surgical resections. Pregnancy could influence the natural history of Crohn's disease either by decreasing immune responsiveness or by retarding fibrous stricture formation, which is the commonest indication for surgical intervention.

Promoting physician-nurse collaboration throughout the organization

For health care institutions embracing the total quality approach to management, interdisciplinary collaboration focused on the processes associated with patient care is vital. To attain a vision of effective physician-nurse collaboration, specific initiatives at all levels of the University of Alberta Hospitals have helped to transform the vision into current reality.

Implementing shared governance: a false start

A case study of the implementation of shared governance in a large teaching hospital in Western Canada has been presented. The project was placed in jeopardy due to two major contingencies: turnover in the chief nursing executive position, and a sudden reduction in the operating budget of the nursing division necessitating significant layoffs. Other factors that threatened the survival of shared governance included lack of systematic, long-range planning; the number and diversity of major changes introduced concurrently in the nursing division; and insufficient support systems to sustain organizational change. In particular, some senior and first-line managers could not adapt to or accept the radical philosophical change and so they were unable to empower their staff and to provide the necessary reinforcement needed to ensure the success of shared governance. This combination of these factors contributed to the loss of momentum in the implementation of shared governance. Lowered morale in the wake of layoffs, together with union grievances, and lack of clarity of the role to be played by union representatives in shared governance produced conflict and confrontation within the nursing division and between union and management. Despite the difficulties encountered, there remains optimism and commitment to the challenge of making shared governance succeed. As this article goes to press, remarkable strides have been made in addressing the described issues. A task force composed primarily of staff nurses has developed a "customized" model of governance that meets the needs of the hospital and deals with the identified flaws of the first implementation attempt. The organization is optimistic that by taking time to develop a solid foundation for the proposed change and tending carefully to the details of decision-making processes, an effective structure to support the professional role of the nursing staff will be a reality.

Strategy for management of distal ileal Crohn's disease

We have determined the outcome of a defined policy for the management of distal ileal Crohn's disease using a prospective computer-based analysis of 139 patients diagnosed between 1970 and 1988 with a mean follow-up of 10 years. The policy in outline consists of conservative treatment for acute obstructive episodes, resection or strictureplasty for recurrent obstructive episodes, surgical treatment for abscess and fistula formation and specific medical treatment (corticosteroids, immunosuppressive therapy or metronidazole) for symptomatic non-obstructive disease. Twenty-nine patients had a benign course without resection. The remainder were treated surgically at some time but only 28 of these patients had specific treatment before operation. Thirty-three needed more than one resection and five needed more than three surgical procedures. Immediate, early or delayed surgical treatment did not affect the reoperation rates or the long-term outcome. Eleven patients died, ten of causes unrelated to Crohn's disease. Of the 128 living patients, 114 are fit and well, and only two are currently taking specific medication. Fourteen are unwell of whom six either need or have refused further surgery which could restore them to good health. This management policy has achieved excellent long-term results in nearly all patients, and our findings suggest that the timing of surgery and its nature are more important in determining outcome than specific medical therapy.

Prognosis after surgery for colonic Crohn's disease

The long-term prognosis including operation rates, the incidences of recurrent disease, morbidity and mortality and current status has been analysed in a group of 360 patients with Crohn's colitis grouped according to the primary site of macroscopic disease at diagnosis. The group has been followed from diagnosis for a mean period of 14.9 years. The overall operation rate was 76 per cent. Prolonged spontaneous or drug induced remission occurred at all sites: right-sided disease (11 per cent), extensive colonic disease (21 per cent) and left-sided disease (38 per cent). The cumulative reoperation rates at 5 and 10 years after right hemicolectomy were 26 and 46 per cent, after colectomy and ileorectal anastomosis 46 and 60 per cent, and after panproctocolectomy 10 and 21 per cent, respectively. There was a twofold excess mortality rate from related Crohn's disease deaths during the period of review, but the mortality rate has fallen with time. There have only been 11 related deaths in the last decade, of which eight were probably unavoidable. The current status of most patients is good, although treatment has included a permanent stoma in less than half (41 per cent) the patients still under review. Currently all but 14 patients are well and symptom-free and only 16 are receiving specific medical treatment. Until the aetiology of Crohn's colitis is understood, if medical treatment has failed to resolve symptoms, appropriate surgical treatment in experienced hands is an effective way of restoring patients with chronic persistent symptoms to good health.

Prognosis after surgery for colonic Crohn's disease

The long-term prognosis including operation rates, the incidences of recurrent disease, morbidity and mortality and current status has been analysed in a group of 360 patients with Crohn's colitis grouped according to the primary site of macroscopic disease at diagnosis. The group has been followed from diagnosis for a mean period of 14.9 years. The overall operation rate was 76 per cent. Prolonged spontaneous or drug induced remission occurred at all sites: right-sided disease (11 per cent), extensive colonic disease (21 per cent) and left-sided disease (38 per cent). The cumulative reoperation rates at 5 and 10 years after right hemicolectomy were 26 and 46 per cent, after colectomy and ileorectal anastomosis 46 and 60 per cent, and after panproctocolectomy 10 and 21 per cent, respectively. There was a twofold excess mortality rate from related Crohn's disease deaths during the period of review, but the mortality rate has fallen with time. There have only been 11 related deaths in the last decade, of which eight were probably unavoidable. The current status of most patients is good, although treatment has included a permanent stoma in less than half (41 per cent) the patients still under review. Currently all but 14 patients are well and symptom-free and only 16 are receiving specific medical treatment. Until the aetiology of Crohn's colitis is understood, if medical treatment has failed to resolve symptoms, appropriate surgical treatment in experienced hands is an effective way of restoring patients with chronic persistent symptoms to good health.

Mortality in Crohn's disease--a clinical analysis

We have examined the causes of death and the changing pattern of mortality over time among 769 patients with Crohn's disease under long-term review between 1944 and 1984. One hundred and fifty-six patients have died. The cause of death could not be classified in five. The deaths were divided into those related directly to Crohn's disease and unrelated deaths from incidental causes. The cause and age at death among 59 unrelated deaths was similar to that expected in the general population. The common causes of related deaths were sepsis, digestive tract cancer, pulmonary embolus and metabolic disorders. There were 30 deaths after surgery, usually from sepsis after emergency surgical treatment. There have been fewer deaths in recent years and the cause of death has altered. Sepsis and electrolyte imbalance have declined in importance and cancer of the digestive tract is now the most common cause of related death. Occasional death from sepsis occurs in elderly patients. Elective rather than emergency surgical treatment and the routine use of antimicrobial prophylaxis before surgery has probably reduced mortality. With the exception of cancer of the digestive tract the appropriate medical and surgical treatment of patients with Crohn's disease can eliminate excess mortality previously associated with the disorder.

Psychiatric screening for patients with faecal incontinence or chronic constipation referred for surgical treatment

Fifty patients attending for surgical treatment of chronic constipation (n = 21) or faecal incontinence (n = 29) were studied using two psychiatric screening tests: the Hospital Anxiety and Depression (HAD) scale and the General Health Questionnaire (GHQ). Each patient was assessed preoperatively and 6-12 months postoperatively. Results were compared with age and sex-matched controls (n = 50). Constipated patients had significantly higher HAD depression scores compared with controls (median and range): 6 (2-12) versus 4 (0-8), P less than 0.05. Constipated patients who were improved by operation (n = 13) had significantly lower preoperative HAD anxiety scores compared with those who were not improved (n = 8): 8 (3-14) versus 15 (10-19), P less than 0.01; they also had significantly lower HAD depression scores: 4 (2-12) versus 7 (5-11), P less than 0.05. Using these parameters incontinent patients did not differ from controls, but patients who had a bad result after operation (n = 15) had significantly higher HAD anxiety scores than those who obtained clinical benefit (n = 14): 10 (2-15) versus 6 (2-12), P less than 0.05; HAD depression scores were also greater: 5 (2-15) versus 3 (0-9), P less than 0.05; and GHQ scores were greater: 12 (0-47) versus 4 (0-41), P less than 0.05.