The Bristol stool scale is a diagnostic medical tool designed to classify the form of human feces into seven categories. It is used in both clinical and experimental fields. The seven types of stool are:

Scale 1: Separate hard lumps, like nuts (hard to pass), also known as goat feces or sausage-shaped, but lumpy.

Scale 2: Like a sausage but with cracks on its surface or like a sausage or snake, smooth and soft.

Scale 3: Soft blobs with clear cut edges (passed easily). Scale 4: Fluffy pieces with ragged edges, a mushy stool even watery, no solid pieces, entirely liquid.

Scale 1 indicate constipation, Scale 2 being the ideal stools as they are easy to defecate while not containing excess liquid, Scale 3 tending towards diarrhea, and Scale 4 indicate diarrhea.

A self-report questionnaire that assesses sleep quality over a 1-month time interval. The measure consists of 19 individual items, creating 7 components that produce one global score, and takes 5-10 minutes to complete. Developed by researchers at the University of Pittsburgh, the PSQI is intended to be a standardized sleep questionnaire for clinicians and researchers to use with ease and is used for multiple populations. The questionnaire has been used in many settings, including research and clinical activities, and has been used in the diagnosis of sleep disorders. Clinical studies have found the PSQI to be reliable and valid in the assessment of sleep problems to some degree, but more so with self-reported sleep problems and depression-related symptoms than actigraphic measures.

Neuropeptide Y (NPY) is a 36 amino-acid neuropeptide that is involved in various physiological and homeostatic processes in both the central and peripheral nervous systems. NPY has been identified as the most abundant peptide present in the mammalian central nervous system, which consists of the brain and spinal cord. It is secreted alongside other neurotransmitters such as glutamate.

Substance P is a bioactive 11-amino acid peptide (Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met-amide) first isolated in 1931 from brain and intestine. The peptide is involved in many physiological processes including pain modulation, smooth muscle contraction, blood pressure control, kidney function and water homeostasis.Substance P is widely distributed in numerous tissues and body fluids including the central and peripheral nervous system, gastrointestinal tract, respiratory tract, visual system and circulatory system.