Chapter 72: Other Psychiatric Disorders

Feeding and eating disorders represent chronic psychiatric conditions with severe physical and mental health consequences, including among the highest mortality rates across all psychiatric illnesses. Anorexia nervosa involves severe caloric restriction resulting in dangerously low body weight accompanied by intense fear of weight gain and distorted body perception, with presentations ranging from purely restrictive patterns to binge-eating and purging subtypes. Bulimia nervosa manifests through repeated cycles of uncontrolled binge eating followed by compensatory behaviors including self-induced vomiting, laxative misuse, or excessive physical activity. Binge-eating disorder involves recurrent episodes of loss-of-control eating that cause marked distress but occur without the compensatory mechanisms seen in bulimia nervosa and frequently co-occurs with obesity. Avoidant or restrictive food intake disorder involves inability to meet nutritional requirements stemming from sensory sensitivities or anxiety about choking rather than body image concerns. The etiology of these disorders involves complex interactions between genetic vulnerability and environmental influences such as cultural idealization of thinness, early dieting behaviors, and experiences of discrimination. Primary care assessment relies on validated screening instruments like the SCOFF questionnaire, identification of physical markers including rapid weight loss, cardiac abnormalities, and electrolyte disturbances, and recognition of hospitalization indicators for severe malnutrition or cardiac complications. First-line psychotherapeutic interventions include family-based therapy for adolescents with anorexia nervosa and cognitive-behavioral approaches for adults and other presentations, with limited pharmacological options available. Sleep-wake disorders, particularly insomnia and restless legs syndrome, frequently signal underlying psychiatric pathology. Insomnia disorder involves persistent difficulty initiating or maintaining sleep occurring multiple nights weekly for extended periods, stemming from circadian rhythm misalignment and best addressed through cognitive-behavioral interventions focused on sleep restriction and sleep hygiene modification. Restless legs syndrome represents a sensorimotor condition characterized by an irresistible urge to move the legs triggered by uncomfortable sensations that intensify during rest periods, linked to dopaminergic dysfunction and iron metabolism disturbances and managed through dopaminergic pharmacotherapy and nutritional supplementation when indicated. The primary care provider assumes responsibility for early detection, medical differential diagnosis exclusion, patient education, and coordination with specialized multidisciplinary treatment teams.