Section 10.4: Theoretical Models and Psychobiologic Bases of Behavior

Why Theory Is Tested

Nursing Practice V opens with the concepts of mental health, the psychobiologic bases of behavior, and the therapeutic models that explain why clients think, feel, and act as they do. Under the Enhanced Table of Specifications, these foundational items set up the harder application questions about psychopathology and therapeutic communication. Examinees who skip theory lose easy points and misread later scenarios, so this section builds that base.

The Major Theorists

Erikson is the most heavily tested developmental theorist because psychiatric and pediatric items map behavior to the age-appropriate crisis. For example, an adolescent struggling with peer identity is negotiating identity vs. role confusion.

Peplau's Phases of the Nurse-Client Relationship

Peplau reframed psychiatric nursing as an interpersonal process, and her phases structure nearly every therapeutic-relationship item:

1. Orientation phase: the nurse and client meet, establish trust, set boundaries, and clarify the purpose and time limits of the relationship. Contracting happens here.
2. Working phase: the client explores feelings and problems, and the nurse promotes insight, problem-solving, and behavior change. Most therapeutic work occurs here; transference and resistance may surface.
3. Termination (resolution) phase: the relationship ends; the nurse summarizes progress, addresses feelings of loss, and reinforces the client's independence. Introducing a new problem here should redirect to the plan for termination, not restart the working phase.

Maintaining professional boundaries across all phases is essential—self-disclosure is used sparingly and only for the client's benefit.

Defense Mechanisms

Freud's ego defense mechanisms are unconscious strategies that reduce anxiety. Common exam items ask you to name the mechanism in a vignette:

• Denial: refusing to accept reality (a newly diagnosed alcoholic insists he can stop anytime).
• Projection: attributing one's own unacceptable feelings to another.
• Displacement: shifting emotion to a safer target (yelling at family after a bad day).
• Rationalization: creating logical-sounding excuses.
• Regression: reverting to earlier behavior under stress (a hospitalized child wetting the bed).
• Sublimation: channeling impulses into acceptable activity (a healthy defense).

Psychobiologic Bases of Behavior

Modern psychiatric nursing recognizes that behavior has biological roots. Neurotransmitter imbalances underlie major disorders and explain why medications work:

• Dopamine excess is linked to the positive symptoms of schizophrenia (hallucinations, delusions); antipsychotics block dopamine receptors.
• Serotonin deficiency is associated with depression and anxiety; SSRIs raise serotonin availability.
• GABA (inhibitory) deficiency relates to anxiety; benzodiazepines enhance GABA.
• Norepinephrine dysregulation contributes to mood and anxiety disorders.

Understanding this psychobiologic frame connects theory directly to the psychopharmacology covered next, and reminds the nurse that mental illness is a health condition, not a character flaw—supporting a non-judgmental therapeutic stance.

Applying Erikson at the Bedside

Erikson's eight psychosocial stages are the workhorse of both psychiatric and pediatric items, so memorize the crisis for each age and the behavior that signals successful or unsuccessful resolution:

A hospitalized toddler who resists the nurse and insists on doing tasks alone is working on autonomy; the correct response supports safe independence rather than taking over.

Piaget and Cognitive Level

Piaget's cognitive stages guide age-appropriate teaching and communication. A preschooler in the preoperational stage is egocentric and takes language literally, so avoid phrases like "the doctor will put you to sleep." A school-age child in the concrete operational stage benefits from hands-on demonstration, while an adolescent in formal operations can reason abstractly about consequences.

Concepts of Mental Health

Mental health is more than the absence of illness - it is the capacity to form relationships, cope with stress, and function productively. The exam contrasts adaptive coping (problem-solving, seeking support, exercise) with maladaptive coping (denial, substance use, aggression). The stress-adaptation model frames symptoms as attempts to reduce anxiety, and Sullivan's and Peplau's interpersonal focus reminds the nurse that the therapeutic relationship itself is a treatment tool.

Linking Theory to Practice

These frameworks are not academic trivia; they drive nursing judgment. When a scenario describes an older adult reviewing life with regret, you recognize an unmet integrity vs. despair crisis and respond with reminiscence therapy. When a client projects blame onto staff, you recognize a defense mechanism and respond without defensiveness. Grounding behavior in theory and psychobiology keeps care individualized and non-judgmental, which is the stance NP V rewards throughout its items.