Conditional Probabilities as a means of understanding Clinical Symptoms: The Role of Sensitivity, Specificity, PPP, and NPP

Transcription

1 Clinical Disorder Working Definition of a Clinical Disorder: a constellation of sym s that significantly im s an individual s ability to function, and is characterized by a particular sym picture with a specifiable on, c, dur, out, and response to t ment, and associated familial, psychosocial, and biological correlates. Onset: Course: age of initial symptoms + insidious vs rapid slowing worsening or improving; episodic vs chronic; waxing & waning vs continuous Duration: how long does a particular episode last? Outcome: do you fully recover?

2 Working Definition of a Clinical Disorder: a constellation of symptoms that significantly impairs an individual s ability to function, and is characterized by a particular symptom picture with a specifiable onset, course, duration, outcome, and response to treatment, and associated familial, psychosocial, and biological correlates. Onset: Course: age of initial symptoms + insidious vs rapid slowing worsening or improving; episodic vs chronic; waxing & waning vs continuous Duration: how long does a particular episode last? Outcome: do you fully recover?

3 Conditional Probabilities as a means of understanding Clinical Symptoms: The Role of Sensitivity, Specificity, PPP, and NPP

4 Differential Diagnosis & Conditional Probabilities Meets Dx Doesn t Meet Dx Symptom Present A E Symptom Absent B Sensitivity = A/B (true positive) The proportion of children with a particular disorder who exhibit a specific symptom; Specificity = C/D (true negative) The proportion of children without a particular disorder who do not exhibit a specific symptom; PPP = A/E The proportion of children with a particular symptom who meet diagnostic criteria for a particular disorder; NPP= C/F The proportion of children without a particular symptom who do not meet diagnostic criteria for a particular disorder C D F

5 What is epidemiology? Epidemiology is concerned with the ways in which clinical disorders and diseases occur in human popula7ons, and with factors that influence these pa;erns of occurrence. Three interrelated components of epidemiological research involve: 1. Assessing the occurrence of new cases (incidence rate) or exis7ng cases (prevalence rate) of the disorder at a given period of 7me or within a specific 7me period; [note: community vs clinic samples] 2. Assessing how the disorder is distributed in the popula7on, which may include informa7on concerning geographic loca7on, gender, socioeconomic level, and race; and 3. Iden7fying factors associated with the varia7on and distribu7on of the disorder to enable e7ological hypotheses to be generated.

6 The Role of Different Variables in Understanding Child Psychopathology

7 RELATIONSHIP AMONG VARIABLES? FACTORS INFLUENCING THE RELATIONSHIP BETWEEN VARIABLES? HOW DOES ANTECEDENT EXERT ITS INFLUENCE? CAN WE CONTROL OR ALTER THE OUTCOME? WHAT EFFECT DOES IV HAVE ON DV? CORRELATIONAL RESEARCH IDENTIFYING MARKERS IDENTIFYING RISK FACTORS MODERATORS/ PROTECTIVE FACTORS MEDIATORS PREVENTION/ TREATMENT EXPERIMENTAL RESEARCH TEMPORAL SEQUENCE UNKNOWN NON CAUSALLY RELATED TEMPORAL SEQUENCE ESTABLISHED- POSSIBLY CAUSAL NON- CAUSAL, BUT INFORMATIVE IDENTIFYING PROCESS/ MECHANISMS BY WHICH VARIABLES PRODUCE OUTCOMES/MODELS DECREASE PROBABILITY OF OCCURRENCE OR REDUCE CURRENT SYMPTOMS ESTABLISHING CAUSAL RELATIONSHIPS - MODELS

8 Mediators Mediator B Number of pirates X Global temp From: Journal of Irreproducible Results

9 Developmental Psychopathology A single cause? Direct vs. indirect effects: B Direct effect C Moderator A C Mediator B B A X C

10 Moderator Moderators Treatment Symptom reduction Hinshaw (2007) moderators of treatment response in ADHD Maternal depression

11 Rapport, Scanlan, & Denney (1999). J Child Psychology & Psychiatry D 31%.83 Scholastic Achievement.91.88*.87* Reading.42 E Math.48 E Language.50 E *.43* -.21(.716) -2.25(.598) 1.47(.186) E.50 Del E.42 Agg.87*.91* ADHD CD.67* -.28* IQ -.23*

12 E E COMPARATIVE FIT INDEX =.94 ROBUST FIT INDEX = E.66 B12 E E L H * B34 B56 D.60 AX E.46 L.89* BX E.50 H D.75.81*.84*.80*.97 D.51 Memory.40*.05(.009) D.71 Vigilance.72* 14.27(1.095).31*.05(.007) -.20* -.67(.153) (.494).48 Scholastic Achievement D.16*.55(.162) -.67* -.66(.037) 77%.91.89*.85* Reading Math Lang.19* 1.66(.579) Classroom Behavior.33*.13(.014) E E.52 E.55 D.91.96*.93* AS AP AE E E E E.50 Del E.42 Agg.87*.91* ADHD CD.67* -.28* IQ Rapport, Scanlan & Denney (1999) J. of Child Psychiatry and Psychology -.23*

13 MetaThought Language Biases in Psychopathology: Descrip7ons vs Evalua7ons ü pushy ü greedy ü manipula7ve ü ruthless ü stubborn ü intrusive ü exhibi7onist ü reckless ü troublemaker ü cheap ü rigid ü unfeeling ü oversensi7ve ü cowardly ü overly emo7onal ü abnormal ü weird ü dead ü sociopath Underscores the reciprocal influence of agtudes & language

14 MetaThought Language Biases in Psychopathology: Descrip7ons vs Evalua7ons ü pushy asser7ve ü greedy ambi7ous ü manipula7ve persuasive ü ruthless driven ü stubborn tenacious ü intrusive concerned ü exhibi7onist outgoing ü reckless brave ü troublemaker feisty ü cheap frugal ü rigid steadfast ü unfeeling nerves of steel ü oversensi7ve vulnerable ü cowardly self- protec7ve ü overly emo7onal passionate ü abnormal unique ü weird interes7ng ü dead ontologically impaired ü sociopath morally challenged Underscores the reciprocal influence of agtudes & language

15 Historical Influences Behaviorism and Social Learning Theory Behavior is learned- caused by interac9ons with the environment Classical Condi9oning how we are condi9oned to the environment through reflexive learning (high survival value) Pavlov Watson Operant Learning how we adjust/adapt to the environment via learning (high survival value with changing environment) Skinner Modeling how we learn from the environment through observa9on, instruc9on, and reading Bandura

16 Schema7c of Operant Condi7oning Rela7onships Outcome of Conditioning Increase Behavior Decrease Behavior Positive Stimulus Negative Stimulus Positive Reinforcement (add stimulus) Negative Reinforcement (remove stimulus) Response Cost (remove stimulus) Punishment (add stimulus)

17 Posi7ve Reinforcement a posi7vely viewed s7mulus follows a par7cular behavior and strengthens or increases the behavior. Nega7ve Reinforcement a nega7vely viewed s7mulus is removed or avoided and strengthens or increases the behavior that was performed (e.g., carrying an umbrella; giving in to a bra;y child); 2 primary types: avoidance and escape behavior Punishment a nega7vely viewed s7mulus is presented or occurs following a behavior and weakens or reduces future occurrences of the behavior (e.g., spanking). Response Cost a posi7ve s7mulus is removed and strengthens or increases a par7cular behavior (relies on the use of a posi7ve s7mulus or reinforcer and you lose parts of due to inappropriate behavior on your part). Ex7nc7on behavior is no longer followed by reinforcement and decreases and eventually ceases in frequency.

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19 S- d s discrimina9ve s9muli that indicate the likely occurrence of reinforcement. S- delta s s9muli that indicate the unlikely occurrence of reinforcement.

20 Basic Classical Condi7oning Learning UCS: Food [uncondi7oned S7mulus] elicits UCR: Saliva7on [no ini7al response to the neutral s7mulus becomes a condi7oned response] No condi7oning required Paired temporally Condi7oning required Neutral S7mulus: Bell [becomes a CS or condi7oned s7mulus ajer pairing

21 Uncondi9oned S9mulus (e.g., Shock; bombing) Repeated pairings Neutral S9mulus [memory of event] Elicits UCR Uncondi9oned Response (pain response/anxiety/ escape behavior) NS becomes a condi9oned s9mulus (CS) Now elicits a condi9oned response (CR) Condi9oned s9mulus is also associated with a memory representa9on of the US, which then leads to the produc9on of the CR the CS predicts the onset of the US and thus elicits a CR

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