4- Mood dx Flashcards
Historical Views (2)
Hippocrates:
- Melancholia (“black bile”) => depression
- Tx: “Bloodletting”
Kraepelin (medical model/classification of “syndromes”):
=> Refined unitary concept of “psychosis” into 2 distinct syndromes:
- Dementia Praecox: “Rapid cognitive disintegration” with disruption in attention, memory, and goal- directed beh => re-labelled “schizophrenia”
- Manic Depression: Primary mood disturbance with disruption in affective functioning => split into multiple mood dx
*Dominant view until mid 1950s
Unipolar-Bipolar Distinction
Karl Leonhard => distinction (somewhat modified) holds true today
- Unipolar: If patient experiences exclusively episodes of one pole (ex: only depressed or only manic) BUT Very rare to have only manic episodes
- Bipolar: Episodes of both mania and depression
DSM-5: Bipolar I Dx
Presence of a manic episode, lasting at least one week (most of the day, nearly every day) => with or w/o MDD
- Feeling “elevated”, “expansive mood” OR “extreme irritability”
- Persistently increased goal-directed activity or energy
Need 3 or more sx *4 if only irritable:
- Inflated self-esteem or grandiosity
- Decreased need for sleep
- More talkative than usual (pressured speech)
- Flight of ideas / racing thoughts
- Distractibility
- Increase in goal-directed (concrete or social) activity or psychomotor agitation
- Excessive involvement in pleasurable activities with a high potential for painful consequences
Need marked impairment for diagnosis => ex: Hospitalization, Psychotic features, Impairment in several domains (work, family, etc)
*Distress is NOT a factor in mania AND Not attributable to drugs or another medical condition
DSM-5: Bipolar II Dx and Cyclothymic Dx
Bipolar II: Presence of a hypomanic episode AND major depressive episode => Hypomania: Same sx criteria but only 4 days
Cyclothymic: Presence of hypomanic sx AND depressive sx that do not meet full criteria for period of at least 2 years
*Never without sx for more than 2 months at a time
*** Differential Dx: ADHD, Anxiety dx, BPD
DSM-5: Major Depressive Disorder
Presence of five or + sx within the same two-week period => All must be present SIMULTANEOUSLY
At least one must be one of two cardinal sx:
- Depressed mood
- Anhedonia
Need 4 or more sx:
- Weight loss or weight gain
- Insomnia or hypersomnia
- Fatigue or loss of energy
- Psychomotor agitation or retardation
- Feelings of worthlessness or excessive or inappropriate guilt
- Diminished ability to think or concentrate, or indecisiveness
- Recurrent thoughts of death, suicidal ideation or attempts
*Need history of depressive episodes, but no mania
DSM-5: Persistent Depressive Disorder
Depressed mood for at least 2 years (most of the day, nearly every day)
- Never without sx for more than 2 months at a time
Boundaries of Mood Dx and Tripartite Model
- Heterogeneity
- Comorbidity => Depression high with anxiety
Tripartite model:
- Specific to depression: Anhedonia
- Specific to anxiety: Physiological Hyperarousal
- Common feature: General distress/Negative affect
Epidemiology
Depression => MDD: 17% *Most diagnosed mood dx; PDD: 2.5-6%
Variable prevalence rates:
- Gender differences 2F: 1M
- Countries North America > Asia,Europe
- Ethnicity African Americans < Caucasian < Native Americans
- Low SES > High SES
Bipolar: 1-2%
Prevalence does not seem to differ as a function of gender, culture, countries, parts of the world => Fairly stable rates
- High SES? => Diagnostic bias (High SES = bipolar, Low SES = schizo)
Variable prevalence rates (Gender and cross-cultural)
Artefactual Reasons => Women are more likely to:
- Seek help
- Disclose depressive sx when asked
- Sx of depression have gender bias (ex: crying, weight changes / appetite)
Explanatory Factors
- Social roles => Women experience more stressors (ex: lack of status, power, control)
- Biological factors => Ovarian hormones (estrogen, progesterone) resulting in limbic system hyperactivation *inconclusive
- Diathesis-stress model?
Cross-cultural differences => Expression of depression may differ
- Frequently more somatic presentation in Asian, Latin American, and North African cultures ex: Headaches, loss of energy, sleeplessness
- More psychological sx in Western Cultures ex: Depressed, sad, feeling down
Changes over Time Depression and Bipolar
Increasing rates of bipolar and MDD over time (60s-75s)
Depression:
- People born after WWII have higher rates and earlier onset
- Leveling off in later years
- Persistent gender effect (more W)
- Persistent family effect
Implications for understanding etiology of depression:
- Can’t be fully attributed to artifacts => ex: changes in diagnostic criteria, social attitudes toward mental illness
- If rates in families are stable = may a changing environment (GxE) => urbanization, geographic mobility, social anomie, changes in family structure
Bipolar:
- Increasing rates of bipolar disorder among adults (2x) and youth (40x => very controversial)
- Most receive a psychotropic medication prescription (90.6% of youth)
=> Reason why DSM-5 added Disruptive Mood Dysregulation Disorder
Course and Tx Response
Depression
- Onset late adolescence – mid-20s
- 25% of the time, PDD then MDD
=> Episodes:
- 40-50% have recurring episodes
- 4-6 episodes over lifetime (average)
- Duration of episodes: 5-6 months
- 5-10% of people will covert to bipolar
Tx: Anti-depressants (ex: tricyclic, SSRIs)
Bipolar
- Onset age 20-30
- Often misdiagnosed (~60% originally classified as MDD)
=> Recurrent episodes - Periods of normal functioning in between
- Duration: manic < depressed
- More episodes than unipolar
- Duration of episode: 3-4 months
Tx: Mood stabilizers (Lithihum) and anti-convulsants
*Anti-depressants can trigger manic episodes in bipolar
Genetic Influences and Twin Studies
Family studies show genetic contribution for mood dx => Larger heritability estimates for bipolar vs unipolar
*First-degree relatives of person with bipolar are at elevated risk for both unipolar AND bipolar, but reverse is not true (risk for dep and not bipolar)
McGuffin Twin Study => Index twin and find co-twin, some MZ and DZ
Results (genes play some role especially for BD):
- Of MZ bipolar twins, 67% of co-twins had a mood disorder vs 19% co-twin for DZ bipolar twins => Suggests a 96% heritability
- Of MZ bipolar twins, 40% of co-twins had bipolar vs 5% co-twin for DZ bipolar twins => Suggests 70% heritability
- Of MZ MDD twins, 46% of co-twins had MDD vs 20% co-twin for DZ MDD twins => Suggests a 52% heritability
*Relatively small sample size
Kendler Twin Study =>15 493 complete twin pairs and dx interviews to assess MDD
Results:
- Overall heritability estimate: 38%
- Male twins: r=.31 for Mz, r=.11 for Dz
- Female twins: r=.44 for Mz, r=.16 for Dz
Shared/Non-Shared Env
Shared Environment
- Family-wide factors (ex: parental divorce)
- Variance often assumed to be negligible
- But some estimate 10- 19% of variance = shared environment
Non-Shared Environment
- Child-specific factors (ex: friends, classroom, specific parental relationships)
- Plays a big role
- Accounts for even more variance in MDD vs genetic variance
=> Gene-Env Correlation
Passive rGE
- Parents pass on depressogenic genes
- But also provide environment => Less warm and supportive, More chaos
Evocative rGE
- Child’s genes influence how others react to them => ex: Kids who will become depressed elicit + negative parenting
Active rGE
- Child’s genes influence their selection of environments => Kids who will become depressed avoid going out and engaging in pleasurable activities
Serotonin
Serotonin Transporter Polymorphism (5HTTPLR) => Determines (in part) how much serotonin taken back up into presynaptic neuron
- 2 alleles, short (s) and/or long (l)
- Short allele associated with slower reuptake of serotonin => Associated with depression
- Moderated by life stress (no/moderate/severe abuse)
*Issues of replicability with study (see ppx)
=> 80% of general public believes depression is caused by a “chemical imbalance” so assume that theory must be true since SSRIs work
*Correlation not causation
=> Other candidate genes: dopamine and cortisol
Psychological Factors: Stressful Life Events
Occurrence of stressful life events precipitates onset of MDD episode => ex: illness, assault, loss of loved one, marital problems, financial issues, interpersonal conflicts
- Depressed are + sensitive to the effects of stress => Especially to stressors relating to themes of loss and failure
=> Causality: Depressed people also generate more stress in their lives => Especially interpersonal stress
Two types of stressors:
- Dependent (stronger effect)
- Independent
=> Both dependent and independent stressors predict onset of depressive episode
=> Bipolar (Sheri Johnson)
- Stress appears to increase in the 1st 6 months prior to an episode
- Frequently relapse following a stressful experience
- Particular class of stressors important in mania: Goal-attainment events => achieve a goal, become very happy, subsequently dysregulation, spiral into mania
