Mood Disorder Diagnosis

Mood Disorders Overview

• Mood disorders include depressive disorders and bipolar disorders.

Depressive Disorders

• Major Depressive Disorder.
• Dysthymic Disorder.

Major Depressive Disorder

• Manifests as unipolar depression.
• Lifetime prevalence in women is up to 21%, and 13% in men.
• Onset typically occurs in the 20s, but can occur at any stage of life.

Mood Symptoms of Depression

• Persistent sad, depressed mood.
• Loss of interest or pleasure in previously enjoyable activities.
• DSM criteria require one of the above plus 4 additional symptoms for at least 2 weeks.

Physical Symptoms of Depression

• Sleep disturbance (too much or too little).
• Loss of energy, fatigue.
• Appetite disturbance/weight change (loss or increase in appetite).
• Changes in activity level (psychomotor retardation or agitation).

Cognitive Symptoms of Depression

• Difficulty concentrating and thinking.
• Difficulty making decisions.
• Feelings of worthlessness.
• Feelings of guilt or hopelessness.
• Recurrent thoughts of death or suicide.

Course of Depression

• If untreated, the average duration of the first episode is 6-9 months.
• Depression often recurs.

Dysthymic Disorder

• Dysthymic disorder is a less severe, but more chronic form of depression.
• Depressed mood is a key symptom.
• Two or more of the following symptoms need to be present.
  • Poor appetite or overeating.
  • Insomnia or hypersomnia.
  • Low energy or fatigue.
  • Low self-esteem.
  • Poor concentration or difficulty making decisions.
  • Feelings of hopelessness.

Dysthymic Disorder Duration

• Symptoms must last for at least 2 years.
• An individual should not be without symptoms for longer than 2 months.

Double-Depression

• Is dysthymic disorder with episodes of major depression.
• Has a more negative prognosis than either disorder alone.

Etiology of Depression

• Includes behavioral theory, cognitive-behavioral theories, and neurotransmitter models.
• Cognitive-behavioral theories include Aaron Beck's cognitive-behavioral theory and hopelessness theory.

Behavioral Theory of Depression

• Suggests depression is learned.
• Charles Ferster's view is that depression results from a lack of positive reinforcement for the depressive's actions.
• Peter Lewinsohn's view is that depression is caused by a combination of stressors in a person's environment and a lack of personal skills.

Criticisms

• It does not pay much attention to people's thoughts, perceptions, and evaluation.
• It focuses only on people's external and directly observable behavior.

Cognitive-Behavioral Theory

• Cognition plays an important role in determining the behavioral pattern of a person.
• Depression results from maladaptive, faulty, or irrational cognitions taking the form of distorted thoughts and judgments.
• It focuses on the ways in which people respond to negative experiences involving loss, failure, and disappointment.

Beck's Cognitive-Behavioral Theory

• Negative thoughts, generated by dysfunctional beliefs are the primary cause of depression.
• The depressive triad involves dysfunctional beliefs about:
  • The self.
  • The world.
  • The future.

Research Evidence for Cognitive Theory

• Halvorsen, Wang, Eisemann, Waterloo (2009) researched how early maladaptive schemas significantly predicted concurrent depression severity, and depression severity and episodes for major depression 9 years later.

Hopelessness Theory

• Suggests depression is caused by negative causal attributions (Abramson, et al., 1989).
• Depressogenic attributional styles include internal, stable, and global attributions.
  • Internal - "Failing the exam proves that I’m a loser.”
  • Stable - “I’ll never graduate because I’ve failed the exam”.
  • Global - “Bad things always happen to me”.
• Research evidence has yielded Inconsistent findings in children

Modified Hopelessness Theory

• The Weakest Link Hypothesis (Abela & Sarin, 2002) posits that vulnerability to depression is determined by the most depressogenic attributional style.
• Research (Abela & Sarin, 2002) among grade 7 students found that "Weakest links" interacted with negative events to predict increases in depression symptoms.

Take Home Message from Theories

• There is empirical support for the role of cognitive factors as a form of vulnerability to depression.
• Some theories can explain only certain aspects of depression.
• Integrating existing models may be necessary to attain a comprehensive model of depression.

Neurotransmitters and Depression

• Chemical substances that "physiologically influence the electrochemical states of nearby cells".
• Hyper- and hypo-activity of neurotransmitters can result in various behavioral changes.
• The discovery of neurotransmitter alterations has resulted in treatments for psychiatric disorders, most notably depression.
• In the 1950s, two classes of drugs were found to treat symptoms of depression:
  • Tricyclic antidepressants (TCA).
  • Monoamine oxidase inhibitors (MAOI).

Monoamine Hypothesis

• Suggests MDD may be explained as a result of monoamine neurotransmitter deficiencies.
• Links with at least 3 main neurotransmitters:
  • Norepinephrine.
  • Serotonin.
  • Dopamine.
• Most effects located in the midbrain and brain stem.

Catecholamine Hypothesis

• Arose from monoamine theories, especially Norepinephrine.
• Says depression is associated with decreases in catecholamines, particularly norepinephrine.
• Conversely, elation is associated with an excess of amines.

Norepinephrine (NE)

• Also known as noradrenaline.
• Has an integral function in the stress response system:
  • Regulates arousal.
  • Adaptation to environmental and internal stressors.
• Decreased levels of NE are often associated with MDD.
• Rapid reappearance of depressive symptoms occurs after drastic reduction of NE.

Serotonin (5-HT)

• Implicated shortly after catecholamines.
• Decrease in 5-HT is causally related in developing depression.
• Also, high amounts are associated with an individual's anxiety, obsessions, compulsions.
• Highest concentrations in the hypothalamus.

Dopamine

• Associated interest, pleasure, attention/concentration, and motivation.
• Reduced dopamine uptake is more present greater in those with MDD.
• Experimentally reduced dopamine transmission leads to feelings of anhedonia and deficits in reward processing.

Current Issues in Neurotransmitters

• The implications of other neurotransmitters such as the glutamate hypothesis of depression.
• What are the unique contributions of each neurotransmitter?
  • Nutt (2008) suggests that it may be possible to establish symptoms on a spectrum of negative affect, and by a loss of positive affect.
• Methodological issues can include inconsistencies with samples and diagnosis

Future Directions of study

• Gender effects, like discovering how neurotransmitter levels contribute to higher prevalence rates for women.
• Discovery of individual/unique contributions of neurotransmitters,.
• Whether there are underlying factors within a culture that contribute to neurotransmitter hypoactivity.

Conclusion

• Modeling MDD exclusively on neurotransmitter dysregulation is simplistic.
• However, it provides a basis through which researchers can study and provide further neurobiological evidence associated with MDD.
• Further work obviously needed, but current literature is a step in the right direction