Nerves, drugs, and madness + Evolutionary Psychology

Schizophrenia

• Type 1:
• Delusions
• Hallucinations
• Disorganised speech
• Disorganised behaviour;agitation
• Type 2:
• Catatonic behaviour
• Blunted emotions; loss of interest
• Appears during adolescence/early adulthood

Neurobiology of SZ

• Numerous brain abnormalities
• Enlarged ventricles
• thinner cortex
• poorer blood flow to prefrontal cortex
• loss of neuronal connections
• disorganised neurones in hippocampus
• changes in dopamine, glutamate, GABA and their receptors

'Dopamine hypothesis' of SZ

• Overuse of amphetamine found to produce symptoms like paranoid SZ in mid-20th century
• As amphetamine enhances dopamine activity, thought SZ is related to overactive dopamine
• Early antipsychotic drugs in part blocked DA receptors

Antipsychotic treatment

• Tardive dyskinesia - involuntary spasms and facial distortions from long-term antipsychotic use - often wrongly associated with madness rather than the treatment
• Clozapine - fewer motor effects, but other side effects include blood cell damage and weight gain

Mood disorders: Major Depressive Disorder/MDD

• prolonged loss of interest, feeling worthless, guilty, disrupted sleep and appetite
• may also be associated with considerable anxiety
• often considere to be two types of depression 1. endogenous - no obvious cause. 2. reactive - may result from stressful life events
• patients diagnosed to these categories do not appear consistently different, either in aetiology or treatment response
• Primary depression - no obvious cause
• Secondary depression - caused by another disorder

Bipolar disorder (manic depression)

• alternation between depression and intense excitation (mania) - cycle period varies greatly across people
• During mania (days to months) - hyperactive, change plans without completion, overconfident, insensitive to others, often leave broken relationships in their path.

Treatment of depression

• Mid-20th century: Monoamine Oxidase Inhibitors - prevent breakdown of NA, DA, 5-HT
• Tricyclis antidepressants (TCAs) - NA and 5-HT uptake inhibitors and other actions
• Selective Serotonin Reuptake Inhibitos - Prozac; more selective than TCAs thus fewer side effects - but not necessarily more effective
• SNRIs - Serotonin and Noradrenaline Reuptake Inhibitor

Drugs dont work at all for 20% of psychotic patients

• Electroconvulsive therapy
• noticed that psychotic patients improved after epileptic attacks
• Simulated by electric shock to head 
• improves depression and BD more quickly than drugs-usually used when drugs dont work
• Long-term use may damage memory, but may recover
• Psychosurgery is another option, as well as deep-brain stimulation; Vagus Nerve Stimulation; Transcranial Magnetic Stimulation

Treatment of Bipolar disorder

• ECT and TMS
• Anticonvulsant drugs show promise
• Lithium - chemical effective in suppressing mania, without preventing normal emotions

Treatment of Anxiety disorders

• Generalised Anxiety Disorder 
• Baribiturates - highly addictive and not very safe
• Benzodiazepines - indirect agonist for the GABA receptor; these drugs are used for their tranquilizing effects, can be used as sleeping pills, but much safer.
• Valium and Librium

Selecitve-hypnotic drugs like alcohol or barbiturates act like GABA, causing increased chloride conductance 

Antianxiety drugs (benzodiazepine) enhance the binding of GABA

Because of their different actions, these drugs should not be taken together.

- Sleeping pills/anxiolytics with similar drugs or alcohol should not be mixed.

 

Many drug treatments are hardly more effective than placebo, but may be most useful when combined with psychotherapy.

 

EVOLUTIONARY PSYCHOLOGY

• Human behaviour, thoughts and feelings can be understood by considering which behaviour, thoughts and feelings increased relative survival and reproduction
• Certain behaviour, T&F increased ancestral humans' abilities to have more offspring than less successful humans
• The offspring of these individuals inherited the genes coding for the same behaviour, T&F

Sexual selection

• Special case of natural selection
• Features selected for do not increase survival but increase reproductive success
• Females place higher importance on social status compared to males
• Females prefer older men who have access to resources, physical strength, increased knowledge, patience, and skill
• Females prefer athletic prowess; indicators of ability to protect her and children
• Men prefer younger women; youth and health; increased reproductive value
• Men prefer women who have wider hips; a mate who has the capacity to bear children

Genes linked with depression associated with immune and behavioural responses to infection

Homosexual orientation seems to defy evolutionary logic

 

Kin selection hypothesis

• homosexual males may have helped their relatives reproduce more succesfully by resource provision, child care and protection
• contribute to the overall fitness indirectly
• families with homosexual members would gain reproductive advantages in this way

Female fertility hypothesis

• Genes for homosexuality would persist in a population and be selected for if they increase fertility in female relations
• this increase would have to moe than compensate for reduced reproduction in male homosexuals
• maternal female relations of male homosexuals produce significantly more offspring
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