Schizophrenia

Neurobiology of SZ

'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

The Functional Neuroanatomy of the Human Visual System